//! Tool approval system for `DeepSeek` CLI
//!
//! Provides types and overlay widget for requesting user approval before
//! executing tools that may have costs or side effects.

use crate::pricing::CostEstimate;
use crate::sandbox::SandboxPolicy;
use crate::tui::views::{ModalKind, ModalView, ViewAction, ViewEvent};
use crate::tui::widgets::{ApprovalWidget, ElevationWidget, Renderable};
use crossterm::event::{KeyCode, KeyEvent};
use serde_json::Value;
use std::path::PathBuf;
use std::time::{Duration, Instant};

/// Determines when tool executions require user approval
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub enum ApprovalMode {
    /// Auto-approve all tools (YOLO mode / --yolo flag)
    Auto,
    /// Suggest approval for non-safe tools (non-YOLO modes)
    #[default]
    Suggest,
    /// Never execute tools requiring approval
    Never,
}

impl ApprovalMode {
    pub fn label(self) -> &'static str {
        match self {
            ApprovalMode::Auto => "AUTO",
            ApprovalMode::Suggest => "SUGGEST",
            ApprovalMode::Never => "NEVER",
        }
    }
}

/// User's decision for a pending approval
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ReviewDecision {
    /// Execute this tool once
    Approved,
    /// Approve and don't ask again for this tool type this session
    ApprovedForSession,
    /// Reject the tool execution
    Denied,
    /// Abort the entire turn
    Abort,
}

/// Categorizes tools by cost/risk level
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ToolCategory {
    /// Free, read-only operations (`list_dir`, `read_file`, todo_*)
    Safe,
    /// File modifications (`write_file`, `edit_file`)
    FileWrite,
    /// Shell execution (`exec_shell`)
    Shell,
}

/// Request for user approval of a tool execution
#[derive(Debug, Clone)]
pub struct ApprovalRequest {
    /// Unique ID for this tool use
    pub id: String,
    /// Tool being executed
    pub tool_name: String,
    /// Tool category
    pub category: ToolCategory,
    /// Tool parameters (for display)
    pub params: Value,
    /// Estimated cost (for paid tools)
    pub estimated_cost: Option<CostEstimate>,
}

impl ApprovalRequest {
    pub fn new(id: &str, tool_name: &str, params: &Value) -> Self {
        let category = get_tool_category(tool_name);
        let estimated_cost = crate::pricing::estimate_tool_cost(tool_name, params);

        Self {
            id: id.to_string(),
            tool_name: tool_name.to_string(),
            category,
            params: params.clone(),
            estimated_cost,
        }
    }

    /// Format parameters for display (truncated)
    pub fn params_display(&self) -> String {
        let truncated = truncate_params_value(&self.params, 200);
        serde_json::to_string(&truncated).unwrap_or_else(|_| truncated.to_string())
    }
}

/// Get the category for a tool by name
pub fn get_tool_category(name: &str) -> ToolCategory {
    if matches!(name, "write_file" | "edit_file" | "apply_patch") {
        ToolCategory::FileWrite
    } else if name == "exec_shell" {
        ToolCategory::Shell
    } else {
        // Default to safe (includes read/list/todo/note/update_plan and unknown tools)
        ToolCategory::Safe
    }
}

/// Approval overlay state managed by the modal view stack
#[derive(Debug, Clone)]
pub struct ApprovalView {
    request: ApprovalRequest,
    selected: usize,
    timeout: Option<Duration>,
    requested_at: Instant,
}

impl ApprovalView {
    pub fn new(request: ApprovalRequest) -> Self {
        Self {
            request,
            selected: 0,
            timeout: None,
            requested_at: Instant::now(),
        }
    }

    fn select_prev(&mut self) {
        self.selected = self.selected.saturating_sub(1);
    }

    fn select_next(&mut self) {
        self.selected = (self.selected + 1).min(3);
    }

    fn current_decision(&self) -> ReviewDecision {
        match self.selected {
            0 => ReviewDecision::Approved,
            1 => ReviewDecision::ApprovedForSession,
            2 => ReviewDecision::Denied,
            _ => ReviewDecision::Abort,
        }
    }

    fn emit_decision(&self, decision: ReviewDecision, timed_out: bool) -> ViewAction {
        ViewAction::EmitAndClose(ViewEvent::ApprovalDecision {
            tool_id: self.request.id.clone(),
            tool_name: self.request.tool_name.clone(),
            decision,
            timed_out,
        })
    }

    fn is_timed_out(&self) -> bool {
        match self.timeout {
            Some(timeout) => self.requested_at.elapsed() >= timeout,
            None => false,
        }
    }
}

impl ModalView for ApprovalView {
    fn kind(&self) -> ModalKind {
        ModalKind::Approval
    }

    fn handle_key(&mut self, key: KeyEvent) -> ViewAction {
        match key.code {
            KeyCode::Up | KeyCode::Char('k') => {
                self.select_prev();
                ViewAction::None
            }
            KeyCode::Down | KeyCode::Char('j') => {
                self.select_next();
                ViewAction::None
            }
            KeyCode::Enter => self.emit_decision(self.current_decision(), false),
            KeyCode::Char('y') => self.emit_decision(ReviewDecision::Approved, false),
            KeyCode::Char('a') => self.emit_decision(ReviewDecision::ApprovedForSession, false),
            KeyCode::Char('n') => self.emit_decision(ReviewDecision::Denied, false),
            KeyCode::Esc => self.emit_decision(ReviewDecision::Abort, false),
            _ => ViewAction::None,
        }
    }

    fn render(&self, area: ratatui::layout::Rect, buf: &mut ratatui::buffer::Buffer) {
        let approval_widget = ApprovalWidget::new(&self.request, self.selected);
        approval_widget.render(area, buf);
    }

    fn tick(&mut self) -> ViewAction {
        if self.is_timed_out() {
            return self.emit_decision(ReviewDecision::Denied, true);
        }
        ViewAction::None
    }
}

fn truncate_params_value(value: &Value, max_len: usize) -> Value {
    match value {
        Value::Object(map) => {
            let truncated = map
                .iter()
                .map(|(key, val)| (key.clone(), truncate_params_value(val, max_len)))
                .collect();
            Value::Object(truncated)
        }
        Value::Array(items) => {
            let truncated_items = items
                .iter()
                .map(|val| truncate_params_value(val, max_len))
                .collect();
            Value::Array(truncated_items)
        }
        Value::String(text) => Value::String(truncate_string_value(text, max_len)),
        other => {
            let rendered = other.to_string();
            if rendered.chars().count() > max_len {
                Value::String(truncate_string_value(&rendered, max_len))
            } else {
                other.clone()
            }
        }
    }
}

fn truncate_string_value(value: &str, max_len: usize) -> String {
    if value.chars().count() <= max_len {
        return value.to_string();
    }
    let truncated: String = value.chars().take(max_len).collect();
    format!("{truncated}...")
}

// ============================================================================
// Sandbox Elevation Flow
// ============================================================================

/// Options for elevating sandbox permissions after a denial.
#[derive(Debug, Clone, PartialEq, Eq)]
pub enum ElevationOption {
    /// Add network access to the sandbox policy.
    WithNetwork,
    /// Add write access to specific paths.
    WithWriteAccess(Vec<PathBuf>),
    /// Remove sandbox restrictions entirely (dangerous).
    FullAccess,
    /// Abort the tool execution.
    Abort,
}

impl ElevationOption {
    /// Get the display label for this option.
    pub fn label(&self) -> &'static str {
        match self {
            ElevationOption::WithNetwork => "Allow network access",
            ElevationOption::WithWriteAccess(_) => "Allow write access",
            ElevationOption::FullAccess => "Full access (no sandbox)",
            ElevationOption::Abort => "Abort",
        }
    }

    /// Get a short description.
    pub fn description(&self) -> &'static str {
        match self {
            ElevationOption::WithNetwork => "Retry with outbound network connections enabled",
            ElevationOption::WithWriteAccess(_) => "Retry with additional writable paths",
            ElevationOption::FullAccess => "Retry without any sandbox restrictions (dangerous!)",
            ElevationOption::Abort => "Cancel this tool execution",
        }
    }

    /// Convert to a sandbox policy.
    pub fn to_policy(&self, base_cwd: &PathBuf) -> SandboxPolicy {
        match self {
            ElevationOption::WithNetwork => SandboxPolicy::workspace_with_network(),
            ElevationOption::WithWriteAccess(paths) => {
                let mut roots = paths.clone();
                roots.push(base_cwd.clone());
                SandboxPolicy::workspace_with_roots(roots, false)
            }
            ElevationOption::FullAccess => SandboxPolicy::DangerFullAccess,
            ElevationOption::Abort => SandboxPolicy::default(), // Won't be used
        }
    }
}

/// Request for user decision after a sandbox denial.
#[derive(Debug, Clone)]
pub struct ElevationRequest {
    /// The tool ID that was blocked.
    pub tool_id: String,
    /// The tool name.
    pub tool_name: String,
    /// The command that was blocked (if shell).
    pub command: Option<String>,
    /// The reason for denial (from sandbox).
    pub denial_reason: String,
    /// Available elevation options.
    pub options: Vec<ElevationOption>,
}

impl ElevationRequest {
    /// Create a new elevation request for a shell command.
    pub fn for_shell(
        tool_id: &str,
        command: &str,
        denial_reason: &str,
        blocked_network: bool,
        blocked_write: bool,
    ) -> Self {
        let mut options = Vec::new();

        if blocked_network {
            options.push(ElevationOption::WithNetwork);
        }
        if blocked_write {
            options.push(ElevationOption::WithWriteAccess(vec![]));
        }
        options.push(ElevationOption::FullAccess);
        options.push(ElevationOption::Abort);

        Self {
            tool_id: tool_id.to_string(),
            tool_name: "exec_shell".to_string(),
            command: Some(command.to_string()),
            denial_reason: denial_reason.to_string(),
            options,
        }
    }

    /// Create a generic elevation request.
    #[allow(dead_code)]
    pub fn generic(tool_id: &str, tool_name: &str, denial_reason: &str) -> Self {
        Self {
            tool_id: tool_id.to_string(),
            tool_name: tool_name.to_string(),
            command: None,
            denial_reason: denial_reason.to_string(),
            options: vec![
                ElevationOption::WithNetwork,
                ElevationOption::FullAccess,
                ElevationOption::Abort,
            ],
        }
    }
}

/// Elevation overlay state managed by the modal view stack.
#[derive(Debug, Clone)]
pub struct ElevationView {
    request: ElevationRequest,
    selected: usize,
}

impl ElevationView {
    pub fn new(request: ElevationRequest) -> Self {
        Self {
            request,
            selected: 0,
        }
    }

    fn select_prev(&mut self) {
        self.selected = self.selected.saturating_sub(1);
    }

    fn select_next(&mut self) {
        let max = self.request.options.len().saturating_sub(1);
        self.selected = (self.selected + 1).min(max);
    }

    fn current_option(&self) -> &ElevationOption {
        &self.request.options[self.selected]
    }

    fn emit_decision(&self, option: ElevationOption) -> ViewAction {
        ViewAction::EmitAndClose(ViewEvent::ElevationDecision {
            tool_id: self.request.tool_id.clone(),
            tool_name: self.request.tool_name.clone(),
            option,
        })
    }

    /// Get the request for rendering.
    #[allow(dead_code)]
    pub fn request(&self) -> &ElevationRequest {
        &self.request
    }

    /// Get the currently selected index.
    #[allow(dead_code)]
    pub fn selected(&self) -> usize {
        self.selected
    }
}

impl ModalView for ElevationView {
    fn kind(&self) -> ModalKind {
        ModalKind::Elevation
    }

    fn handle_key(&mut self, key: KeyEvent) -> ViewAction {
        match key.code {
            KeyCode::Up | KeyCode::Char('k') => {
                self.select_prev();
                ViewAction::None
            }
            KeyCode::Down | KeyCode::Char('j') => {
                self.select_next();
                ViewAction::None
            }
            KeyCode::Enter => self.emit_decision(self.current_option().clone()),
            KeyCode::Char('n') => self.emit_decision(ElevationOption::WithNetwork),
            KeyCode::Char('w') => {
                // Find the write access option if available
                for opt in &self.request.options {
                    if matches!(opt, ElevationOption::WithWriteAccess(_)) {
                        return self.emit_decision(opt.clone());
                    }
                }
                ViewAction::None
            }
            KeyCode::Char('f') => self.emit_decision(ElevationOption::FullAccess),
            KeyCode::Esc | KeyCode::Char('a') => self.emit_decision(ElevationOption::Abort),
            _ => ViewAction::None,
        }
    }

    fn render(&self, area: ratatui::layout::Rect, buf: &mut ratatui::buffer::Buffer) {
        let elevation_widget = ElevationWidget::new(&self.request, self.selected);
        elevation_widget.render(area, buf);
    }
}
