//! Sub-agent spawning system.
//!
//! Provides tools to spawn background sub-agents, query their status,
//! and retrieve results. Sub-agents run with a filtered toolset and
//! inherit the workspace configuration from the main session.

use std::collections::{HashMap, VecDeque};
use std::fs;
use std::path::{Path, PathBuf};
use std::sync::Arc;
use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
use tokio::sync::Mutex;

use anyhow::{Result, anyhow};
use async_trait::async_trait;
use serde::{Deserialize, Serialize};
use serde_json::{Value, json};
use tokio::{sync::mpsc, task::JoinHandle};
use tokio_util::sync::CancellationToken;
use uuid::Uuid;

use crate::client::DeepSeekClient;
use crate::config::MAX_SUBAGENTS;
use crate::core::events::Event;
use crate::llm_client::LlmClient;
use crate::models::{ContentBlock, Message, MessageRequest, SystemPrompt, Tool};
use crate::tools::plan::{PlanState, SharedPlanState};
use crate::tools::registry::{ToolRegistry, ToolRegistryBuilder};
use crate::tools::spec::{
    ApprovalRequirement, ToolCapability, ToolContext, ToolError, ToolResult, ToolSpec,
    optional_bool, optional_u64, required_str,
};
use crate::tools::todo::{SharedTodoList, TodoList};
use crate::utils::spawn_supervised;

pub mod mailbox;
#[allow(unused_imports)]
pub use mailbox::{Mailbox, MailboxEnvelope, MailboxMessage, MailboxReceiver};

// === Constants ===

const DEFAULT_MAX_STEPS: u32 = 100;
const TOOL_TIMEOUT: Duration = Duration::from_secs(30);
/// Per-step LLM API call timeout. Each `create_message` request must complete
/// within this window or the step is treated as timed out. Prevents a single
/// stuck API call from blocking the sub-agent indefinitely.
const STEP_API_TIMEOUT: Duration = Duration::from_secs(120);
const RESULT_POLL_INTERVAL: Duration = Duration::from_millis(250);
const DEFAULT_RESULT_TIMEOUT_MS: u64 = 30_000;
const MIN_WAIT_TIMEOUT_MS: u64 = 10_000;
const MAX_RESULT_TIMEOUT_MS: u64 = 3_600_000;
const COMPLETED_AGENT_RETENTION: Duration = Duration::from_secs(60 * 60);
const SUBAGENT_STATE_SCHEMA_VERSION: u32 = 1;
const SUBAGENT_STATE_FILE: &str = "subagents.v1.json";
const SUBAGENT_RESTART_REASON: &str = "Interrupted by process restart";

const VALID_SUBAGENT_TYPES: &str =
    "general, explore, plan, review, custom, worker, explorer, awaiter, default";
pub const WHALE_NICKNAMES: &[&str] = &[
    "Blue",
    "Humpback",
    "Sperm",
    "Fin",
    "Sei",
    "Bryde's",
    "Minke",
    "Antarctic Minke",
    "Gray",
    "Bowhead",
    "North Atlantic Right",
    "North Pacific Right",
    "Southern Right",
    "Beluga",
    "Narwhal",
    "Orca",
    "Pilot",
    "False Killer",
    "Pygmy Killer",
    "Melon-headed",
    "Beaked",
    "Cuvier's Beaked",
    "Baird's Beaked",
    "Blainville's Beaked",
];

/// Removal version for deprecated tool aliases.
const DEPRECATION_REMOVAL_VERSION: &str = "0.8.0";

#[must_use]
pub fn whale_nickname_for_index(index: usize) -> String {
    let base = WHALE_NICKNAMES[index % WHALE_NICKNAMES.len()];
    if index < WHALE_NICKNAMES.len() {
        base.to_string()
    } else {
        format!("{base} {}", index / WHALE_NICKNAMES.len() + 1)
    }
}

// === Deprecation helpers ===

/// Wrap a `ToolResult` with a `_deprecation` block in its metadata.
///
/// Applied exclusively on alias paths (not on canonical tool names) so the
/// model can detect and migrate away from the old name before removal in
/// v`DEPRECATION_REMOVAL_VERSION`.
///
/// The `_deprecation` key is merged into any existing metadata so other
/// metadata (e.g. `status`, `timed_out`) is preserved unchanged.
fn wrap_with_deprecation_notice(
    mut result: ToolResult,
    this_tool: &str,
    use_instead: &str,
) -> ToolResult {
    tracing::warn!(
        "Deprecated tool '{}' invoked — use '{}' instead (removal: v{})",
        this_tool,
        use_instead,
        DEPRECATION_REMOVAL_VERSION,
    );

    let notice = json!({
        "_deprecation": {
            "this_tool": this_tool,
            "use_instead": use_instead,
            "removed_in": DEPRECATION_REMOVAL_VERSION,
            "message": format!(
                "Tool '{}' is deprecated; switch to '{}' before v{}.",
                this_tool, use_instead, DEPRECATION_REMOVAL_VERSION
            )
        }
    });

    result.metadata = Some(match result.metadata.take() {
        Some(Value::Object(mut map)) => {
            if let Value::Object(notice_map) = notice {
                map.extend(notice_map);
            }
            Value::Object(map)
        }
        Some(other) => {
            // Existing metadata was not an object — keep it as-is and add
            // the deprecation notice as a sibling under a wrapper.
            json!({ "_deprecation": notice["_deprecation"].clone(), "_original_metadata": other })
        }
        None => notice,
    });

    result
}

// === Types ===

/// Assignment metadata for sub-agent orchestration.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct SubAgentAssignment {
    pub objective: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub role: Option<String>,
}

impl SubAgentAssignment {
    fn new(objective: String, role: Option<String>) -> Self {
        Self { objective, role }
    }
}

/// Sub-agent execution types with specialized behavior and tool access.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Default)]
#[serde(rename_all = "snake_case")]
pub enum SubAgentType {
    /// General purpose - full tool access for multi-step tasks.
    #[default]
    General,
    /// Fast exploration - read-only tools for codebase search.
    Explore,
    /// Planning - analysis tools only for architectural planning.
    Plan,
    /// Code review - read + analysis tools.
    Review,
    /// Custom tool access defined at spawn time.
    Custom,
}

impl SubAgentType {
    /// Parse a sub-agent type from user input.
    #[must_use]
    pub fn from_str(s: &str) -> Option<Self> {
        match s.to_lowercase().as_str() {
            "general" | "general-purpose" | "general_purpose" | "worker" | "default" => {
                Some(Self::General)
            }
            "explore" | "exploration" | "explorer" => Some(Self::Explore),
            "plan" | "planning" | "awaiter" => Some(Self::Plan),
            "review" | "code-review" | "code_review" | "reviewer" => Some(Self::Review),
            "custom" => Some(Self::Custom),
            _ => None,
        }
    }

    #[must_use]
    pub fn as_str(&self) -> &'static str {
        match self {
            Self::General => "general",
            Self::Explore => "explore",
            Self::Plan => "plan",
            Self::Review => "review",
            Self::Custom => "custom",
        }
    }

    /// Get the system prompt for this agent type.
    #[must_use]
    pub fn system_prompt(&self) -> String {
        match self {
            Self::General => GENERAL_AGENT_PROMPT.to_string(),
            Self::Explore => EXPLORE_AGENT_PROMPT.to_string(),
            Self::Plan => PLAN_AGENT_PROMPT.to_string(),
            Self::Review => REVIEW_AGENT_PROMPT.to_string(),
            Self::Custom => CUSTOM_AGENT_PROMPT.to_string(),
        }
    }

    /// Get the default allowed tools for this agent type.
    ///
    /// **Deprecated since v0.6.6.** Default sub-agents now inherit the full
    /// parent registry; the per-type allowlist is advisory only. Pass an explicit
    /// `allowed_tools` array for narrow Custom roles instead.
    #[must_use]
    #[deprecated(
        since = "0.6.6",
        note = "Default sub-agents inherit the full parent registry; pass an explicit allowed_tools list only for narrow Custom roles."
    )]
    pub fn allowed_tools(&self) -> Vec<&'static str> {
        match self {
            Self::General => vec![
                "list_dir",
                "read_file",
                "write_file",
                "edit_file",
                "apply_patch",
                "grep_files",
                "file_search",
                "web.run",
                "web_search",
                "exec_shell",
                "exec_shell_wait",
                "exec_shell_interact",
                "exec_wait",
                "exec_interact",
                "note",
                "checklist_write",
                "checklist_add",
                "checklist_update",
                "checklist_list",
                "todo_write",
                "todo_add",
                "todo_update",
                "todo_list",
                "update_plan",
            ],
            Self::Explore => vec![
                "list_dir",
                "read_file",
                "grep_files",
                "file_search",
                "web.run",
                "web_search",
                "exec_shell",
                "exec_shell_wait",
                "exec_shell_interact",
                "exec_wait",
                "exec_interact",
            ],
            Self::Plan => vec![
                "list_dir",
                "read_file",
                "grep_files",
                "file_search",
                "web.run",
                "note",
                "update_plan",
                "checklist_write",
                "checklist_add",
                "checklist_update",
                "checklist_list",
                "todo_write",
                "todo_add",
                "todo_update",
                "todo_list",
            ],
            Self::Review => vec!["list_dir", "read_file", "grep_files", "file_search", "note"],
            Self::Custom => vec![], // Must be provided by caller.
        }
    }
}

/// Status of a sub-agent execution.
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum SubAgentStatus {
    Running,
    Completed,
    Interrupted(String),
    Failed(String),
    Cancelled,
}

/// Snapshot of sub-agent state for tool results.
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SubAgentResult {
    pub agent_id: String,
    pub agent_type: SubAgentType,
    pub assignment: SubAgentAssignment,
    #[serde(default)]
    pub model: String,
    #[serde(default, skip_serializing_if = "Option::is_none")]
    pub nickname: Option<String>,
    pub status: SubAgentStatus,
    pub result: Option<String>,
    pub steps_taken: u32,
    pub duration_ms: u64,
}

#[derive(Debug, Clone, Default)]
pub(crate) struct SubAgentSpawnOptions {
    pub model: Option<String>,
    pub nickname: Option<String>,
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum WaitMode {
    Any,
    All,
}

impl WaitMode {
    fn from_str(value: &str) -> Option<Self> {
        match value.to_ascii_lowercase().as_str() {
            "any" | "first" => Some(Self::Any),
            "all" => Some(Self::All),
            _ => None,
        }
    }

    fn as_str(self) -> &'static str {
        match self {
            Self::Any => "any",
            Self::All => "all",
        }
    }

    fn condition_met(self, snapshots: &[SubAgentResult]) -> bool {
        match self {
            Self::Any => snapshots
                .iter()
                .any(|snapshot| snapshot.status != SubAgentStatus::Running),
            Self::All => snapshots
                .iter()
                .all(|snapshot| snapshot.status != SubAgentStatus::Running),
        }
    }
}

#[derive(Debug, Clone)]
struct SubAgentInput {
    text: String,
    interrupt: bool,
}

#[derive(Debug, Clone)]
struct SpawnRequest {
    prompt: String,
    agent_type: SubAgentType,
    assignment: SubAgentAssignment,
    allowed_tools: Option<Vec<String>>,
    model: Option<String>,
    /// Optional working directory for the child. Must canonicalize to a
    /// path inside the parent's workspace. Used to dispatch parallel work
    /// into separate git worktrees: parent runs `git worktree add` first,
    /// then spawns children with the worktree path as `cwd`.
    cwd: Option<PathBuf>,
}

#[derive(Debug, Clone)]
struct AssignRequest {
    agent_id: String,
    objective: Option<String>,
    role: Option<String>,
    message: Option<String>,
    interrupt: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct PersistedSubAgent {
    id: String,
    agent_type: SubAgentType,
    prompt: String,
    assignment: SubAgentAssignment,
    #[serde(default)]
    model: String,
    #[serde(default)]
    nickname: Option<String>,
    status: SubAgentStatus,
    result: Option<String>,
    steps_taken: u32,
    duration_ms: u64,
    allowed_tools: Vec<String>,
    updated_at_ms: u64,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct PersistedSubAgentState {
    schema_version: u32,
    agents: Vec<PersistedSubAgent>,
}

impl Default for PersistedSubAgentState {
    fn default() -> Self {
        Self {
            schema_version: SUBAGENT_STATE_SCHEMA_VERSION,
            agents: Vec::new(),
        }
    }
}

/// Default cap on sub-agent recursion depth. Override via
/// `[runtime] max_spawn_depth = N` in `~/.deepseek/config.toml`.
pub const DEFAULT_MAX_SPAWN_DEPTH: u32 = 3;

/// Runtime configuration for spawning sub-agents.
///
/// Carries everything a child needs to (a) build its own tool registry —
/// including the manager so grandchildren can spawn — and (b) cooperate
/// with the rest of the spawn tree on cancellation and depth cap.
#[derive(Clone)]
pub struct SubAgentRuntime {
    pub client: DeepSeekClient,
    pub model: String,
    pub role_models: HashMap<String, String>,
    pub context: ToolContext,
    pub allow_shell: bool,
    pub event_tx: Option<mpsc::Sender<Event>>,
    /// Manager handle so children can recurse via `agent_spawn`. All agents
    /// at every depth share the same manager.
    pub manager: SharedSubAgentManager,
    /// Depth in the spawn tree. 0 = top-level user turn; 1 = direct child;
    /// etc. Children clone the parent runtime and increment this on spawn.
    pub spawn_depth: u32,
    /// Hard cap on recursion depth. A child whose `spawn_depth + 1` would
    /// exceed this is rejected at the spawn entry. Use `>` (strictly
    /// greater than) so equality is allowed — matches codex's pattern.
    pub max_spawn_depth: u32,
    /// Cooperative cancellation token. Children derive a child_token() from
    /// the parent so cancelling the root cascades down.
    pub cancel_token: CancellationToken,
    /// Structured progress / lifecycle stream. Cloned across children so the
    /// whole spawn tree publishes into one ordered, fan-out-able mailbox.
    /// `None` only when no consumer is wired (legacy entry points / tests).
    pub mailbox: Option<Mailbox>,
}

impl SubAgentRuntime {
    /// Create a top-level runtime configuration for sub-agent execution.
    /// Use this from the engine when constructing the runtime that the
    /// parent's tool registry passes through. Children should derive their
    /// runtime via `Self::child_runtime` instead.
    #[must_use]
    pub fn new(
        client: DeepSeekClient,
        model: String,
        context: ToolContext,
        allow_shell: bool,
        event_tx: Option<mpsc::Sender<Event>>,
        manager: SharedSubAgentManager,
    ) -> Self {
        Self {
            client,
            model,
            role_models: HashMap::new(),
            context,
            allow_shell,
            event_tx,
            manager,
            spawn_depth: 0,
            max_spawn_depth: DEFAULT_MAX_SPAWN_DEPTH,
            cancel_token: CancellationToken::new(),
            mailbox: None,
        }
    }

    /// Attach a `Mailbox` so this runtime (and every descendant — children
    /// clone it) publishes structured `MailboxMessage` envelopes alongside
    /// the legacy `Event` stream. Pair with [`Self::with_cancel_token`] when
    /// you want close-as-cancel to propagate the same way.
    #[must_use]
    #[allow(dead_code)] // wired by #128 (in-transcript cards) when it lands.
    pub fn with_mailbox(mut self, mailbox: Mailbox) -> Self {
        self.mailbox = Some(mailbox);
        self
    }

    /// Replace the cancellation token (e.g. when the engine constructs the
    /// runtime alongside a mailbox bound to the same token).
    #[must_use]
    #[allow(dead_code)] // wired by #128 alongside `with_mailbox`.
    pub fn with_cancel_token(mut self, token: CancellationToken) -> Self {
        self.cancel_token = token;
        self
    }

    /// Override the maximum spawn depth (default `DEFAULT_MAX_SPAWN_DEPTH`).
    /// Used by config wiring (`[runtime] max_spawn_depth = N`) and tests.
    #[must_use]
    #[allow(dead_code)]
    pub fn with_max_spawn_depth(mut self, max: u32) -> Self {
        self.max_spawn_depth = max;
        self
    }

    /// Attach raw role/type model overrides. Values are intentionally
    /// validated at spawn time so bad config fails before a partial spawn.
    #[must_use]
    pub fn with_role_models(mut self, role_models: HashMap<String, String>) -> Self {
        self.role_models = role_models;
        self
    }

    /// Return a child runtime that is deliberately detached from the parent
    /// turn cancellation token. Background sub-agents should keep running when
    /// the parent turn is cancelled; explicit agent/swarm cancellation still
    /// aborts their task handles through the manager.
    #[must_use]
    pub fn background_runtime(&self) -> Self {
        let mut runtime = self.child_runtime();
        let token = CancellationToken::new();
        runtime.cancel_token = token.clone();
        runtime.context.cancel_token = Some(token);
        runtime
    }

    /// Build a child runtime cloning this one, incrementing `spawn_depth`,
    /// deriving a child cancellation token, and forcing `auto_approve` on
    /// the child's `ToolContext`. Used at spawn entry to construct the
    /// runtime the new sub-agent will see.
    ///
    /// The `auto_approve` override is deliberate: spawning IS the approval.
    /// Per-tool prompts inside a child would break delegation, so children
    /// inherit a YOLO-equivalent context regardless of the parent's mode.
    /// The workspace boundary + sandbox profile still apply.
    #[must_use]
    pub fn child_runtime(&self) -> Self {
        let mut child_context = self.context.clone();
        child_context.auto_approve = true;
        Self {
            client: self.client.clone(),
            model: self.model.clone(),
            role_models: self.role_models.clone(),
            context: child_context,
            allow_shell: self.allow_shell,
            event_tx: self.event_tx.clone(),
            manager: self.manager.clone(),
            spawn_depth: self.spawn_depth + 1,
            max_spawn_depth: self.max_spawn_depth,
            cancel_token: self.cancel_token.child_token(),
            mailbox: self.mailbox.clone(),
        }
    }

    /// Whether the next spawn would exceed the depth cap.
    #[must_use]
    pub fn would_exceed_depth(&self) -> bool {
        self.spawn_depth + 1 > self.max_spawn_depth
    }
}

/// A running sub-agent instance.
pub struct SubAgent {
    pub id: String,
    pub agent_type: SubAgentType,
    pub prompt: String,
    pub assignment: SubAgentAssignment,
    pub model: String,
    pub nickname: Option<String>,
    pub status: SubAgentStatus,
    pub result: Option<String>,
    pub steps_taken: u32,
    pub started_at: Instant,
    /// `None` = full registry inheritance (v0.6.6 default).
    /// `Some(list)` = explicit narrow allowlist (Custom agents, legacy).
    pub allowed_tools: Option<Vec<String>>,
    input_tx: Option<mpsc::UnboundedSender<SubAgentInput>>,
    task_handle: Option<JoinHandle<()>>,
}

impl SubAgent {
    /// Create a new sub-agent.
    fn new(
        agent_type: SubAgentType,
        prompt: String,
        assignment: SubAgentAssignment,
        model: String,
        nickname: Option<String>,
        allowed_tools: Option<Vec<String>>,
        input_tx: mpsc::UnboundedSender<SubAgentInput>,
    ) -> Self {
        let id = format!("agent_{}", &Uuid::new_v4().to_string()[..8]);

        Self {
            id,
            agent_type,
            prompt,
            assignment,
            model,
            nickname,
            status: SubAgentStatus::Running,
            result: None,
            steps_taken: 0,
            started_at: Instant::now(),
            allowed_tools,
            input_tx: Some(input_tx),
            task_handle: None,
        }
    }

    /// Get a snapshot of the current state.
    #[must_use]
    pub fn snapshot(&self) -> SubAgentResult {
        SubAgentResult {
            agent_id: self.id.clone(),
            agent_type: self.agent_type.clone(),
            assignment: self.assignment.clone(),
            model: self.model.clone(),
            nickname: self.nickname.clone(),
            status: self.status.clone(),
            result: self.result.clone(),
            steps_taken: self.steps_taken,
            duration_ms: u64::try_from(self.started_at.elapsed().as_millis()).unwrap_or(u64::MAX),
        }
    }
}

/// Manager for active sub-agents.
pub struct SubAgentManager {
    agents: HashMap<String, SubAgent>,
    #[allow(dead_code)] // Stored for future workspace-scoped operations
    workspace: PathBuf,
    state_path: Option<PathBuf>,
    max_steps: u32,
    max_agents: usize,
}

impl SubAgentManager {
    /// Create a new manager for sub-agents.
    #[must_use]
    pub fn new(workspace: PathBuf, max_agents: usize) -> Self {
        Self {
            agents: HashMap::new(),
            workspace,
            state_path: None,
            max_steps: DEFAULT_MAX_STEPS,
            max_agents,
        }
    }

    #[must_use]
    fn with_state_path(mut self, path: PathBuf) -> Self {
        self.state_path = Some(path);
        self
    }

    fn persist_state(&self) -> Result<()> {
        let Some(path) = self.state_path.as_ref() else {
            return Ok(());
        };
        let now_ms = epoch_millis_now();
        let mut agents = Vec::with_capacity(self.agents.len());
        for agent in self.agents.values() {
            agents.push(PersistedSubAgent {
                id: agent.id.clone(),
                agent_type: agent.agent_type.clone(),
                prompt: agent.prompt.clone(),
                assignment: agent.assignment.clone(),
                model: agent.model.clone(),
                nickname: agent.nickname.clone(),
                status: agent.status.clone(),
                result: agent.result.clone(),
                steps_taken: agent.steps_taken,
                duration_ms: u64::try_from(agent.started_at.elapsed().as_millis())
                    .unwrap_or(u64::MAX),
                // Backward-compat: Vec on disk. None → empty vec; Some(list) → list.
                // Reload converts empty vec back to None (full inheritance).
                allowed_tools: agent.allowed_tools.clone().unwrap_or_default(),
                updated_at_ms: now_ms,
            });
        }
        agents.sort_by(|a, b| a.id.cmp(&b.id));

        let payload = PersistedSubAgentState {
            schema_version: SUBAGENT_STATE_SCHEMA_VERSION,
            agents,
        };
        write_json_atomic(path, &payload)
    }

    fn persist_state_best_effort(&self) {
        if let Err(err) = self.persist_state() {
            eprintln!("Failed to persist sub-agent state: {err}");
        }
    }

    fn load_state(&mut self) -> Result<()> {
        let Some(path) = self.state_path.as_ref() else {
            return Ok(());
        };
        if !path.exists() {
            return Ok(());
        }

        let raw = fs::read_to_string(path)?;
        let state = serde_json::from_str::<PersistedSubAgentState>(&raw)?;
        if state.schema_version != SUBAGENT_STATE_SCHEMA_VERSION {
            return Err(anyhow!(
                "Unsupported sub-agent state schema {}",
                state.schema_version
            ));
        }

        self.agents.clear();
        for persisted in state.agents {
            let mut status = persisted.status;
            if matches!(status, SubAgentStatus::Running) {
                status = SubAgentStatus::Interrupted(SUBAGENT_RESTART_REASON.to_string());
            }

            let started_at = instant_from_duration(Duration::from_millis(persisted.duration_ms));
            // Empty vec on disk → None (full inheritance, v0.6.6 default).
            // Non-empty vec → Some(list) (preserves narrow scope from older sessions).
            let allowed_tools = if persisted.allowed_tools.is_empty() {
                None
            } else {
                Some(persisted.allowed_tools)
            };
            let agent = SubAgent {
                id: persisted.id.clone(),
                agent_type: persisted.agent_type,
                prompt: persisted.prompt,
                assignment: persisted.assignment,
                model: if persisted.model.is_empty() {
                    "unknown".to_string()
                } else {
                    persisted.model
                },
                nickname: persisted.nickname,
                status,
                result: persisted.result,
                steps_taken: persisted.steps_taken,
                started_at,
                allowed_tools,
                input_tx: None,
                task_handle: None,
            };
            self.agents.insert(persisted.id, agent);
        }

        Ok(())
    }

    /// Count running agents.
    pub fn running_count(&self) -> usize {
        self.agents
            .values()
            .filter(|agent| {
                if agent.status != SubAgentStatus::Running {
                    return false;
                }
                !agent
                    .task_handle
                    .as_ref()
                    .is_some_and(tokio::task::JoinHandle::is_finished)
            })
            .count()
    }

    /// Spawn a new background sub-agent.
    pub fn spawn_background(
        &mut self,
        manager_handle: SharedSubAgentManager,
        runtime: SubAgentRuntime,
        agent_type: SubAgentType,
        prompt: String,
        allowed_tools: Option<Vec<String>>,
    ) -> Result<SubAgentResult> {
        self.spawn_background_with_assignment(
            manager_handle,
            runtime,
            agent_type,
            prompt.clone(),
            SubAgentAssignment::new(prompt, None),
            allowed_tools,
        )
    }

    /// Spawn a new background sub-agent with explicit assignment metadata.
    pub fn spawn_background_with_assignment(
        &mut self,
        manager_handle: SharedSubAgentManager,
        runtime: SubAgentRuntime,
        agent_type: SubAgentType,
        prompt: String,
        assignment: SubAgentAssignment,
        allowed_tools: Option<Vec<String>>,
    ) -> Result<SubAgentResult> {
        self.spawn_background_with_assignment_options(
            manager_handle,
            runtime,
            agent_type,
            prompt,
            assignment,
            allowed_tools,
            SubAgentSpawnOptions::default(),
        )
    }

    /// Spawn a new background sub-agent with explicit assignment and display
    /// metadata.
    #[allow(clippy::too_many_arguments)]
    pub(crate) fn spawn_background_with_assignment_options(
        &mut self,
        manager_handle: SharedSubAgentManager,
        mut runtime: SubAgentRuntime,
        agent_type: SubAgentType,
        prompt: String,
        assignment: SubAgentAssignment,
        allowed_tools: Option<Vec<String>>,
        options: SubAgentSpawnOptions,
    ) -> Result<SubAgentResult> {
        self.cleanup(COMPLETED_AGENT_RETENTION);

        if self.running_count() >= self.max_agents {
            return Err(anyhow!(
                "Sub-agent limit reached (max {}, running {}). Cancel, close, or wait for an existing agent to finish. Consider issuing multiple tool calls in one turn (the dispatcher runs them in parallel) for parallel one-shot work.",
                self.max_agents,
                self.running_count()
            ));
        }

        if let Some(model) = options.model.as_deref() {
            runtime.model = model.to_string();
        }
        let effective_model = runtime.model.clone();
        let nickname = options
            .nickname
            .or_else(|| Some(whale_nickname_for_index(self.agents.len())));
        let tools = build_allowed_tools(&agent_type, allowed_tools, runtime.allow_shell)?;
        let (input_tx, input_rx) = mpsc::unbounded_channel();
        let mut agent = SubAgent::new(
            agent_type.clone(),
            prompt.clone(),
            assignment.clone(),
            effective_model,
            nickname,
            tools.clone(),
            input_tx,
        );
        let agent_id = agent.id.clone();
        let started_at = agent.started_at;
        let max_steps = self.max_steps;

        if let Some(event_tx) = runtime.event_tx.clone() {
            let _ = event_tx.try_send(Event::AgentSpawned {
                id: agent_id.clone(),
                prompt: prompt.clone(),
            });
        }

        let task = SubAgentTask {
            manager_handle,
            runtime,
            agent_id: agent_id.clone(),
            agent_type,
            prompt,
            assignment,
            allowed_tools: tools,
            started_at,
            max_steps,
            input_rx,
        };
        let handle = spawn_supervised(
            "subagent-task",
            std::panic::Location::caller(),
            run_subagent_task(task),
        );
        agent.task_handle = Some(handle);
        self.agents.insert(agent_id.clone(), agent);
        self.persist_state_best_effort();

        Ok(self
            .agents
            .get(&agent_id)
            .expect("agent should exist after spawn")
            .snapshot())
    }

    /// Get the current snapshot for an agent.
    pub fn get_result(&self, agent_id: &str) -> Result<SubAgentResult> {
        let agent = self
            .agents
            .get(agent_id)
            .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;
        Ok(agent.snapshot())
    }

    /// Cancel a running sub-agent.
    pub fn cancel(&mut self, agent_id: &str) -> Result<SubAgentResult> {
        let (snapshot, changed) = {
            let agent = self
                .agents
                .get_mut(agent_id)
                .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;

            let mut changed = false;
            if agent.status == SubAgentStatus::Running {
                agent.status = SubAgentStatus::Cancelled;
                if let Some(handle) = agent.task_handle.take() {
                    handle.abort();
                }
                changed = true;
            }
            (agent.snapshot(), changed)
        };

        if changed {
            self.persist_state_best_effort();
        }
        Ok(snapshot)
    }

    /// Resume a non-running sub-agent by restarting it with the original assignment.
    pub fn resume(
        &mut self,
        manager_handle: SharedSubAgentManager,
        runtime: SubAgentRuntime,
        agent_id: &str,
    ) -> Result<SubAgentResult> {
        let status = self
            .agents
            .get(agent_id)
            .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?
            .status
            .clone();

        if status == SubAgentStatus::Running {
            let agent = self
                .agents
                .get(agent_id)
                .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;
            return Ok(agent.snapshot());
        }

        if self.running_count() >= self.max_agents {
            return Err(anyhow!(
                "Sub-agent limit reached (max {}, running {}). Close or wait for an existing agent before resuming. Consider issuing multiple tool calls in one turn (the dispatcher runs them in parallel) for parallel one-shot work.",
                self.max_agents,
                self.running_count()
            ));
        }

        let snapshot = {
            let agent = self
                .agents
                .get_mut(agent_id)
                .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;

            let (input_tx, input_rx) = mpsc::unbounded_channel();
            let restarted_at = Instant::now();
            let mut restart_runtime = runtime.clone();
            if !agent.model.trim().is_empty() && agent.model != "unknown" {
                restart_runtime.model.clone_from(&agent.model);
            }
            let task = SubAgentTask {
                manager_handle,
                runtime: restart_runtime,
                agent_id: agent.id.clone(),
                agent_type: agent.agent_type.clone(),
                prompt: agent.prompt.clone(),
                assignment: agent.assignment.clone(),
                allowed_tools: agent.allowed_tools.clone(),
                started_at: restarted_at,
                max_steps: self.max_steps,
                input_rx,
            };
            let handle = spawn_supervised(
                "subagent-task-resume",
                std::panic::Location::caller(),
                run_subagent_task(task),
            );

            agent.status = SubAgentStatus::Running;
            agent.result = None;
            agent.steps_taken = 0;
            agent.started_at = restarted_at;
            agent.input_tx = Some(input_tx);
            agent.task_handle = Some(handle);

            if let Some(event_tx) = runtime.event_tx {
                let _ = event_tx.try_send(Event::AgentSpawned {
                    id: agent.id.clone(),
                    prompt: format!("(resumed) {}", agent.prompt),
                });
            }

            agent.snapshot()
        };
        self.persist_state_best_effort();

        Ok(snapshot)
    }

    /// Send input to a running sub-agent.
    pub fn send_input(&mut self, agent_id: &str, text: String, interrupt: bool) -> Result<()> {
        let agent = self
            .agents
            .get_mut(agent_id)
            .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;

        if agent.status != SubAgentStatus::Running {
            return Err(anyhow!("Agent {agent_id} is not running"));
        }

        let tx = agent
            .input_tx
            .as_ref()
            .ok_or_else(|| anyhow!("Agent {agent_id} cannot accept input"))?;

        tx.send(SubAgentInput { text, interrupt })
            .map_err(|_| anyhow!("Failed to send input to agent {agent_id}"))?;

        Ok(())
    }

    /// Update assignment metadata and optionally send immediate guidance.
    pub fn assign(
        &mut self,
        agent_id: &str,
        objective: Option<String>,
        role: Option<String>,
        message: Option<String>,
        interrupt: bool,
    ) -> Result<SubAgentResult> {
        if objective.is_none() && role.is_none() && message.is_none() {
            return Err(anyhow!(
                "Provide at least one of objective, role, or message"
            ));
        }

        if message.is_some() {
            let status = self
                .agents
                .get(agent_id)
                .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?
                .status
                .clone();
            if status != SubAgentStatus::Running {
                return Err(anyhow!(
                    "Agent {agent_id} is not running; cannot deliver assignment message"
                ));
            }
        }

        let mut changed = false;
        let (input_tx, payload) = {
            let agent = self
                .agents
                .get_mut(agent_id)
                .ok_or_else(|| anyhow!("Agent {agent_id} not found"))?;

            let mut assignment_lines = Vec::new();
            if let Some(objective) = objective {
                let objective = objective.trim();
                if objective.is_empty() {
                    return Err(anyhow!("objective cannot be empty"));
                }
                if agent.assignment.objective != objective {
                    agent.assignment.objective = objective.to_string();
                    changed = true;
                }
                assignment_lines.push(format!("- objective: {}", agent.assignment.objective));
            }

            if let Some(role) = role {
                let normalized = normalize_role_alias(&role)
                    .ok_or_else(|| {
                        anyhow!(
                            "Invalid role alias '{role}'. Use: worker, explorer, awaiter, default"
                        )
                    })?
                    .to_string();
                if agent.assignment.role.as_deref() != Some(normalized.as_str()) {
                    agent.assignment.role = Some(normalized.clone());
                    changed = true;
                }
                assignment_lines.push(format!("- role: {normalized}"));
            }

            let mut payload_parts = Vec::new();
            if !assignment_lines.is_empty() && agent.status == SubAgentStatus::Running {
                payload_parts.push(format!(
                    "Assignment updated:\n{}",
                    assignment_lines.join("\n")
                ));
            }
            if let Some(message) = message {
                let message = message.trim();
                if message.is_empty() {
                    return Err(anyhow!("message cannot be empty"));
                }
                payload_parts.push(format!("Coordinator note:\n{message}"));
            }

            let payload = if payload_parts.is_empty() {
                None
            } else {
                Some(payload_parts.join("\n\n"))
            };

            (agent.input_tx.clone(), payload)
        };

        if let Some(payload) = payload {
            let tx = input_tx
                .ok_or_else(|| anyhow!("Agent {agent_id} cannot accept assignment input"))?;
            tx.send(SubAgentInput {
                text: payload,
                interrupt,
            })
            .map_err(|_| anyhow!("Failed to send assignment to agent {agent_id}"))?;
        }

        if changed {
            self.persist_state_best_effort();
        }

        self.get_result(agent_id)
    }

    /// List all agents and their status.
    #[must_use]
    pub fn list(&self) -> Vec<SubAgentResult> {
        self.agents.values().map(SubAgent::snapshot).collect()
    }

    /// Clean up completed agents older than the given duration.
    pub fn cleanup(&mut self, max_age: Duration) {
        let before = self.agents.len();
        self.agents.retain(|_, agent| {
            if agent.status == SubAgentStatus::Running {
                true
            } else {
                agent.started_at.elapsed() < max_age
            }
        });
        if self.agents.len() != before {
            self.persist_state_best_effort();
        }
    }

    fn update_from_result(&mut self, agent_id: &str, result: SubAgentResult) {
        let mut changed = false;
        if let Some(agent) = self.agents.get_mut(agent_id) {
            agent.status = result.status;
            agent.assignment = result.assignment;
            agent.result = result.result;
            agent.steps_taken = result.steps_taken;
            agent.task_handle = None;
            changed = true;
        }
        if changed {
            self.persist_state_best_effort();
        }
    }

    fn update_failed(&mut self, agent_id: &str, error: String) {
        let mut changed = false;
        if let Some(agent) = self.agents.get_mut(agent_id) {
            agent.status = SubAgentStatus::Failed(error);
            agent.task_handle = None;
            changed = true;
        }
        if changed {
            self.persist_state_best_effort();
        }
    }
}

/// Thread-safe wrapper for `SubAgentManager`.
pub type SharedSubAgentManager = Arc<Mutex<SubAgentManager>>;

fn default_state_path(workspace: &Path) -> PathBuf {
    workspace
        .join(".deepseek")
        .join("state")
        .join(SUBAGENT_STATE_FILE)
}

fn epoch_millis_now() -> u64 {
    match SystemTime::now().duration_since(UNIX_EPOCH) {
        Ok(duration) => u64::try_from(duration.as_millis()).unwrap_or(u64::MAX),
        Err(_) => 0,
    }
}

fn instant_from_duration(duration: Duration) -> Instant {
    Instant::now()
        .checked_sub(duration)
        .unwrap_or_else(Instant::now)
}

fn write_json_atomic<T: Serialize>(path: &Path, value: &T) -> Result<()> {
    if let Some(parent) = path.parent() {
        fs::create_dir_all(parent)?;
    }
    let payload = serde_json::to_string_pretty(value)?;
    let tmp_path = path.with_extension("tmp");
    fs::write(&tmp_path, payload)?;
    fs::rename(tmp_path, path)?;
    Ok(())
}

/// Create a shared sub-agent manager with a configurable limit.
#[must_use]
pub fn new_shared_subagent_manager(workspace: PathBuf, max_agents: usize) -> SharedSubAgentManager {
    let max_agents = max_agents.clamp(1, MAX_SUBAGENTS);
    let state_path = default_state_path(&workspace);
    let mut manager = SubAgentManager::new(workspace, max_agents).with_state_path(state_path);
    if let Err(err) = manager.load_state() {
        eprintln!("Failed to load sub-agent state: {err}");
    }
    Arc::new(Mutex::new(manager))
}

// === Tool Implementations ===

/// Tool to spawn a background sub-agent.
pub struct AgentSpawnTool {
    manager: SharedSubAgentManager,
    runtime: SubAgentRuntime,
    name: &'static str,
}

impl AgentSpawnTool {
    /// Create a new spawn tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, runtime: SubAgentRuntime) -> Self {
        Self::with_name(manager, runtime, "agent_spawn")
    }

    /// Create a new spawn tool with a custom tool name alias.
    #[must_use]
    pub fn with_name(
        manager: SharedSubAgentManager,
        runtime: SubAgentRuntime,
        name: &'static str,
    ) -> Self {
        Self {
            manager,
            runtime,
            name,
        }
    }
}

#[async_trait]
impl ToolSpec for AgentSpawnTool {
    fn name(&self) -> &'static str {
        self.name
    }

    fn description(&self) -> &'static str {
        "Spawn a background sub-agent for a focused task. Returns an agent_id immediately; \
         follow with agent_result to retrieve the final result. Max 5 in flight (each is a \
         full sub-agent loop; cancel or wait if you hit the cap). For parallel one-shot LLM \
         queries, just emit multiple tool calls in one turn — the dispatcher runs them in parallel."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "prompt": {
                    "type": "string",
                    "description": "Task description for the sub-agent"
                },
                "message": {
                    "type": "string",
                    "description": "Alias for prompt"
                },
                "objective": {
                    "type": "string",
                    "description": "Alias for prompt"
                },
                "items": {
                    "type": "array",
                    "description": "Structured input items (text, mention, skill, local_image, image)",
                    "items": {
                        "type": "object"
                    }
                },
                "type": {
                    "type": "string",
                    "description": "Sub-agent type: general, explore, plan, review, custom"
                },
                "agent_type": {
                    "type": "string",
                    "description": "Alias for type"
                },
                "agent_name": {
                    "type": "string",
                    "description": "Alias for type"
                },
                "role": {
                    "type": "string",
                    "description": "Role alias: worker, explorer, awaiter, default"
                },
                "agent_role": {
                    "type": "string",
                    "description": "Alias for role"
                },
                "allowed_tools": {
                    "type": "array",
                    "items": { "type": "string" },
                    "description": "Explicit tool allowlist (required for custom type). Default behavior is full registry inheritance from the parent."
                },
                "model": {
                    "type": "string",
                    "description": "Optional DeepSeek model id for this child. Explicit model wins over role/type defaults; omit to inherit."
                },
                "cwd": {
                    "type": "string",
                    "description": "Optional working directory for the child. Must be inside the parent's workspace (use a relative path or an absolute path under the workspace root). Used for the parallel-worktree pattern: parent runs `git worktree add .worktrees/feature-x ...` then spawns the child with `cwd: \".worktrees/feature-x\"`."
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![
            ToolCapability::ExecutesCode,
            ToolCapability::RequiresApproval,
        ]
    }

    fn approval_requirement(&self) -> ApprovalRequirement {
        ApprovalRequirement::Required
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let spawn_request = parse_spawn_request(&input)?;

        // Depth cap: reject before locking the manager so we don't introduce
        // unnecessary contention. Mirrors codex's pattern (allow-equal at the
        // boundary; reject when `next > max`).
        if self.runtime.would_exceed_depth() {
            return Err(ToolError::execution_failed(format!(
                "Sub-agent depth limit reached (current depth {}, max {}). \
                 Increase via [runtime] max_spawn_depth in config.toml.",
                self.runtime.spawn_depth, self.runtime.max_spawn_depth
            )));
        }

        // Validate cwd if supplied: must canonicalize inside the parent
        // workspace. Catches accidents like `cwd: "/etc"`.
        let validated_cwd = if let Some(requested_cwd) = spawn_request.cwd.as_ref() {
            let parent_workspace = &self.runtime.context.workspace;
            let resolved = if requested_cwd.is_absolute() {
                requested_cwd.clone()
            } else {
                parent_workspace.join(requested_cwd)
            };
            let canonical = resolved.canonicalize().map_err(|e| {
                ToolError::invalid_input(format!(
                    "Invalid cwd '{}': {e} (path may not exist yet — create the worktree first)",
                    requested_cwd.display()
                ))
            })?;
            let workspace_canonical = parent_workspace
                .canonicalize()
                .unwrap_or_else(|_| parent_workspace.clone());
            if !canonical.starts_with(&workspace_canonical) {
                return Err(ToolError::invalid_input(format!(
                    "cwd must be inside the parent workspace: {} is not under {}",
                    canonical.display(),
                    workspace_canonical.display()
                )));
            }
            Some(canonical)
        } else {
            None
        };

        // Derive the child's runtime as a durable background job: it keeps
        // its own cancellation token, forces auto_approve, and optionally
        // overrides cwd if the caller passed one (used for the parallel-
        // worktree pattern).
        let mut child_runtime = self.runtime.background_runtime();
        if let Some(cwd) = validated_cwd {
            child_runtime.context.workspace = cwd;
        }
        let effective_model = match spawn_request.model.clone() {
            Some(model) => model,
            None => configured_model_for_role_or_type(
                &self.runtime,
                spawn_request.assignment.role.as_deref(),
                &spawn_request.agent_type,
            )?
            .unwrap_or_else(|| self.runtime.model.clone()),
        };
        child_runtime.model = effective_model.clone();

        let mut manager = self.manager.lock().await;

        let result = manager
            .spawn_background_with_assignment_options(
                Arc::clone(&self.manager),
                child_runtime,
                spawn_request.agent_type,
                spawn_request.prompt,
                spawn_request.assignment,
                spawn_request.allowed_tools,
                SubAgentSpawnOptions {
                    model: Some(effective_model),
                    nickname: None,
                },
            )
            .map_err(|e| ToolError::execution_failed(format!("Failed to spawn sub-agent: {e}")))?;

        let mut tool_result = if self.name == "spawn_agent" {
            let payload = json!({
                "agent_id": result.agent_id.clone(),
                "nickname": result.nickname.clone(),
                "model": result.model.clone()
            });
            ToolResult::json(&payload).map_err(|e| ToolError::execution_failed(e.to_string()))?
        } else {
            ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))?
        };
        if result.status == SubAgentStatus::Running {
            if self.name == "spawn_agent" {
                tool_result.metadata = Some(json!({
                    "status": "Running",
                    "snapshot": result
                }));
            } else {
                tool_result.metadata = Some(json!({ "status": "Running" }));
            }
        }
        // Annotate alias invocations with a deprecation notice so the model
        // can migrate to the canonical name before removal in v0.8.0.
        if self.name == "spawn_agent" {
            tool_result = wrap_with_deprecation_notice(tool_result, "spawn_agent", "agent_spawn");
        }
        Ok(tool_result)
    }
}

/// Tool to fetch a sub-agent's result.
pub struct AgentResultTool {
    manager: SharedSubAgentManager,
}

impl AgentResultTool {
    /// Create a new result tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager) -> Self {
        Self { manager }
    }
}

#[async_trait]
impl ToolSpec for AgentResultTool {
    fn name(&self) -> &'static str {
        "agent_result"
    }

    fn description(&self) -> &'static str {
        "Get the latest status or final result for a sub-agent. Set `block: true` to wait until the \
         agent reaches a terminal state (respects `timeout_ms`)."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "agent_id": {
                    "type": "string",
                    "description": "ID returned by agent_spawn"
                },
                "id": {
                    "type": "string",
                    "description": "Alias for agent_id"
                },
                "block": {
                    "type": "boolean",
                    "description": "Wait for completion (default: false)"
                },
                "timeout_ms": {
                    "type": "integer",
                    "description": "Max wait time in milliseconds (default: 30000, clamped to 1000-3600000)"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![ToolCapability::ReadOnly]
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let agent_id = input
            .get("agent_id")
            .or_else(|| input.get("id"))
            .and_then(|v| v.as_str())
            .ok_or_else(|| ToolError::missing_field("agent_id"))?;
        let block = optional_bool(&input, "block", false);
        let timeout_ms = optional_u64(&input, "timeout_ms", DEFAULT_RESULT_TIMEOUT_MS)
            .clamp(1000, MAX_RESULT_TIMEOUT_MS);

        let (result, timed_out) = if block {
            wait_for_result(&self.manager, agent_id, Duration::from_millis(timeout_ms)).await?
        } else {
            let manager = self.manager.lock().await;
            (
                manager
                    .get_result(agent_id)
                    .map_err(|e| ToolError::execution_failed(e.to_string()))?,
                false,
            )
        };

        let mut tool_result =
            ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))?;
        if timed_out {
            tool_result.metadata = Some(json!({
                "status": "TimedOut",
                "timed_out": true,
                "timeout_ms": timeout_ms
            }));
        } else if result.status == SubAgentStatus::Running {
            tool_result.metadata = Some(json!({ "status": "Running" }));
        }
        Ok(tool_result)
    }
}

/// Tool to cancel a sub-agent.
pub struct AgentCancelTool {
    manager: SharedSubAgentManager,
}

impl AgentCancelTool {
    /// Create a new cancel tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager) -> Self {
        Self { manager }
    }
}

#[async_trait]
impl ToolSpec for AgentCancelTool {
    fn name(&self) -> &'static str {
        "agent_cancel"
    }

    fn description(&self) -> &'static str {
        "Cancel a running sub-agent. Returns the final snapshot with the cancelled status."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "agent_id": {
                    "type": "string",
                    "description": "ID returned by agent_spawn"
                }
            },
            "required": ["agent_id"]
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![
            ToolCapability::ExecutesCode,
            ToolCapability::RequiresApproval,
        ]
    }

    fn approval_requirement(&self) -> ApprovalRequirement {
        ApprovalRequirement::Required
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let agent_id = required_str(&input, "agent_id")?;
        let mut manager = self.manager.lock().await;
        let result = manager
            .cancel(agent_id)
            .map_err(|e| ToolError::execution_failed(format!("Failed to cancel sub-agent: {e}")))?;

        ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))
    }
}

/// Tool to list all sub-agents.
pub struct AgentListTool {
    manager: SharedSubAgentManager,
}

/// Tool to close a running sub-agent (alias for cancel).
pub struct AgentCloseTool {
    manager: SharedSubAgentManager,
}

impl AgentCloseTool {
    /// Create a new close tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager) -> Self {
        Self { manager }
    }
}

#[async_trait]
impl ToolSpec for AgentCloseTool {
    fn name(&self) -> &'static str {
        "close_agent"
    }

    fn description(&self) -> &'static str {
        "Close a running sub-agent. Alias for agent_cancel."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "id": {
                    "type": "string",
                    "description": "Agent id returned by agent_spawn"
                },
                "agent_id": {
                    "type": "string",
                    "description": "Alias for id"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![
            ToolCapability::ExecutesCode,
            ToolCapability::RequiresApproval,
        ]
    }

    fn approval_requirement(&self) -> ApprovalRequirement {
        ApprovalRequirement::Required
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let agent_id = input
            .get("id")
            .or_else(|| input.get("agent_id"))
            .and_then(|v| v.as_str())
            .ok_or_else(|| ToolError::missing_field("id"))?;
        let mut manager = self.manager.lock().await;
        let result = manager
            .cancel(agent_id)
            .map_err(|e| ToolError::execution_failed(format!("Failed to close sub-agent: {e}")))?;
        let tool_result =
            ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))?;
        Ok(wrap_with_deprecation_notice(
            tool_result,
            "close_agent",
            "agent_cancel",
        ))
    }
}

/// Tool to resume an existing sub-agent.
pub struct AgentResumeTool {
    manager: SharedSubAgentManager,
    runtime: SubAgentRuntime,
}

impl AgentResumeTool {
    /// Create a new resume tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, runtime: SubAgentRuntime) -> Self {
        Self { manager, runtime }
    }
}

#[async_trait]
impl ToolSpec for AgentResumeTool {
    fn name(&self) -> &'static str {
        "resume_agent"
    }

    fn description(&self) -> &'static str {
        "Resume a previously closed or completed sub-agent by restarting its assignment."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "id": {
                    "type": "string",
                    "description": "Agent id to resume"
                },
                "agent_id": {
                    "type": "string",
                    "description": "Alias for id"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![
            ToolCapability::ExecutesCode,
            ToolCapability::RequiresApproval,
        ]
    }

    fn approval_requirement(&self) -> ApprovalRequirement {
        ApprovalRequirement::Required
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let agent_id = input
            .get("id")
            .or_else(|| input.get("agent_id"))
            .and_then(|v| v.as_str())
            .ok_or_else(|| ToolError::missing_field("id"))?;
        let mut manager = self.manager.lock().await;
        let result = manager
            .resume(Arc::clone(&self.manager), self.runtime.clone(), agent_id)
            .map_err(|e| ToolError::execution_failed(format!("Failed to resume sub-agent: {e}")))?;
        ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))
    }
}

impl AgentListTool {
    /// Create a new list tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager) -> Self {
        Self { manager }
    }
}

#[async_trait]
impl ToolSpec for AgentListTool {
    fn name(&self) -> &'static str {
        "agent_list"
    }

    fn description(&self) -> &'static str {
        "List all active and recently completed sub-agents with their status, type, assignment, \
         steps taken, and duration."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {}
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![ToolCapability::ReadOnly]
    }

    async fn execute(
        &self,
        _input: Value,
        _context: &ToolContext,
    ) -> Result<ToolResult, ToolError> {
        let mut manager = self.manager.lock().await;
        manager.cleanup(COMPLETED_AGENT_RETENTION);
        let results = manager.list();
        ToolResult::json(&results).map_err(|e| ToolError::execution_failed(e.to_string()))
    }
}

/// Tool to send input to a running sub-agent.
pub struct AgentSendInputTool {
    manager: SharedSubAgentManager,
    name: &'static str,
}

impl AgentSendInputTool {
    /// Create a new send-input tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, name: &'static str) -> Self {
        Self { manager, name }
    }
}

#[async_trait]
impl ToolSpec for AgentSendInputTool {
    fn name(&self) -> &'static str {
        self.name
    }

    fn description(&self) -> &'static str {
        "Send input to a running sub-agent. Returns the agent's current snapshot after delivery."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "agent_id": {
                    "type": "string",
                    "description": "ID returned by agent_spawn"
                },
                "id": {
                    "type": "string",
                    "description": "Alias for agent_id"
                },
                "message": {
                    "type": "string",
                    "description": "Message to deliver to the agent"
                },
                "input": {
                    "type": "string",
                    "description": "Alias for message"
                },
                "items": {
                    "type": "array",
                    "description": "Structured input items (text, mention, skill, local_image, image)",
                    "items": {
                        "type": "object"
                    }
                },
                "interrupt": {
                    "type": "boolean",
                    "description": "Prioritize this message over pending inputs"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![]
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let agent_id = input
            .get("agent_id")
            .or_else(|| input.get("id"))
            .and_then(|v| v.as_str())
            .ok_or_else(|| ToolError::missing_field("agent_id"))?;
        let message = parse_text_or_items(&input, &["message", "input"], "items", "message")?;
        let interrupt = optional_bool(&input, "interrupt", false);

        let mut manager = self.manager.lock().await;
        manager
            .send_input(agent_id, message, interrupt)
            .map_err(|e| ToolError::execution_failed(e.to_string()))?;
        let snapshot = manager
            .get_result(agent_id)
            .map_err(|e| ToolError::execution_failed(e.to_string()))?;

        let tool_result =
            ToolResult::json(&snapshot).map_err(|e| ToolError::execution_failed(e.to_string()))?;
        // Annotate the alias name "send_input" with a deprecation notice;
        // the canonical name "agent_send_input" passes through unchanged.
        if self.name == "send_input" {
            Ok(wrap_with_deprecation_notice(
                tool_result,
                "send_input",
                "agent_send_input",
            ))
        } else {
            Ok(tool_result)
        }
    }
}

/// Tool to update assignment metadata for a sub-agent.
pub struct AgentAssignTool {
    manager: SharedSubAgentManager,
    name: &'static str,
}

impl AgentAssignTool {
    /// Create a new assignment tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, name: &'static str) -> Self {
        Self { manager, name }
    }
}

#[async_trait]
impl ToolSpec for AgentAssignTool {
    fn name(&self) -> &'static str {
        self.name
    }

    fn description(&self) -> &'static str {
        "Update a sub-agent's assignment (objective, role) and optionally deliver an immediate \
         coordinator note. The update is delivered as a high-priority message when `interrupt` is \
         true (the default). Returns the agent's current snapshot."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "agent_id": {
                    "type": "string",
                    "description": "Agent id returned by agent_spawn"
                },
                "id": {
                    "type": "string",
                    "description": "Alias for agent_id"
                },
                "objective": {
                    "type": "string",
                    "description": "Updated assignment objective"
                },
                "role": {
                    "type": "string",
                    "description": "Updated role alias: worker, explorer, awaiter, default"
                },
                "agent_role": {
                    "type": "string",
                    "description": "Alias for role"
                },
                "message": {
                    "type": "string",
                    "description": "Optional coordinator note to send to the agent"
                },
                "input": {
                    "type": "string",
                    "description": "Alias for message"
                },
                "items": {
                    "type": "array",
                    "description": "Structured input items (text, mention, skill, local_image, image)",
                    "items": {
                        "type": "object"
                    }
                },
                "interrupt": {
                    "type": "boolean",
                    "description": "Prioritize this assignment update in the agent inbox (default: true)"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![]
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let request = parse_assign_request(&input)?;
        let mut manager = self.manager.lock().await;
        let result = manager
            .assign(
                &request.agent_id,
                request.objective,
                request.role,
                request.message,
                request.interrupt,
            )
            .map_err(|e| ToolError::execution_failed(format!("Failed to assign sub-agent: {e}")))?;

        ToolResult::json(&result).map_err(|e| ToolError::execution_failed(e.to_string()))
    }
}

/// Tool to wait for sub-agents to complete.
pub struct AgentWaitTool {
    manager: SharedSubAgentManager,
    name: &'static str,
}

impl AgentWaitTool {
    /// Create a new wait tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, name: &'static str) -> Self {
        Self { manager, name }
    }
}

#[async_trait]
impl ToolSpec for AgentWaitTool {
    fn name(&self) -> &'static str {
        self.name
    }

    fn description(&self) -> &'static str {
        "Wait for one or more sub-agents to reach a terminal status. Use `wait_mode: \"all\"` to block \
         until every listed agent finishes, or `wait_mode: \"any\"` (default) to return as soon as \
         one finishes. When no ids are given, waits on all currently running sub-agents."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "ids": {
                    "type": "array",
                    "items": { "type": "string" },
                    "description": "Agent IDs to wait on. When omitted, waits on all currently running sub-agents."
                },
                "agent_ids": {
                    "type": "array",
                    "items": { "type": "string" },
                    "description": "Alias for ids"
                },
                "agent_id": {
                    "type": "string",
                    "description": "Single agent ID"
                },
                "id": {
                    "type": "string",
                    "description": "Alias for agent_id"
                },
                "wait_mode": {
                    "type": "string",
                    "description": "Wait behavior: any (default) or all"
                },
                "timeout_ms": {
                    "type": "integer",
                    "description": "Max wait time in milliseconds (default: 30000, clamped to 10000-3600000)"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![ToolCapability::ReadOnly]
    }

    async fn execute(&self, input: Value, _context: &ToolContext) -> Result<ToolResult, ToolError> {
        let timeout_ms = optional_u64(&input, "timeout_ms", DEFAULT_RESULT_TIMEOUT_MS)
            .clamp(MIN_WAIT_TIMEOUT_MS, MAX_RESULT_TIMEOUT_MS);
        let mut ids = parse_wait_ids(&input);
        if ids.is_empty() {
            let manager = self.manager.lock().await;
            ids = manager
                .list()
                .into_iter()
                .filter(|snapshot| snapshot.status == SubAgentStatus::Running)
                .map(|snapshot| snapshot.agent_id)
                .collect();
        }
        let wait_mode = parse_wait_mode(&input)?;

        if ids.is_empty() {
            let empty: Vec<SubAgentResult> = Vec::new();
            let mut result =
                ToolResult::json(&empty).map_err(|e| ToolError::execution_failed(e.to_string()))?;
            result.metadata = Some(json!({
                "wait_mode": wait_mode.as_str(),
                "timed_out": false,
                "status": "Completed",
                "timeout_ms": timeout_ms,
                "waited_ids": [],
                "completed_ids": [],
                "running_ids": [],
                "status_by_id": {}
            }));
            return Ok(result);
        }

        let waited_ids = ids.clone();

        let (snapshots, timed_out) = wait_for_agents(
            &self.manager,
            &ids,
            wait_mode,
            Duration::from_millis(timeout_ms),
        )
        .await?;

        let all_done = snapshots
            .iter()
            .all(|snapshot| snapshot.status != SubAgentStatus::Running);
        let completed_ids = snapshots
            .iter()
            .filter(|snapshot| snapshot.status != SubAgentStatus::Running)
            .map(|snapshot| snapshot.agent_id.clone())
            .collect::<Vec<_>>();
        let running_ids = snapshots
            .iter()
            .filter(|snapshot| snapshot.status == SubAgentStatus::Running)
            .map(|snapshot| snapshot.agent_id.clone())
            .collect::<Vec<_>>();
        let status_by_id = snapshots
            .iter()
            .map(|snapshot| {
                (
                    snapshot.agent_id.clone(),
                    subagent_status_name(&snapshot.status).to_string(),
                )
            })
            .collect::<HashMap<_, _>>();

        let mut result =
            ToolResult::json(&snapshots).map_err(|e| ToolError::execution_failed(e.to_string()))?;
        result.metadata = Some(json!({
            "wait_mode": wait_mode.as_str(),
            "timed_out": timed_out,
            "status": if timed_out { "TimedOut" } else if all_done { "Completed" } else { "Partial" },
            "timeout_ms": timeout_ms,
            "waited_ids": waited_ids,
            "completed_ids": completed_ids,
            "running_ids": running_ids,
            "status_by_id": status_by_id
        }));
        Ok(result)
    }
}

/// Tool to delegate a task to a specialized agent (alias for agent_spawn).
pub struct DelegateToAgentTool {
    manager: SharedSubAgentManager,
    runtime: SubAgentRuntime,
}

impl DelegateToAgentTool {
    /// Create a new delegation tool.
    #[must_use]
    pub fn new(manager: SharedSubAgentManager, runtime: SubAgentRuntime) -> Self {
        Self { manager, runtime }
    }
}

#[async_trait]
impl ToolSpec for DelegateToAgentTool {
    fn name(&self) -> &'static str {
        "delegate_to_agent"
    }

    fn description(&self) -> &'static str {
        "Delegate a task to a specialized sub-agent. This is an alias for agent_spawn — same schema, \
         same behavior. Use `type` (or `agent_name`, `agent_type`) to pick the agent flavor."
    }

    fn input_schema(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "agent_name": {
                    "type": "string",
                    "description": "Name/type alias for the agent (general, explore, plan, review, worker, explorer, awaiter)"
                },
                "type": {
                    "type": "string",
                    "description": "Alias for agent_name"
                },
                "agent_type": {
                    "type": "string",
                    "description": "Alias for agent_name"
                },
                "role": {
                    "type": "string",
                    "description": "Role alias: worker, explorer, awaiter, default"
                },
                "agent_role": {
                    "type": "string",
                    "description": "Alias for role"
                },
                "objective": {
                    "type": "string",
                    "description": "The goal or task description for the agent"
                },
                "prompt": {
                    "type": "string",
                    "description": "Alias for objective"
                },
                "message": {
                    "type": "string",
                    "description": "Alias for objective"
                },
                "items": {
                    "type": "array",
                    "description": "Structured input items (text, mention, skill, local_image, image)",
                    "items": {
                        "type": "object"
                    }
                },
                "allowed_tools": {
                    "type": "array",
                    "items": { "type": "string" },
                    "description": "Explicit tool allowlist (required for custom type)"
                }
            }
        })
    }

    fn capabilities(&self) -> Vec<ToolCapability> {
        vec![
            ToolCapability::ExecutesCode,
            ToolCapability::RequiresApproval,
        ]
    }

    fn approval_requirement(&self) -> ApprovalRequirement {
        ApprovalRequirement::Required
    }

    async fn execute(&self, input: Value, context: &ToolContext) -> Result<ToolResult, ToolError> {
        let spawn_tool = AgentSpawnTool::new(self.manager.clone(), self.runtime.clone());
        let result = spawn_tool.execute(input, context).await?;
        Ok(wrap_with_deprecation_notice(
            result,
            "delegate_to_agent",
            "agent_spawn",
        ))
    }
}

// === Sub-agent Execution ===

/// Build the system prompt for a sub-agent.
///
/// Starts with the per-type prompt (`SubAgentType::system_prompt`) and
/// appends a one-line role overlay when `assignment.role` is set. The
/// full role library — TOML overlays from `~/.deepseek/roles/`, the
/// `/roles` slash command, model overrides per role — lands in 0.6.7.
/// For 0.6.6 we just don't drop the role on the floor: the model sees
/// "You are operating in the role of `{name}`." as a final line so its
/// behavior reflects the user's choice.
fn build_subagent_system_prompt(
    agent_type: &SubAgentType,
    assignment: &SubAgentAssignment,
) -> String {
    let base = agent_type.system_prompt();
    match assignment.role.as_deref() {
        Some(role) if !role.trim().is_empty() => {
            format!(
                "{base}\n\nYou are operating in the role of `{}`.",
                role.trim()
            )
        }
        _ => base,
    }
}

struct SubAgentTask {
    manager_handle: SharedSubAgentManager,
    runtime: SubAgentRuntime,
    agent_id: String,
    agent_type: SubAgentType,
    prompt: String,
    assignment: SubAgentAssignment,
    /// `None` = full registry inheritance. `Some(list)` = explicit narrow.
    allowed_tools: Option<Vec<String>>,
    started_at: Instant,
    max_steps: u32,
    input_rx: mpsc::UnboundedReceiver<SubAgentInput>,
}

#[allow(clippy::too_many_lines)]
async fn run_subagent_task(task: SubAgentTask) {
    let result = run_subagent(
        &task.runtime,
        task.agent_id.clone(),
        task.agent_type,
        task.prompt,
        task.assignment,
        task.allowed_tools,
        task.started_at,
        task.max_steps,
        task.input_rx,
    )
    .await;

    let mut manager = task.manager_handle.lock().await;
    match &result {
        Ok(res) => manager.update_from_result(&task.agent_id, res.clone()),
        Err(err) => manager.update_failed(&task.agent_id, err.to_string()),
    }

    // Emit BOTH a human-friendly summary (rendered in the parent's
    // sidebar / cell) AND a structured sentinel the model can recognize
    // on its next turn. Format: human summary on the first line,
    // sentinel on the second. The sentinel uses an opaque tag
    // (`deepseek:subagent.done`) to avoid collision with normal user
    // text.
    let (summary, sentinel) = match &result {
        Ok(res) => (
            summarize_subagent_result(res),
            subagent_done_sentinel(&task.agent_id, res),
        ),
        Err(err) => (
            format!("Failed: {err}"),
            subagent_failed_sentinel(&task.agent_id, &err.to_string()),
        ),
    };

    if let Some(mb) = task.runtime.mailbox.as_ref() {
        let envelope = match &result {
            Ok(_) => MailboxMessage::Completed {
                agent_id: task.agent_id.clone(),
                summary: summary.clone(),
            },
            Err(err) => MailboxMessage::Failed {
                agent_id: task.agent_id.clone(),
                error: err.to_string(),
            },
        };
        let _ = mb.send(envelope);
    }

    if let Some(event_tx) = task.runtime.event_tx {
        let payload = format!("{summary}\n{sentinel}");
        let _ = event_tx.try_send(Event::AgentComplete {
            id: task.agent_id,
            result: payload,
        });
    }
}

/// Build a `<deepseek:subagent.done>` JSON sentinel for a successful child.
/// Intended to surface in the parent's transcript so the model recognizes
/// child completion and can decide whether to read the full result via
/// `agent_result`.
fn subagent_done_sentinel(agent_id: &str, res: &SubAgentResult) -> String {
    let payload = json!({
        "agent_id": agent_id,
        "agent_type": res.agent_type.as_str(),
        "status": subagent_status_name(&res.status),
        "duration_ms": res.duration_ms,
        "steps": res.steps_taken,
        "summary": summarize_subagent_result(res),
    });
    format!("<deepseek:subagent.done>{payload}</deepseek:subagent.done>")
}

/// Build a `<deepseek:subagent.done>` sentinel for a failed child.
fn subagent_failed_sentinel(agent_id: &str, err: &str) -> String {
    let payload = json!({
        "agent_id": agent_id,
        "status": "failed",
        "error": err,
    });
    format!("<deepseek:subagent.done>{payload}</deepseek:subagent.done>")
}

#[allow(clippy::too_many_arguments, clippy::too_many_lines)]
async fn run_subagent(
    runtime: &SubAgentRuntime,
    agent_id: String,
    agent_type: SubAgentType,
    prompt: String,
    assignment: SubAgentAssignment,
    allowed_tools: Option<Vec<String>>,
    started_at: Instant,
    max_steps: u32,
    mut input_rx: mpsc::UnboundedReceiver<SubAgentInput>,
) -> Result<SubAgentResult> {
    let system_prompt = build_subagent_system_prompt(&agent_type, &assignment);
    let tool_registry = SubAgentToolRegistry::new(
        runtime.clone(),
        allowed_tools.clone(),
        Arc::new(Mutex::new(TodoList::new())),
        Arc::new(Mutex::new(PlanState::default())),
    );
    let unavailable_tools = tool_registry.unavailable_allowed_tools();
    if !unavailable_tools.is_empty() {
        return Err(anyhow!(
            "Sub-agent requested unavailable tools: {}",
            unavailable_tools.join(", ")
        ));
    }
    let tools = tool_registry.tools_for_model();
    if let Some(mb) = runtime.mailbox.as_ref() {
        let _ = mb.send(MailboxMessage::started(&agent_id, agent_type.clone()));
    }
    emit_agent_progress(
        runtime.event_tx.as_ref(),
        runtime.mailbox.as_ref(),
        &agent_id,
        format!("started ({})", agent_type.as_str()),
    );

    let mut messages = vec![Message {
        role: "user".to_string(),
        content: vec![ContentBlock::Text {
            text: build_assignment_prompt(&prompt, &assignment, &agent_type),
            cache_control: None,
        }],
    }];

    let mut steps = 0;
    let mut final_result: Option<String> = None;
    let mut pending_inputs: VecDeque<SubAgentInput> = VecDeque::new();

    for _step in 0..max_steps {
        // Cooperative cancellation: bail if the parent (or root) cancelled
        // us while we were between steps. Children derive their token from
        // the parent's via `child_token()` so this propagates the whole tree.
        if runtime.cancel_token.is_cancelled() {
            emit_agent_progress(
                runtime.event_tx.as_ref(),
                runtime.mailbox.as_ref(),
                &agent_id,
                format!("step {steps}/{max_steps}: cancelled"),
            );
            if let Some(mb) = runtime.mailbox.as_ref() {
                let _ = mb.send(MailboxMessage::Cancelled {
                    agent_id: agent_id.clone(),
                });
            }
            return Ok(SubAgentResult {
                agent_id: agent_id.clone(),
                agent_type: agent_type.clone(),
                assignment: assignment.clone(),
                model: runtime.model.clone(),
                nickname: None,
                status: SubAgentStatus::Cancelled,
                result: None,
                steps_taken: steps,
                duration_ms: u64::try_from(started_at.elapsed().as_millis()).unwrap_or(u64::MAX),
            });
        }

        steps += 1;
        emit_agent_progress(
            runtime.event_tx.as_ref(),
            runtime.mailbox.as_ref(),
            &agent_id,
            format!("step {steps}/{max_steps}: requesting model response"),
        );

        while let Ok(input) = input_rx.try_recv() {
            if input.interrupt {
                pending_inputs.clear();
            }
            pending_inputs.push_back(input);
        }

        while let Some(input) = pending_inputs.pop_front() {
            if !input.text.trim().is_empty() {
                messages.push(Message {
                    role: "user".to_string(),
                    content: vec![ContentBlock::Text {
                        text: input.text,
                        cache_control: None,
                    }],
                });
            }
        }

        let request = MessageRequest {
            model: runtime.model.clone(),
            messages: messages.clone(),
            max_tokens: 4096,
            system: Some(SystemPrompt::Text(system_prompt.clone())),
            tools: Some(tools.clone()),
            tool_choice: Some(json!({ "type": "auto" })),
            metadata: None,
            thinking: None,
            reasoning_effort: None,
            stream: Some(false),
            temperature: None,
            top_p: None,
        };

        // Race the API call against the cancellation token so a parent
        // cancel during a long thinking turn doesn't have to wait for the
        // step timeout.
        let response = tokio::select! {
            biased;
            () = runtime.cancel_token.cancelled() => {
                emit_agent_progress(
                    runtime.event_tx.as_ref(),
                    runtime.mailbox.as_ref(),
                    &agent_id,
                    format!("step {steps}/{max_steps}: cancelled mid-request"),
                );
                if let Some(mb) = runtime.mailbox.as_ref() {
                    let _ = mb.send(MailboxMessage::Cancelled {
                        agent_id: agent_id.clone(),
                    });
                }
                return Ok(SubAgentResult {
                    agent_id: agent_id.clone(),
                    agent_type: agent_type.clone(),
                    assignment: assignment.clone(),
                    model: runtime.model.clone(),
                    nickname: None,
                    status: SubAgentStatus::Cancelled,
                    result: None,
                    steps_taken: steps,
                    duration_ms: u64::try_from(started_at.elapsed().as_millis())
                        .unwrap_or(u64::MAX),
                });
            }
            api = tokio::time::timeout(STEP_API_TIMEOUT, runtime.client.create_message(request)) => {
                api.map_err(|_| anyhow!("API call timed out after {}s", STEP_API_TIMEOUT.as_secs()))??
            }
        };

        let mut tool_uses = Vec::new();

        // Report token usage so the parent's cost counter updates live.
        if let Some(mb) = runtime.mailbox.as_ref() {
            let _ = mb.send(MailboxMessage::token_usage(
                &agent_id,
                response.model.clone(),
                response.usage.clone(),
            ));
        }

        for block in &response.content {
            match block {
                ContentBlock::Text { text, .. } if !text.trim().is_empty() => {
                    final_result = Some(text.clone());
                }
                ContentBlock::ToolUse {
                    id, name, input, ..
                } => {
                    tool_uses.push((id.clone(), name.clone(), input.clone()));
                }
                _ => {}
            }
        }

        messages.push(Message {
            role: "assistant".to_string(),
            content: response.content.clone(),
        });

        if tool_uses.is_empty() {
            while let Ok(input) = input_rx.try_recv() {
                if input.interrupt {
                    pending_inputs.clear();
                }
                pending_inputs.push_back(input);
            }
            if pending_inputs.is_empty() {
                emit_agent_progress(
                    runtime.event_tx.as_ref(),
                    runtime.mailbox.as_ref(),
                    &agent_id,
                    format!("step {steps}/{max_steps}: complete"),
                );
                break;
            }
            continue;
        }

        emit_agent_progress(
            runtime.event_tx.as_ref(),
            runtime.mailbox.as_ref(),
            &agent_id,
            format!(
                "step {steps}/{max_steps}: executing {} tool call(s)",
                tool_uses.len()
            ),
        );
        let mut tool_results: Vec<ContentBlock> = Vec::new();
        for (tool_id, tool_name, tool_input) in tool_uses {
            emit_agent_progress(
                runtime.event_tx.as_ref(),
                runtime.mailbox.as_ref(),
                &agent_id,
                format!("step {steps}/{max_steps}: running tool '{tool_name}'"),
            );
            if let Some(mb) = runtime.mailbox.as_ref() {
                let _ = mb.send(MailboxMessage::ToolCallStarted {
                    agent_id: agent_id.clone(),
                    tool_name: tool_name.clone(),
                    step: steps,
                });
            }
            let result = match tokio::time::timeout(TOOL_TIMEOUT, async {
                tool_registry
                    .execute(&agent_id, &tool_name, tool_input)
                    .await
            })
            .await
            {
                Ok(Ok(output)) => output,
                Ok(Err(e)) => format!("Error: {e}"),
                Err(_) => format!("Error: Tool {tool_name} timed out"),
            };
            let tool_ok = !result.starts_with("Error:");
            emit_agent_progress(
                runtime.event_tx.as_ref(),
                runtime.mailbox.as_ref(),
                &agent_id,
                format!("step {steps}/{max_steps}: finished tool '{tool_name}'"),
            );
            if let Some(mb) = runtime.mailbox.as_ref() {
                let _ = mb.send(MailboxMessage::ToolCallCompleted {
                    agent_id: agent_id.clone(),
                    tool_name: tool_name.clone(),
                    step: steps,
                    ok: tool_ok,
                });
            }

            tool_results.push(ContentBlock::ToolResult {
                tool_use_id: tool_id,
                content: result,
                is_error: None,
                content_blocks: None,
            });
        }

        if !tool_results.is_empty() {
            messages.push(Message {
                role: "user".to_string(),
                content: tool_results,
            });
        }
    }

    Ok(SubAgentResult {
        agent_id,
        agent_type,
        assignment,
        model: runtime.model.clone(),
        nickname: None,
        status: SubAgentStatus::Completed,
        result: final_result,
        steps_taken: steps,
        duration_ms: u64::try_from(started_at.elapsed().as_millis()).unwrap_or(u64::MAX),
    })
}

async fn wait_for_result(
    manager: &SharedSubAgentManager,
    agent_id: &str,
    timeout: Duration,
) -> Result<(SubAgentResult, bool), ToolError> {
    let deadline = Instant::now() + timeout;

    loop {
        let snapshot = {
            let manager = manager.lock().await;
            manager
                .get_result(agent_id)
                .map_err(|e| ToolError::execution_failed(e.to_string()))?
        };

        if snapshot.status != SubAgentStatus::Running {
            return Ok((snapshot, false));
        }
        if Instant::now() >= deadline {
            return Ok((snapshot, true));
        }

        tokio::time::sleep(RESULT_POLL_INTERVAL).await;
    }
}

async fn wait_for_agents(
    manager: &SharedSubAgentManager,
    ids: &[String],
    wait_mode: WaitMode,
    timeout: Duration,
) -> Result<(Vec<SubAgentResult>, bool), ToolError> {
    let deadline = Instant::now() + timeout;

    loop {
        let snapshots = {
            let manager = manager.lock().await;
            ids.iter()
                .map(|id| {
                    manager
                        .get_result(id)
                        .map_err(|e| ToolError::execution_failed(e.to_string()))
                })
                .collect::<Result<Vec<_>, _>>()?
        };

        if wait_mode.condition_met(&snapshots) {
            return Ok((snapshots, false));
        }
        if Instant::now() >= deadline {
            return Ok((snapshots, true));
        }

        tokio::time::sleep(RESULT_POLL_INTERVAL).await;
    }
}

fn parse_wait_mode(input: &Value) -> Result<WaitMode, ToolError> {
    let raw_mode = input
        .get("wait_mode")
        .and_then(|v| v.as_str())
        .unwrap_or("any");
    WaitMode::from_str(raw_mode).ok_or_else(|| {
        ToolError::invalid_input(format!("Invalid wait_mode '{raw_mode}'. Use: any or all"))
    })
}

fn parse_wait_ids(input: &Value) -> Vec<String> {
    let mut ids = Vec::new();
    for key in ["ids", "agent_ids"] {
        if let Some(list) = input.get(key).and_then(|v| v.as_array()) {
            for value in list {
                if let Some(id) = value.as_str() {
                    let id = id.trim();
                    if !id.is_empty() && !ids.iter().any(|existing| existing == id) {
                        ids.push(id.to_string());
                    }
                }
            }
        }
    }

    for key in ["agent_id", "id"] {
        if let Some(id) = input.get(key).and_then(|v| v.as_str()) {
            let id = id.trim();
            if !id.is_empty() && !ids.iter().any(|existing| existing == id) {
                ids.push(id.to_string());
            }
        }
    }

    ids
}

fn optional_input_str<'a>(input: &'a Value, keys: &[&str]) -> Option<&'a str> {
    keys.iter()
        .filter_map(|key| input.get(*key).and_then(Value::as_str))
        .map(str::trim)
        .find(|value| !value.is_empty())
}

fn parse_text_or_items(
    input: &Value,
    text_keys: &[&str],
    items_key: &str,
    required_field: &str,
) -> Result<String, ToolError> {
    let text = optional_input_str(input, text_keys).map(str::to_string);
    let items = parse_items_text(input, items_key)?;
    match (text, items) {
        (Some(_), Some(_)) => Err(ToolError::invalid_input(format!(
            "Provide either {required_field} text or {items_key}, but not both"
        ))),
        (Some(text), None) => Ok(text),
        (None, Some(items)) => Ok(items),
        (None, None) => Err(ToolError::missing_field(required_field)),
    }
}

fn parse_optional_text_or_items(
    input: &Value,
    text_keys: &[&str],
    items_key: &str,
) -> Result<Option<String>, ToolError> {
    let text = optional_input_str(input, text_keys).map(str::to_string);
    let items = parse_items_text(input, items_key)?;
    match (text, items) {
        (Some(_), Some(_)) => Err(ToolError::invalid_input(format!(
            "Provide either {} text or {}, but not both",
            text_keys[0], items_key
        ))),
        (Some(text), None) => Ok(Some(text)),
        (None, Some(items)) => Ok(Some(items)),
        (None, None) => Ok(None),
    }
}

fn parse_items_text(input: &Value, key: &str) -> Result<Option<String>, ToolError> {
    let Some(items) = input.get(key) else {
        return Ok(None);
    };
    let array = items
        .as_array()
        .ok_or_else(|| ToolError::invalid_input(format!("'{key}' must be an array")))?;
    if array.is_empty() {
        return Err(ToolError::invalid_input(format!("'{key}' cannot be empty")));
    }

    let mut lines = Vec::new();
    for item in array {
        let object = item
            .as_object()
            .ok_or_else(|| ToolError::invalid_input("each item must be an object"))?;
        let item_type = object
            .get("type")
            .and_then(Value::as_str)
            .unwrap_or("text")
            .trim();
        let rendered = match item_type {
            "text" => object
                .get("text")
                .and_then(Value::as_str)
                .map(str::trim)
                .filter(|text| !text.is_empty())
                .map(str::to_string)
                .ok_or_else(|| ToolError::invalid_input("text item requires non-empty text"))?,
            "mention" => {
                let name = object
                    .get("name")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("mention item requires name"))?;
                let path = object
                    .get("path")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("mention item requires path"))?;
                format!("[mention:${name}]({path})")
            }
            "skill" => {
                let name = object
                    .get("name")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("skill item requires name"))?;
                let path = object
                    .get("path")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("skill item requires path"))?;
                format!("[skill:${name}]({path})")
            }
            "local_image" => {
                let path = object
                    .get("path")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("local_image item requires path"))?;
                format!("[local_image:{path}]")
            }
            "image" => {
                let url = object
                    .get("image_url")
                    .and_then(Value::as_str)
                    .map(str::trim)
                    .filter(|text| !text.is_empty())
                    .ok_or_else(|| ToolError::invalid_input("image item requires image_url"))?;
                format!("[image:{url}]")
            }
            _ => object
                .get("text")
                .and_then(Value::as_str)
                .map(str::trim)
                .filter(|text| !text.is_empty())
                .map(str::to_string)
                .unwrap_or_else(|| "[input]".to_string()),
        };
        lines.push(rendered);
    }

    Ok(Some(lines.join("\n")))
}

fn parse_spawn_request(input: &Value) -> Result<SpawnRequest, ToolError> {
    let prompt = parse_text_or_items(
        input,
        &["prompt", "message", "objective"],
        "items",
        "prompt",
    )?;

    let type_input = optional_input_str(input, &["type", "agent_type", "agent_name"]);
    let role_input = optional_input_str(input, &["role", "agent_role"]);

    let parsed_type = type_input
        .map(|kind| {
            SubAgentType::from_str(kind).ok_or_else(|| {
                ToolError::invalid_input(format!(
                    "Invalid sub-agent type '{kind}'. Use: {VALID_SUBAGENT_TYPES}"
                ))
            })
        })
        .transpose()?;

    let parsed_role_type = role_input
        .map(|role| {
            SubAgentType::from_str(role).ok_or_else(|| {
                ToolError::invalid_input(format!(
                    "Invalid role alias '{role}'. Use: worker, explorer, awaiter, default"
                ))
            })
        })
        .transpose()?;

    if let (Some(type_kind), Some(role_kind)) = (&parsed_type, &parsed_role_type)
        && type_kind != role_kind
    {
        return Err(ToolError::invalid_input(
            "Conflicting type/agent_type and role/agent_role values".to_string(),
        ));
    }

    let agent_type = parsed_type
        .or(parsed_role_type)
        .unwrap_or(SubAgentType::General);

    if let Some(role) = role_input
        && normalize_role_alias(role).is_none()
    {
        return Err(ToolError::invalid_input(format!(
            "Invalid role alias '{role}'. Use: worker, explorer, awaiter, default"
        )));
    }

    let role = role_input
        .and_then(normalize_role_alias)
        .or_else(|| type_input.and_then(normalize_role_alias))
        .map(str::to_string);

    let allowed_tools = input
        .get("allowed_tools")
        .and_then(|v| v.as_array())
        .map(|items| {
            let mut tools = Vec::new();
            for item in items {
                if let Some(tool) = item.as_str() {
                    let trimmed = tool.trim();
                    if !trimmed.is_empty() && !tools.iter().any(|existing| existing == trimmed) {
                        tools.push(trimmed.to_string());
                    }
                }
            }
            tools
        });

    let cwd = parse_optional_cwd(input)?;
    let model = parse_optional_subagent_model(input, "model")?;

    Ok(SpawnRequest {
        prompt: prompt.clone(),
        agent_type,
        assignment: SubAgentAssignment::new(prompt, role),
        allowed_tools,
        model,
        cwd,
    })
}

pub(crate) fn normalize_requested_subagent_model(
    value: &str,
    field: &str,
) -> Result<String, ToolError> {
    let trimmed = value.trim();
    if trimmed.is_empty() {
        return Err(ToolError::invalid_input(format!("{field} cannot be blank")));
    }
    crate::config::normalize_model_name(trimmed).ok_or_else(|| {
        ToolError::invalid_input(format!(
            "Invalid {field} '{trimmed}'. Expected a DeepSeek model id such as deepseek-v4-pro or deepseek-v4-flash"
        ))
    })
}

pub(crate) fn configured_model_for_role_or_type(
    runtime: &SubAgentRuntime,
    role: Option<&str>,
    agent_type: &SubAgentType,
) -> Result<Option<String>, ToolError> {
    let mut keys = Vec::new();
    if let Some(role) = role.map(str::trim).filter(|role| !role.is_empty()) {
        keys.push(role.to_ascii_lowercase());
    }
    keys.push(agent_type.as_str().to_string());
    keys.push("default".to_string());

    for key in keys {
        if let Some(model) = runtime.role_models.get(&key) {
            return normalize_requested_subagent_model(model, &format!("subagents.{key}.model"))
                .map(Some);
        }
    }
    Ok(None)
}

fn parse_optional_subagent_model(input: &Value, key: &str) -> Result<Option<String>, ToolError> {
    match input.get(key) {
        None | Some(Value::Null) => Ok(None),
        Some(Value::String(value)) => normalize_requested_subagent_model(value, key).map(Some),
        Some(_) => Err(ToolError::invalid_input(format!("{key} must be a string"))),
    }
}

/// Extract an optional `cwd: String` from spawn input and convert to a
/// `PathBuf`. Empty / absent → `None`. Workspace-boundary check happens
/// at spawn time (the parent's workspace is known there, not here).
fn parse_optional_cwd(input: &Value) -> Result<Option<PathBuf>, ToolError> {
    let raw = input.get("cwd").and_then(|v| v.as_str()).map(str::trim);
    match raw {
        None | Some("") => Ok(None),
        Some(s) => Ok(Some(PathBuf::from(s))),
    }
}

fn parse_assign_request(input: &Value) -> Result<AssignRequest, ToolError> {
    let agent_id = input
        .get("agent_id")
        .or_else(|| input.get("id"))
        .and_then(Value::as_str)
        .map(str::trim)
        .filter(|id| !id.is_empty())
        .ok_or_else(|| ToolError::missing_field("agent_id"))?
        .to_string();
    let objective = optional_input_str(input, &["objective"]).map(str::to_string);
    let role = optional_input_str(input, &["role", "agent_role"])
        .map(|role| {
            normalize_role_alias(role).ok_or_else(|| {
                ToolError::invalid_input(format!(
                    "Invalid role alias '{role}'. Use: worker, explorer, awaiter, default"
                ))
            })
        })
        .transpose()?
        .map(str::to_string);
    let message = parse_optional_text_or_items(input, &["message", "input"], "items")?;
    let interrupt = optional_bool(input, "interrupt", true);

    if objective.is_none() && role.is_none() && message.is_none() {
        return Err(ToolError::invalid_input(
            "Provide at least one of objective, role/agent_role, message/input, or items"
                .to_string(),
        ));
    }

    Ok(AssignRequest {
        agent_id,
        objective,
        role,
        message,
        interrupt,
    })
}

fn normalize_role_alias(input: &str) -> Option<&'static str> {
    match input.to_ascii_lowercase().as_str() {
        "default" => Some("default"),
        "worker" | "general" => Some("worker"),
        "explorer" | "explore" => Some("explorer"),
        "awaiter" | "plan" | "planner" => Some("awaiter"),
        _ => None,
    }
}

fn build_assignment_prompt(
    prompt: &str,
    assignment: &SubAgentAssignment,
    agent_type: &SubAgentType,
) -> String {
    let role = assignment.role.as_deref().unwrap_or("default");
    format!(
        "Assignment metadata:\n- objective: {}\n- role: {}\n- resolved_type: {}\n\nTask:\n{}",
        assignment.objective,
        role,
        agent_type.as_str(),
        prompt
    )
}

fn emit_agent_progress(
    event_tx: Option<&mpsc::Sender<Event>>,
    mailbox: Option<&Mailbox>,
    agent_id: &str,
    status: String,
) {
    if let Some(mb) = mailbox {
        let _ = mb.send(MailboxMessage::progress(agent_id, status.clone()));
    }
    if let Some(event_tx) = event_tx {
        let _ = event_tx.try_send(Event::AgentProgress {
            id: agent_id.to_string(),
            status,
        });
    }
}

// === Tool Registry Helpers ===

/// Per-sub-agent tool registry.
///
/// Two modes:
/// - **Full inheritance** (`allowed_tools = None`): the child sees the same
///   tool surface as the parent's Agent mode — every tool family including
///   `with_subagent_tools` (so it can recurse). This is the v0.6.6 default.
/// - **Explicit narrow** (`allowed_tools = Some(list)`): legacy / Custom
///   path. The registry still builds the full surface, but only the listed
///   tool names are visible to the model and callable.
struct SubAgentToolRegistry {
    /// `None` → full inheritance (no filter applied). `Some(list)` →
    /// only the listed tools are visible to the model and callable.
    allowed_tools: Option<Vec<String>>,
    registry: ToolRegistry,
}

impl SubAgentToolRegistry {
    fn new(
        runtime: SubAgentRuntime,
        explicit_allowed_tools: Option<Vec<String>>,
        todo_list: SharedTodoList,
        plan_state: SharedPlanState,
    ) -> Self {
        // Build the full agent surface — same as the parent's Agent mode.
        // Children inherit shell, file, patch, search, web, git, diagnostics,
        // review, RLM, sub-agent management (so grandchildren can spawn),
        // plus per-child fresh todo/plan state.
        let context = runtime.context.clone();
        let registry = ToolRegistryBuilder::new()
            .with_full_agent_surface(
                Some(runtime.client.clone()),
                runtime.model.clone(),
                runtime.manager.clone(),
                runtime.clone(),
                runtime.allow_shell,
                todo_list,
                plan_state,
            )
            .build(context);

        Self {
            allowed_tools: explicit_allowed_tools,
            registry,
        }
    }

    /// Whether a given tool name is permitted under this child's filter.
    /// `None` filter = everything permitted.
    fn is_tool_allowed(&self, name: &str) -> bool {
        match &self.allowed_tools {
            None => true,
            Some(list) => list.iter().any(|t| t == name),
        }
    }

    fn tools_for_model(&self) -> Vec<Tool> {
        let api_tools = self.registry.to_api_tools();
        match &self.allowed_tools {
            None => api_tools,
            Some(list) => api_tools
                .into_iter()
                .filter(|tool| list.contains(&tool.name))
                .collect(),
        }
    }

    fn unavailable_allowed_tools(&self) -> Vec<String> {
        match &self.allowed_tools {
            None => Vec::new(),
            Some(list) => list
                .iter()
                .filter(|name| !self.registry.contains(name))
                .cloned()
                .collect(),
        }
    }

    async fn execute(&self, _agent_id: &str, name: &str, input: Value) -> Result<String> {
        if !self.is_tool_allowed(name) {
            return Err(anyhow!("Tool {name} not allowed for this sub-agent"));
        }
        self.registry
            .execute(name, input)
            .await
            .map_err(|e| anyhow!(e))
    }
}

/// Resolve the effective allowed-tools list for a child.
///
/// **v0.6.6 default: full inheritance.** Returning `Ok(None)` means the
/// child sees the same tool surface as the parent's Agent mode — every
/// family including `with_subagent_tools` so it can recurse. The narrowing
/// path (`Ok(Some(list))`) is only used by:
/// - `Custom` agent types (which require an explicit list).
/// - Callers that pass `explicit_tools` (advanced / legacy use).
///
/// `allow_shell = false` no longer narrows the tool LIST — the child's
/// registry simply doesn't register shell tools, which has the same
/// effect without papering over the parent's choice with a deny-list.
fn build_allowed_tools(
    agent_type: &SubAgentType,
    explicit_tools: Option<Vec<String>>,
    _allow_shell: bool,
) -> Result<Option<Vec<String>>> {
    if let Some(tools) = explicit_tools {
        let mut deduped = Vec::new();
        for tool in tools {
            let name = tool.trim();
            if !name.is_empty() && !deduped.iter().any(|existing: &String| existing == name) {
                deduped.push(name.to_string());
            }
        }
        if matches!(agent_type, SubAgentType::Custom) && deduped.is_empty() {
            return Err(anyhow!(
                "Custom sub-agent requires a non-empty allowed_tools list"
            ));
        }
        return Ok(Some(deduped));
    }

    if matches!(agent_type, SubAgentType::Custom) {
        return Err(anyhow!(
            "Custom sub-agent requires a non-empty allowed_tools list"
        ));
    }

    // Default: full registry inheritance from the parent. The child sees
    // every tool the parent has, including the sub-agent management family
    // (so it can recurse). Sandbox + workspace + depth cap remain the
    // safety net.
    Ok(None)
}

fn summarize_subagent_result(result: &SubAgentResult) -> String {
    match (&result.status, result.result.as_ref()) {
        (SubAgentStatus::Completed, Some(text)) => truncate_preview(text),
        (SubAgentStatus::Completed, None) => "Completed (no output)".to_string(),
        (SubAgentStatus::Interrupted(error), _) => format!("Interrupted: {error}"),
        (SubAgentStatus::Cancelled, _) => "Cancelled".to_string(),
        (SubAgentStatus::Failed(error), _) => format!("Failed: {error}"),
        (SubAgentStatus::Running, _) => "Running".to_string(),
    }
}

fn subagent_status_name(status: &SubAgentStatus) -> &'static str {
    match status {
        SubAgentStatus::Running => "running",
        SubAgentStatus::Completed => "completed",
        SubAgentStatus::Interrupted(_) => "interrupted",
        SubAgentStatus::Failed(_) => "failed",
        SubAgentStatus::Cancelled => "cancelled",
    }
}

fn truncate_preview(text: &str) -> String {
    const MAX_LEN: usize = 240;
    if text.len() <= MAX_LEN {
        text.to_string()
    } else {
        format!("{}...", text.chars().take(MAX_LEN).collect::<String>())
    }
}

// === System prompts ===
//
// Each per-agent-type prompt is composed from two parts:
//
//   1. A short role-specific intro that names the agent's job, its scope,
//      and any role-specific tactics or stop conditions.
//   2. The shared `subagent_output_format.md` block, which is the single
//      source of truth for the SUMMARY / EVIDENCE / CHANGES / RISKS /
//      BLOCKERS contract, the stop condition, and the typed-tool-surface
//      conventions. Tweaks to the contract live in that one file.
//
// `concat!` resolves at compile time, so the per-type constants remain
// `&'static str` and `system_prompt()` keeps its `String` return type.
// The `include_str!` calls inside each `concat!` all point at the same
// file, so the format is defined once even though it's inlined many times.

const GENERAL_AGENT_PROMPT: &str = concat!(
    "You are a general-purpose sub-agent spawned to handle a specific task autonomously.\n",
    "\n",
    "Your scope is exactly what the parent assigned to you. Do not expand the\n",
    "objective — if you discover related work that needs doing, surface it under\n",
    "RISKS or BLOCKERS rather than starting it. Work autonomously: the parent is\n",
    "not available to answer questions mid-run.\n",
    "\n",
    "Plan before you act. Use `checklist_write` for any multi-step task so your work\n",
    "is visible in the parent's sidebar. For complex initiatives, layer\n",
    "`update_plan` (strategy) above `checklist_write` (tactics).\n",
    "\n",
    include_str!("../../prompts/subagent_output_format.md"),
);

const EXPLORE_AGENT_PROMPT: &str = concat!(
    "You are an exploration sub-agent. Your job is to map the relevant region\n",
    "of the codebase fast and report what is there. You are read-only by\n",
    "convention — do not write, patch, or run side-effectful commands. If the\n",
    "task seems to require a write, stop and put it under BLOCKERS.\n",
    "\n",
    "Method:\n",
    "- Start with `list_dir` and `file_search` to orient.\n",
    "- Use `grep_files` (NOT `exec_shell rg`) to find call sites, type defs,\n",
    "  and string literals. Prefer narrow, structured queries over broad scans.\n",
    "- Read each candidate file with `read_file`. Skim, then quote line ranges.\n",
    "- Stop reading once you have enough evidence — exhaustive sweeps are not\n",
    "  the goal. The parent will spawn a follow-up explorer if needed.\n",
    "\n",
    "EVIDENCE is the load-bearing section for explorers. Cite every file you\n",
    "read with `path:line-range` and one line per finding. The parent uses your\n",
    "EVIDENCE list as a working set for the next turn, so be precise.\n",
    "\n",
    "CHANGES will almost always be \"None.\" for an explorer.\n",
    "\n",
    include_str!("../../prompts/subagent_output_format.md"),
);

const PLAN_AGENT_PROMPT: &str = concat!(
    "You are a planning sub-agent. Your job is to take an objective and\n",
    "produce a prioritized, executable plan — not to execute it. Keep writes\n",
    "to a minimum (notes and plan artifacts only); avoid patches and shell\n",
    "side effects.\n",
    "\n",
    "Method:\n",
    "- Read enough of the codebase to ground the plan in reality. A plan\n",
    "  written without `read_file` evidence is a guess.\n",
    "- Decompose the objective into ordered, verifiable steps. Each step names\n",
    "  the artifact it produces and the check that proves it works.\n",
    "- Surface trade-offs explicitly. If two approaches are viable, name both\n",
    "  and pick one with a reason — don't leave the parent with a fork.\n",
    "- Use `update_plan` to record the high-level strategy and `checklist_write` to\n",
    "  emit the granular backlog. The parent (and the user) reads these from\n",
    "  the sidebar after you finish.\n",
    "\n",
    "Prioritization: order todos by the dependency graph first, then by the\n",
    "ratio of risk reduced to effort spent. Tag each item with `[P0]` / `[P1]`\n",
    "/ `[P2]` so the parent can pick a slice without re-reading the whole plan.\n",
    "\n",
    "CHANGES should list the plan artifacts you wrote (e.g. `update_plan` rows,\n",
    "`checklist_write` ids, any notes). Do not include speculative future edits.\n",
    "\n",
    include_str!("../../prompts/subagent_output_format.md"),
);

const REVIEW_AGENT_PROMPT: &str = concat!(
    "You are a code review sub-agent. Your job is to read the code under\n",
    "review and emit a severity-scored list of findings. You are read-only by\n",
    "convention — do not patch the code under review even if a fix is obvious;\n",
    "describe the fix in the finding so the parent can apply it.\n",
    "\n",
    "Method:\n",
    "- Read the diff or files end-to-end with `read_file` before scoring.\n",
    "- Use `grep_files` to check for sibling call sites, similar patterns\n",
    "  elsewhere, and existing tests covering the same surface.\n",
    "- For each finding, score severity as one of:\n",
    "    BLOCKER  — correctness, security, data loss, or contract break.\n",
    "    MAJOR    — likely bug, missing error path, perf regression at scale.\n",
    "    MINOR    — style, naming, redundancy, suboptimal but correct code.\n",
    "    NIT      — taste; reasonable people may disagree.\n",
    "- Order EVIDENCE bullets by severity, BLOCKER first. Each bullet:\n",
    "  `[SEVERITY] path:line-range — one-line description; suggested fix`.\n",
    "- Be constructive. Cite the failure mode, not the author.\n",
    "\n",
    "If you find no issues at MAJOR or above, say so plainly in SUMMARY — a\n",
    "clean review is a valid result and the parent benefits from knowing it.\n",
    "\n",
    "CHANGES will almost always be \"None.\" for a reviewer.\n",
    "\n",
    include_str!("../../prompts/subagent_output_format.md"),
);

const CUSTOM_AGENT_PROMPT: &str = concat!(
    "You are a custom sub-agent. The parent has given you a narrowed tool\n",
    "registry — only the tools you see at runtime are available. Do not try\n",
    "to reach for a tool that is not registered; if the task needs one, put\n",
    "the gap under BLOCKERS and stop.\n",
    "\n",
    "Stay tightly scoped to the assigned objective. The parent chose Custom\n",
    "specifically to constrain you — do not expand into adjacent work.\n",
    "\n",
    include_str!("../../prompts/subagent_output_format.md"),
);

// === Tests ===

#[cfg(test)]
mod tests;
