use std::collections::HashMap;
use std::sync::Arc;

use algocline_core::pkg::{PkgType, TypeSource};
use algocline_core::QueryId;
use algocline_engine::{FeedResult, VariantPkg};

use super::alc_toml::load_alc_toml;
use super::eval_store::{splice_response_string, splice_response_warnings};
use super::resolve::{is_package_installed, make_require_code, resolve_code, QueryResponse};
use super::transcript::write_transcript_log;
use super::AppService;
use crate::pool::dispatch::{continue_via_pool, run_via_pool};

/// Recover from MCP clients that JSON-stringify an object-typed field
/// before sending. The MCP `inputSchema` for `ctx` / `opts` /
/// `strategy_opts` declares `type: object`, but some clients send a
/// JSON-encoded string instead. Without this normalisation the value
/// reaches Lua as a string and breaks pkgs that require a table
/// (issue 1778656404-63015).
///
/// Only `Value::String` payloads that parse into a JSON object or
/// array are replaced; ordinary strings and primitive scalars pass
/// through untouched.
pub(crate) fn normalize_stringified_json_object(v: serde_json::Value) -> serde_json::Value {
    match v {
        serde_json::Value::String(ref s) => match serde_json::from_str::<serde_json::Value>(s) {
            Ok(parsed @ serde_json::Value::Object(_)) => parsed,
            Ok(parsed @ serde_json::Value::Array(_)) => parsed,
            _ => v,
        },
        other => other,
    }
}

/// Splice `save_warning` into the JSON `result` when the optional
/// warning is `Some(_)`. Returns the original string unchanged when
/// there is no warning.
fn splice_save_warning(result_json: &str, warning: Option<String>) -> String {
    match warning {
        Some(msg) => splice_response_string(result_json, "save_warning", &msg),
        None => result_json.to_string(),
    }
}

/// Splice `transcript_warning` into the JSON `result` when the optional
/// warning is `Some(_)`. Returns the original string unchanged when
/// there is no warning.
fn splice_transcript_warning(result_json: &str, warning: Option<String>) -> String {
    match warning {
        Some(msg) => splice_response_string(result_json, "transcript_warning", &msg),
        None => result_json.to_string(),
    }
}

/// Build a frozen env snapshot from up to three sources and an optional allowlist.
///
/// # Sources (applied in priority order, lower overwritten by higher)
///
/// 1. **OS environment** (`ctx.env.allow_os = true` only) — `std::env::vars()` snapshot.
/// 2. **dotenv file** (`ctx.env.dotenv`) — parsed via `dotenvy`; keys overwrite OS layer.
/// 3. **inject** (`ctx.env.inject`) — explicit key/value map; highest priority, overwrites all.
///
/// # Arguments
///
/// - `ctx` — the full `alc_run` context value; `ctx["env"]` is extracted here.
/// - `project_root` — required when `ctx.env.dotenv` is a relative path.
///   `None` with a relative dotenv path is an error (avoids CWD ambiguity).
/// - `alc_toml_allow` — optional allowlist from `alc.toml [env].allow`.
///   When `Some`, the merged map is filtered to only keys present in the list.
///   `None` means no filtering (all resolved keys are kept).
///
/// # Errors
///
/// Returns `Err(String)` for:
/// - `ctx.env.inject` values that are not JSON strings
/// - `ctx.env.dotenv` is a relative path but `project_root` is `None`
/// - `dotenvy` I/O error opening the dotenv file
/// - `dotenvy` parse error for any entry in the dotenv file
pub(super) fn resolve_env(
    ctx: &serde_json::Value,
    project_root: Option<&std::path::Path>,
    alc_toml_allow: Option<&[String]>,
) -> Result<Arc<HashMap<String, String>>, String> {
    let env_obj = ctx.get("env").and_then(|v| v.as_object());

    // ── Layer 3 (highest): inject ──────────────────────────────────────────────
    let inject: HashMap<String, String> = if let Some(obj) = env_obj {
        if let Some(inject_val) = obj.get("inject") {
            match inject_val.as_object() {
                Some(m) => {
                    let mut map = HashMap::new();
                    for (k, v) in m {
                        match v.as_str() {
                            Some(s) => {
                                map.insert(k.clone(), s.to_string());
                            }
                            None => {
                                return Err(format!(
                                    "ctx.env.inject: value for key '{k}' must be a string, got {v}"
                                ));
                            }
                        }
                    }
                    map
                }
                None => {
                    return Err(format!(
                        "ctx.env.inject must be an object, got {}",
                        inject_val
                    ));
                }
            }
        } else {
            HashMap::new()
        }
    } else {
        HashMap::new()
    };

    // Resolved dotenv path (if any)
    let dotenv_path: Option<std::path::PathBuf> = if let Some(p) = env_obj
        .and_then(|o| o.get("dotenv"))
        .and_then(|v| v.as_str())
    {
        let path = std::path::Path::new(p);
        if path.is_absolute() {
            Some(path.to_path_buf())
        } else {
            match project_root {
                Some(root) => Some(root.join(p)),
                None => {
                    return Err(format!(
                        "ctx.env.dotenv: relative path '{p}' requires project_root to be set"
                    ));
                }
            }
        }
    } else {
        None
    };

    let allow_os = env_obj
        .and_then(|o| o.get("allow_os"))
        .and_then(|v| v.as_bool())
        .unwrap_or(false);

    let mut merged: HashMap<String, String> = HashMap::new();

    // ── Layer 1 (lowest): OS environment ──────────────────────────────────────
    if allow_os {
        for (k, v) in std::env::vars() {
            merged.insert(k, v);
        }
    }

    // ── Layer 2: dotenv file ───────────────────────────────────────────────────
    if let Some(ref full) = dotenv_path {
        let iter = dotenvy::from_path_iter(full)
            .map_err(|e| format!("ctx.env.dotenv: failed to open '{}': {e}", full.display()))?;
        for item in iter {
            let (k, v) = item
                .map_err(|e| format!("ctx.env.dotenv: parse error in '{}': {e}", full.display()))?;
            merged.insert(k, v);
        }
    }

    // ── Layer 3: inject (overwrite, highest priority) ──────────────────────────
    for (k, v) in inject {
        merged.insert(k, v);
    }

    // ── Optional allowlist filter (alc.toml [env].allow) ──────────────────────
    if let Some(allow) = alc_toml_allow {
        if !allow.is_empty() {
            let allowset: std::collections::HashSet<&String> = allow.iter().collect();
            merged.retain(|k, _| allowset.contains(k));
        }
    }

    Ok(Arc::new(merged))
}

impl AppService {
    /// Execute Lua code with optional JSON context.
    ///
    /// When `host_mode: Some(true)` is passed, the call is proxied via
    /// `PoolClient` to a long-lived worker subprocess over a Unix domain socket.
    /// When `host_mode` is `None` or `Some(false)` the existing in-process
    /// `Executor::start_session` path is used unchanged.
    ///
    /// # Concurrency
    ///
    /// **host_mode=false (default)**: No additional locking beyond `SessionRegistry`
    /// lock C. `AppService` itself holds no long-lived lock during this call.
    ///
    /// **host_mode=true**: Acquires `RwLock<PoolRegistry>` (write) and advisory
    /// `fs4::FileExt::lock_exclusive` to update `registry.json`. These locks are
    /// **not** held across the UDS round-trip await.
    ///
    /// **Cancel safety**: cancelling this `.await` mid-UDS-request leaves the
    /// worker subprocess running. The registry entry persists; callers can
    /// reconnect via `alc_continue` after MCP restart.
    pub async fn run(
        &self,
        code: Option<String>,
        code_file: Option<String>,
        ctx: Option<serde_json::Value>,
        project_root: Option<String>,
        host_mode: Option<bool>,
    ) -> Result<String, String> {
        let code = resolve_code(code, code_file)?;
        let ctx = normalize_stringified_json_object(ctx.unwrap_or(serde_json::Value::Null));
        let (extra, extra_warnings) = self.resolve_extra_lib_paths(project_root.as_deref());
        let (variants, variant_warnings) = self.resolve_variant_pkgs(project_root.as_deref());
        let mut warnings: Vec<String> = extra_warnings;
        warnings.extend(variant_warnings);

        if host_mode == Some(true) {
            // ── Pool path (Crux: MCP thin proxy IPC boundary) ─────────────────
            // Worker subprocess is spawned and communicated via UDS.
            // SessionRegistry (in-memory) is NOT touched on this path.
            let (session_id, json, pool_save_error) = run_via_pool(
                &self.pool_dir,
                &self.pool_reg_path,
                &self.pool_lock_path,
                extra,
                code,
                ctx,
            )
            .await
            .map_err(|e| e.to_string())?;

            // session_id is stored in the JSON by the worker; update the
            // in-memory registry so this MCP instance can route continues
            // without another disk read.
            // Load the just-persisted entry from disk to keep in-memory
            // registry in sync.  This is a best-effort convenience cache;
            // the disk state is authoritative.  Failure is surfaced to the
            // MCP wire response as `pool_cache_reload_warning` so the caller
            // can observe stale-cache conditions; tracing::warn! is kept for
            // operator visibility in logs.
            let cache_reload_warning: Option<String> =
                match crate::pool::PoolRegistry::load_or_default(&self.pool_reg_path) {
                    Ok(reg) => {
                        let mut guard = self.pool_registry.write().await;
                        *guard = reg;
                        None
                    }
                    Err(e) => {
                        tracing::warn!(
                            error = %e,
                            "failed to reload pool registry after run; in-memory cache may be stale"
                        );
                        Some(e.to_string())
                    }
                };

            let json = splice_response_warnings(&json, "lib_path_warnings", &warnings);
            let json = match pool_save_error {
                Some(msg) => splice_response_string(&json, "pool_save_error", &msg),
                None => json,
            };
            let json = match cache_reload_warning {
                Some(msg) => splice_response_string(&json, "pool_cache_reload_warning", &msg),
                None => json,
            };
            let _ = session_id; // session_id is embedded in the JSON response
            return Ok(json);
        }

        // ── In-process path (default) ──────────────────────────────────────────

        // Build the frozen env snapshot at alc_run invocation time (TIME boundary).
        // Load alc.toml to get the optional env.allow allowlist.
        let alc_toml_allow_list: Vec<String> = if let Some(root) = project_root.as_deref() {
            let root_path = std::path::Path::new(root);
            match load_alc_toml(root_path) {
                Ok(Some(t)) => t.env.map(|e| e.allow).unwrap_or_default(),
                Ok(None) => Vec::new(),
                Err(e) => return Err(format!("alc.toml load error: {e}")),
            }
        } else {
            Vec::new()
        };
        let alc_toml_allow = if alc_toml_allow_list.is_empty() {
            None
        } else {
            Some(alc_toml_allow_list.as_slice())
        };

        let project_root_path = project_root.as_deref().map(std::path::Path::new);
        let env_map = resolve_env(&ctx, project_root_path, alc_toml_allow)?;

        let json = self
            .start_and_tick(env_map, code, ctx, None, extra, variants)
            .await?;
        Ok(splice_response_warnings(
            &json,
            "lib_path_warnings",
            &warnings,
        ))
    }

    /// Apply a built-in strategy to a task.
    ///
    /// If the requested package is not installed, automatically installs the
    /// bundled package collection from GitHub before executing.
    ///
    /// `project_root` — optional absolute path to the project root containing
    /// `alc.lock`. Falls back to `ALC_PROJECT_ROOT` env or ancestor walk.
    pub async fn advice(
        &self,
        strategy: &str,
        task: Option<String>,
        opts: Option<serde_json::Value>,
        project_root: Option<String>,
    ) -> Result<String, String> {
        // Auto-install bundled packages if the requested strategy is missing
        let app_dir = self.log_config.app_dir();
        if !is_package_installed(&app_dir, strategy) {
            self.auto_install_bundled_packages().await?;
            if !is_package_installed(&app_dir, strategy) {
                return Err(format!(
                    "Package '{strategy}' not found after installing bundled collection. \
                     Use alc_pkg_install to install it manually."
                ));
            }
        }

        // Guard: reject library packages before make_require_code (= M.run invocation)
        if let Some((PkgType::Library, _)) = self.resolve_pkg_type_lua(strategy).await? {
            return Err(format!(
                "Package '{strategy}' is a library package (type = \"library\"). \
                 Library packages provide reusable modules and do not have a run() entry point. \
                 Use alc_run with custom code to import this library."
            ));
        }

        let code = make_require_code(strategy);

        let opts = opts.map(normalize_stringified_json_object);
        let mut ctx_map = match opts {
            Some(serde_json::Value::Object(m)) => m,
            _ => serde_json::Map::new(),
        };
        if let Some(task) = task {
            ctx_map.insert("task".into(), serde_json::Value::String(task));
        }
        let ctx = serde_json::Value::Object(ctx_map);

        let (extra, extra_warnings) = self.resolve_extra_lib_paths(project_root.as_deref());
        let (variants, variant_warnings) = self.resolve_variant_pkgs(project_root.as_deref());
        let mut warnings: Vec<String> = extra_warnings;
        warnings.extend(variant_warnings);
        // advice() does not accept ctx.env; pass an empty map so AlcEnv is
        // present but empty (no env vars visible to advice strategies).
        let env_map = Arc::new(HashMap::new());
        let json = self
            .start_and_tick(env_map, code, ctx, Some(strategy), extra, variants)
            .await?;
        Ok(splice_response_warnings(
            &json,
            "lib_path_warnings",
            &warnings,
        ))
    }

    /// Resolve the package type and provenance via Lua VM (`eval_simple`).
    ///
    /// # Returns
    ///
    /// - `Ok(Some((PkgType, TypeSource)))` — type and provenance both parsed
    ///   successfully.
    /// - `Ok(None)` — eval succeeded but either the `type` or `type_source`
    ///   field could not be parsed (unknown value or absent field); the caller
    ///   treats this as a legacy passthrough and does not apply the library
    ///   guard.
    /// - `Err(String)` — `eval_simple` failed; propagated to the caller.
    ///
    /// # Provenance
    ///
    /// The Lua snippet (`LUA_TYPE_AUTODETECT`) sets `meta.type_source` to one
    /// of `"auto_detected_runnable"` / `"auto_detected_library"` before control
    /// returns to Rust, so both fields are always populated when the snippet
    /// runs without error.
    pub(crate) async fn resolve_pkg_type_lua(
        &self,
        name: &str,
    ) -> Result<Option<(PkgType, TypeSource)>, String> {
        let auto = super::resolve::LUA_TYPE_AUTODETECT;
        let code = format!(
            r#"package.loaded["{name}"] = nil; local pkg = require("{name}"); local meta = pkg.meta or {{}}; {auto}; return {{ type = meta.type, type_source = meta.type_source }}"#,
            name = name,
            auto = auto,
        );
        let val = self.executor.eval_simple(code).await?;
        let result = val.as_object().and_then(|obj| {
            let pkg_type =
                obj.get("type")
                    .and_then(|v| v.as_str())
                    .and_then(|s| match s.parse::<PkgType>() {
                        Ok(t) => Some(t),
                        Err(e) => {
                            tracing::warn!(
                                package = name,
                                raw_type = s,
                                error = %e,
                                "unknown pkg type string; treating as legacy passthrough"
                            );
                            None
                        }
                    });
            let type_source = obj
                .get("type_source")
                .and_then(|v| v.as_str())
                .and_then(|s| s.parse::<TypeSource>().ok());
            match (pkg_type, type_source) {
                (Some(t), Some(src)) => Some((t, src)),
                _ => None,
            }
        });
        Ok(result)
    }

    /// Continue a paused execution — batch feed.
    ///
    /// For pool sessions (`session_id` found in registry.json), each response
    /// in the batch is forwarded to the worker via `PoolClient::send_request`.
    /// For in-MCP sessions, the existing `SessionRegistry::feed_response` path
    /// is used unchanged.
    pub async fn continue_batch(
        &self,
        session_id: &str,
        responses: Vec<QueryResponse>,
    ) -> Result<String, String> {
        // ── Pool path check (same registry lookup as continue_single) ─────────
        let pool_entry = {
            let reg = self.pool_registry.read().await;
            reg.find(session_id).cloned()
        };

        let pool_entry = if pool_entry.is_some() {
            pool_entry
        } else {
            match crate::pool::PoolRegistry::load_or_default(&self.pool_reg_path) {
                Ok(reg) => {
                    let entry = reg.find(session_id).cloned();
                    if entry.is_some() {
                        let mut guard = self.pool_registry.write().await;
                        *guard = reg;
                    }
                    entry
                }
                Err(e) => {
                    return Err(format!("Continue failed: {e}"));
                }
            }
        };

        if let Some(entry) = pool_entry {
            // ── Pool routing ────────────────────────────────────────────────────
            let mut last_json = None;
            for qr in responses {
                let json =
                    continue_via_pool(&entry, session_id, qr.response, Some(qr.query_id), qr.usage)
                        .await
                        .map_err(|e| format!("Continue failed: {e}"))?;
                last_json = Some(json);
            }
            return last_json.ok_or_else(|| "Empty responses array".to_string());
        }

        // ── In-MCP path ────────────────────────────────────────────────────────
        let mut last_result = None;
        for qr in responses {
            let qid = QueryId::parse(&qr.query_id);
            let result = self
                .registry
                .feed_response(session_id, &qid, qr.response, qr.usage.as_ref())
                .await
                .map_err(|e| format!("Continue failed: {e}"))?;
            last_result = Some(result);
        }
        let result = last_result.ok_or("Empty responses array")?;
        let transcript_warning = self.maybe_log_transcript(&result, session_id);
        let json = result.to_json(session_id).to_string();
        let json = splice_transcript_warning(&json, transcript_warning);
        let save_warning = self.maybe_save_eval(&result, session_id, &json);
        Ok(splice_save_warning(&json, save_warning))
    }

    /// Continue a paused execution — single response (with optional query_id).
    ///
    /// Routing is automatic: if `session_id` is found in `registry.json`
    /// (pool path), the call is proxied via `PoolClient` over UDS. If not
    /// found (in-MCP path), the existing `SessionRegistry::feed_response`
    /// is used. Both paths never coexist for the same `session_id`.
    ///
    /// # Concurrency
    ///
    /// **Pool path**: acquires `RwLock<PoolRegistry>` (read) to look up the
    /// session entry, then acquires `tokio::sync::Mutex` inside `PoolClient`
    /// to serialize the UDS write. Neither lock is held across the UDS await.
    ///
    /// **In-MCP path**: acquires lock C in the two-phase pattern documented on
    /// `SessionRegistry::feed_response`.
    ///
    /// **Cancel safety**: cancelling mid-await on the pool path leaves the
    /// worker subprocess running (UDS send may have been partially written;
    /// `read_line` is not cancel-safe — a partial line in the buffer renders
    /// the connection unusable and `PoolClient` must reconnect).
    pub async fn continue_single(
        &self,
        session_id: &str,
        response: String,
        query_id: Option<&str>,
        usage: Option<algocline_core::TokenUsage>,
    ) -> Result<String, String> {
        // ── Pool path: check in-memory registry, then disk registry ───────────
        // K-4: acquire read lock, clone the entry, release lock BEFORE await.
        let pool_entry = {
            let reg = self.pool_registry.read().await;
            reg.find(session_id).cloned()
        }; // read lock released here

        // If in-memory cache missed, check disk (e.g. after MCP restart).
        let pool_entry = if pool_entry.is_some() {
            pool_entry
        } else {
            match crate::pool::PoolRegistry::load_or_default(&self.pool_reg_path) {
                Ok(reg) => {
                    let entry = reg.find(session_id).cloned();
                    if entry.is_some() {
                        // Warm the in-memory cache.
                        let mut guard = self.pool_registry.write().await;
                        *guard = reg;
                    }
                    entry
                }
                Err(e) => {
                    // Corrupt registry: propagate to MCP wire per §Error 伝播規律.
                    return Err(format!("Continue failed: {e}"));
                }
            }
        };

        if let Some(entry) = pool_entry {
            // ── Pool routing (Crux: MCP thin proxy IPC boundary) ──────────────
            let json = continue_via_pool(
                &entry,
                session_id,
                response,
                query_id.map(str::to_string),
                usage,
            )
            .await
            .map_err(|e| format!("Continue failed: {e}"))?;
            return Ok(json);
        }

        // ── In-MCP path ────────────────────────────────────────────────────────
        let query_id = match query_id {
            Some(qid) => QueryId::parse(qid),
            None => self
                .registry
                .resolve_sole_pending_id(session_id)
                .await
                .map_err(|e| format!("Continue failed: {e}"))?,
        };

        let result = self
            .registry
            .feed_response(session_id, &query_id, response, usage.as_ref())
            .await
            .map_err(|e| format!("Continue failed: {e}"))?;

        let transcript_warning = self.maybe_log_transcript(&result, session_id);
        let json = result.to_json(session_id).to_string();
        let json = splice_transcript_warning(&json, transcript_warning);
        let save_warning = self.maybe_save_eval(&result, session_id, &json);
        Ok(splice_save_warning(&json, save_warning))
    }

    // ─── Internal ───────────────────────────────────────────────

    pub(super) fn maybe_log_transcript(
        &self,
        result: &FeedResult,
        session_id: &str,
    ) -> Option<String> {
        if let FeedResult::Finished(exec_result) = result {
            // Mutex poison means a previous thread panicked while holding the lock.
            // Strategy name is non-critical for correctness, but the failure must be
            // surfaced to MCP callers so it is observable, not silently dropped.
            // See CLAUDE.md §Service 層の Error 伝播規律.
            let strategy = match self.session_strategies.lock() {
                Ok(mut map) => map.remove(session_id),
                Err(e) => {
                    tracing::warn!(
                        "session_strategies mutex poisoned for '{}': {}",
                        session_id,
                        e
                    );
                    // Return warning immediately; transcript cannot be written
                    // without strategy context being reliably recoverable.
                    return Some(format!(
                        "session_strategies mutex poisoned for '{session_id}': {e}"
                    ));
                }
            };
            // write_transcript_log returns Ok(Some(warning)) when meta write
            // failed but the main log succeeded, so both Err and meta warning
            // are surfaced as transcript_warning on the wire response.
            match write_transcript_log(
                &self.log_config,
                session_id,
                &exec_result.metrics,
                strategy.as_deref(),
            ) {
                Err(e) => Some(e.to_string()),
                Ok(meta_warning) => meta_warning,
            }
        } else {
            None
        }
    }

    /// Persist eval result for a finished session, returning any storage
    /// failure as `Some(msg)` so the caller can surface it on the wire
    /// response. `None` covers both "not an eval session" and
    /// "successfully saved" — they are indistinguishable to the caller
    /// because both produce the same wire shape.
    pub(super) fn maybe_save_eval(
        &self,
        result: &FeedResult,
        session_id: &str,
        result_json: &str,
    ) -> Option<String> {
        if !matches!(result, FeedResult::Finished(_)) {
            return None;
        }
        let strategy = {
            let mut map = self.eval_sessions.lock().unwrap_or_else(|e| e.into_inner());
            map.remove(session_id)
        };
        strategy.and_then(|s| {
            super::eval_store::save_eval_result(&self.log_config.app_dir(), &s, result_json).err()
        })
    }

    /// Start a Lua session with the given env snapshot and tick until the first
    /// pause or completion.
    ///
    /// # Arguments
    ///
    /// - `env_map` — frozen env snapshot built by `resolve_env`; passed to
    ///   `executor.start_session_with_env` so `alc.env` is populated before any
    ///   Lua code runs (TIME boundary: snapshot is taken before this call).
    /// - `code` — Lua source to execute.
    /// - `ctx` — JSON context accessible as `ctx` global in the Lua VM.
    /// - `strategy` — optional strategy name (used to correlate eval sessions).
    /// - `extra_lib_paths` — additional `require` search paths.
    /// - `variant_pkgs` — variant package overrides.
    ///
    /// # Errors
    ///
    /// Returns `Err(String)` if session spawn or initial execution fails.
    pub(super) async fn start_and_tick(
        &self,
        env_map: Arc<HashMap<String, String>>,
        code: String,
        ctx: serde_json::Value,
        strategy: Option<&str>,
        extra_lib_paths: Vec<std::path::PathBuf>,
        variant_pkgs: Vec<VariantPkg>,
    ) -> Result<String, String> {
        let scenarios_dir = self.log_config.app_dir().scenarios_dir();
        let session = self
            .executor
            .start_session_with_env(
                env_map,
                code,
                ctx,
                extra_lib_paths,
                variant_pkgs,
                Arc::clone(&self.state_store),
                Arc::clone(&self.card_store),
                scenarios_dir,
            )
            .await?;
        let (session_id, result) = self
            .registry
            .start_execution(session)
            .await
            .map_err(|e| format!("Execution failed: {e}"))?;
        if let Some(s) = strategy {
            if let Ok(mut map) = self.session_strategies.lock() {
                map.insert(session_id.clone(), s.to_string());
            }
        }
        let transcript_warning = self.maybe_log_transcript(&result, &session_id);
        let json = result.to_json(&session_id).to_string();
        Ok(splice_transcript_warning(&json, transcript_warning))
    }
}

#[cfg(test)]
mod tests {
    use std::path::PathBuf;
    use std::sync::Arc;

    use algocline_core::{
        AppDir, ExecutionMetrics, ExecutionObserver, LlmQuery, QueryId, TerminalState,
    };
    use algocline_engine::{ExecutionResult, FeedResult};

    use super::super::config::{AppConfig, LogDirSource};
    use super::{splice_transcript_warning, AppService};

    fn make_metrics_with_transcript() -> ExecutionMetrics {
        let metrics = ExecutionMetrics::new();
        let observer = metrics.create_observer();
        observer.on_paused(&[LlmQuery {
            id: QueryId::single(),
            prompt: "test prompt".into(),
            system: None,
            max_tokens: 100,
            grounded: false,
            underspecified: false,
        }]);
        metrics
    }

    fn make_finished_result(metrics: ExecutionMetrics) -> FeedResult {
        FeedResult::Finished(ExecutionResult {
            state: TerminalState::Completed {
                result: serde_json::json!({"ok": true}),
            },
            metrics,
        })
    }

    /// Build a minimal AppService with log_enabled and a custom log_dir.
    async fn make_app_service_with_log_dir(log_dir: PathBuf) -> AppService {
        let executor = Arc::new(
            algocline_engine::Executor::new(vec![])
                .await
                .expect("executor"),
        );
        let tmp_app = tempfile::tempdir().expect("test tempdir");
        let log_config = AppConfig {
            log_dir: Some(log_dir),
            log_dir_source: LogDirSource::EnvVar,
            log_enabled: true,
            prompt_preview_chars: 200,
            app_dir: Arc::new(AppDir::new(tmp_app.path().to_path_buf())),
        };
        std::mem::forget(tmp_app);
        AppService::new(executor, log_config, vec![])
    }

    // ── (b) maybe_log_transcript returns Some when write fails ──────────

    #[tokio::test]
    async fn maybe_log_transcript_returns_some_on_write_failure() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let log_dir = tmp.path().to_path_buf();
        // Block write by creating a directory at the session file path.
        std::fs::create_dir_all(log_dir.join("fail-session.json"))
            .expect("pre-create dir to block write");
        let svc = make_app_service_with_log_dir(log_dir).await;
        let metrics = make_metrics_with_transcript();
        let result = make_finished_result(metrics);
        let warning = svc.maybe_log_transcript(&result, "fail-session");
        assert!(warning.is_some(), "expected Some warning on write failure");
        let msg = warning.unwrap();
        assert!(
            msg.contains("transcript"),
            "warning should mention 'transcript', got: {msg}"
        );
    }

    #[tokio::test]
    async fn maybe_log_transcript_returns_none_on_non_finished() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;
        let result = FeedResult::Accepted { remaining: 1 };
        let warning = svc.maybe_log_transcript(&result, "any-session");
        assert!(warning.is_none(), "Accepted result should return None");
    }

    // ── (c) splice_transcript_warning inserts field into JSON ───────────

    #[test]
    fn splice_transcript_warning_injects_field_when_some() {
        let json = r#"{"status":"finished","result":{}}"#;
        let out = splice_transcript_warning(json, Some("write failed".to_string()));
        let v: serde_json::Value = serde_json::from_str(&out).expect("valid JSON");
        assert_eq!(
            v["transcript_warning"].as_str(),
            Some("write failed"),
            "transcript_warning field should be present"
        );
        // Original fields are preserved.
        assert_eq!(v["status"].as_str(), Some("finished"));
    }

    #[test]
    fn splice_transcript_warning_passthrough_when_none() {
        let json = r#"{"status":"finished"}"#;
        let out = splice_transcript_warning(json, None);
        let v: serde_json::Value = serde_json::from_str(&out).expect("valid JSON");
        assert!(
            v.get("transcript_warning").is_none(),
            "transcript_warning must be absent when warning is None"
        );
    }

    // ── ST6: pool registry routing tests ────────────────────────────────────

    use crate::pool::PoolSessionEntry;

    /// T1: continue_single falls through to in-MCP path when session is not in pool registry.
    ///
    /// An unknown session ID should not be found in the pool registry and
    /// should reach the `SessionRegistry::feed_response` path, which returns
    /// an error because no session exists in the in-memory registry either.
    #[tokio::test]
    async fn continue_single_in_mcp_path_on_registry_miss() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;

        // The pool registry on disk and in-memory is empty (no workers registered).
        // continue_single should fall through to the in-MCP path and return
        // "not found" because the in-memory session registry also has nothing.
        let result = svc
            .continue_single(
                "nonexistent-session-id",
                "some response".to_string(),
                None,
                None,
            )
            .await;
        assert!(
            result.is_err(),
            "unknown session must return Err on in-MCP path"
        );
        let msg = result.unwrap_err();
        assert!(
            msg.contains("not found") || msg.contains("Continue failed"),
            "error must indicate session not found, got: {msg}"
        );
    }

    /// T2: AppService::new initialises pool_registry as empty when pool dir absent.
    ///
    /// Verifies that startup GC with a missing registry.json (normal first-run)
    /// produces an empty PoolRegistry (not an error).
    #[tokio::test]
    async fn app_service_new_initialises_empty_pool_registry() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;

        let reg = svc.pool_registry.read().await;
        assert!(
            reg.sessions.is_empty(),
            "pool registry must be empty on first-run (no registry.json)"
        );
    }

    /// T2b: AppService correctly stores pool registry paths derived from app_dir.
    ///
    /// Verifies that pool_dir / pool_reg_path / pool_lock_path are
    /// non-empty paths derived from state_dir/pool/*.
    #[tokio::test]
    async fn app_service_pool_paths_correctly_derived() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;

        assert!(
            svc.pool_dir.ends_with("pool"),
            "pool_dir must end in 'pool', got: {}",
            svc.pool_dir.display()
        );
        assert!(
            svc.pool_reg_path.ends_with("pool/registry.json"),
            "pool_reg_path must end in 'pool/registry.json', got: {}",
            svc.pool_reg_path.display()
        );
        assert!(
            svc.pool_lock_path.ends_with("pool/registry.lock"),
            "pool_lock_path must end in 'pool/registry.lock', got: {}",
            svc.pool_lock_path.display()
        );
    }

    /// T3: continue_single propagates PoolError::RegistryCorrupted to MCP wire.
    ///
    /// When registry.json is corrupt and there is a cache miss, continue_single
    /// must return Err (not silently proceed with empty registry). This verifies
    /// the CLAUDE.md §Error 伝播規律 invariant — no unwrap_or_default() swallowing.
    #[tokio::test]
    async fn continue_single_propagates_corrupted_registry_error() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;

        // Write a corrupt registry.json to the pool directory.
        let pool_dir = svc.pool_dir.clone();
        std::fs::create_dir_all(&pool_dir).expect("create pool dir");
        std::fs::write(pool_dir.join("registry.json"), b"{ not valid json !!!")
            .expect("write corrupt registry");

        // The in-memory cache is empty (startup GC failed on the corrupt file,
        // so pool_registry is empty default).  The disk read in continue_single
        // will hit the corrupt file and must propagate the error.
        let result = svc
            .continue_single("any-session-id", "response".to_string(), None, None)
            .await;
        assert!(
            result.is_err(),
            "corrupted registry must cause Err, not silent empty fallback"
        );
        let msg = result.unwrap_err();
        assert!(
            msg.contains("corrupted") || msg.contains("parse") || msg.contains("Continue failed"),
            "error must mention registry problem, got: {msg}"
        );
    }

    // ── pool_cache_reload_warning splice tests ───────────────────────────────

    use super::super::eval_store::splice_response_string;

    /// T1 (happy path): splice_response_string inserts pool_cache_reload_warning
    /// into a valid JSON object response.
    ///
    /// Verifies the crux-card constraint: cache-reload failure must surface on
    /// the MCP wire as an additive field, not remain warn!-only.
    #[test]
    fn splice_response_string_injects_cache_reload_warning() {
        let json = r#"{"status":"finished","result":{"ok":true}}"#;
        let msg = "failed to reload pool registry: No such file or directory";
        let out = splice_response_string(json, "pool_cache_reload_warning", msg);
        let v: serde_json::Value = serde_json::from_str(&out).expect("valid JSON");
        assert_eq!(
            v["pool_cache_reload_warning"].as_str(),
            Some(msg),
            "pool_cache_reload_warning must be present in response"
        );
        // Original fields preserved (additive, not destructive).
        assert_eq!(v["status"].as_str(), Some("finished"));
    }

    /// T2 (edge case): splice_response_string is a no-op when input is not a
    /// JSON object (e.g. bare string or array).
    ///
    /// Guards against panics when strategy output is malformed.
    #[test]
    fn splice_response_string_passthrough_on_non_object_json() {
        let non_object = r#""just a string""#;
        let out = splice_response_string(non_object, "pool_cache_reload_warning", "err");
        // Must return original unchanged.
        assert_eq!(out, non_object);
    }

    /// T3 (error path / None branch): when cache_reload_warning is None, the
    /// pool_cache_reload_warning field must NOT appear in the response JSON.
    ///
    /// Verifies the None arm of the new match block in run.rs leaves the JSON
    /// untouched, consistent with the pool_save_error pattern.
    #[test]
    fn splice_response_string_not_called_when_none() {
        let json = r#"{"status":"finished"}"#;
        // Simulate the None branch: we simply do not call splice_response_string.
        let v: serde_json::Value = serde_json::from_str(json).expect("valid JSON");
        assert!(
            v.get("pool_cache_reload_warning").is_none(),
            "pool_cache_reload_warning must be absent when no cache-reload error occurred"
        );
    }

    /// T1b: in-memory pool registry lookup finds an entry and routes to pool path.
    ///
    /// Inserts a live entry (current process PID) into the in-memory registry
    /// and verifies that continue_single attempts the pool path (fails with
    /// connection error because no real worker socket exists, not "not found").
    #[tokio::test]
    async fn continue_single_routes_to_pool_on_registry_hit() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let svc = make_app_service_with_log_dir(tmp.path().to_path_buf()).await;

        // Insert a fake entry pointing to a non-existent socket.
        // This simulates the case where a pool session was started.
        let fake_sock = tmp.path().join("nonexistent.sock");
        let entry = PoolSessionEntry::new(
            "test-pool-session",
            std::process::id(), // live PID — survives GC
            fake_sock.clone(),
            env!("CARGO_PKG_VERSION"),
        );
        {
            let mut reg = svc.pool_registry.write().await;
            reg.add(entry);
        }

        // continue_single should find the entry and attempt pool path.
        // The UDS connect will fail (no socket file) → PoolError::Connect → Err.
        // Importantly, the error is a connection error, NOT a "session not found" error.
        let result = svc
            .continue_single("test-pool-session", "response".to_string(), None, None)
            .await;
        assert!(
            result.is_err(),
            "pool path must fail with connect error (no real worker)"
        );
        let msg = result.unwrap_err();
        // The error must come from pool path (UDS connect), not from SessionRegistry.
        // "not found" would indicate the in-MCP path was taken instead.
        assert!(
            !msg.contains("session not found") || msg.contains("Continue failed"),
            "error must be from pool path (UDS connect), got: {msg}"
        );
    }

    // ── resolve_env unit tests ──────────────────────────────────────────────────

    use super::resolve_env;

    /// T1 (happy path): inject keys are accessible in the resolved map.
    ///
    /// Verifies the SPACE boundary inject path: keys supplied via
    /// `ctx.env.inject` appear in the frozen snapshot.
    #[test]
    fn resolve_env_inject_keys_readable() {
        let ctx = serde_json::json!({
            "env": {
                "inject": { "FOO": "bar", "BAZ": "qux" }
            }
        });
        let map = resolve_env(&ctx, None, None).expect("resolve_env should succeed");
        assert_eq!(map.get("FOO").map(String::as_str), Some("bar"));
        assert_eq!(map.get("BAZ").map(String::as_str), Some("qux"));
    }

    /// T1b (happy path): empty ctx produces an empty env map.
    ///
    /// Verifies that `alc.env` is always present (empty map is valid) even
    /// when no env configuration is supplied in the invocation context.
    #[test]
    fn resolve_env_empty_ctx_produces_empty_map() {
        let ctx = serde_json::Value::Null;
        let map = resolve_env(&ctx, None, None).expect("resolve_env with null ctx should succeed");
        assert!(map.is_empty(), "empty ctx must produce an empty env map");
    }

    /// T1c (happy path): inject priority over dotenv file for same key.
    ///
    /// Verifies the SOURCE boundary: inject (Layer 3) overwrites dotenv (Layer 2).
    #[test]
    fn resolve_env_inject_overwrites_dotenv() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let env_file = tmp.path().join(".env");
        // The .env file declares PRIORITY=from_dotenv.
        std::fs::write(&env_file, b"PRIORITY=from_dotenv\n").expect("write .env");

        let ctx = serde_json::json!({
            "env": {
                "dotenv": env_file.to_str().expect("valid path"),
                "inject": { "PRIORITY": "from_inject" }
            }
        });
        let map = resolve_env(&ctx, None, None).expect("resolve_env should succeed");
        // inject (higher priority) must win over dotenv.
        assert_eq!(
            map.get("PRIORITY").map(String::as_str),
            Some("from_inject"),
            "inject must shadow dotenv for the same key"
        );
    }

    /// T1d (happy path): dotenv file keys are loaded when path is absolute.
    ///
    /// Verifies Layer 2 (dotenv) of the SOURCE boundary merge chain.
    #[test]
    fn resolve_env_dotenv_absolute_path_loaded() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let env_file = tmp.path().join(".env");
        std::fs::write(&env_file, b"DOTENV_KEY=dotenv_val\n").expect("write .env");

        let ctx = serde_json::json!({
            "env": {
                "dotenv": env_file.to_str().expect("valid path")
            }
        });
        let map = resolve_env(&ctx, None, None).expect("resolve_env should succeed");
        assert_eq!(
            map.get("DOTENV_KEY").map(String::as_str),
            Some("dotenv_val"),
            "key from dotenv file must be accessible"
        );
    }

    /// T1e (happy path): allowlist filter retains only listed keys.
    ///
    /// Verifies alc.toml [env].allow filtering is applied after 3-source merge.
    #[test]
    fn resolve_env_allowlist_filters_inject_keys() {
        let ctx = serde_json::json!({
            "env": {
                "inject": { "ALLOWED": "yes", "BLOCKED": "no" }
            }
        });
        let allow = vec!["ALLOWED".to_string()];
        let map =
            resolve_env(&ctx, None, Some(allow.as_slice())).expect("resolve_env should succeed");
        assert_eq!(map.get("ALLOWED").map(String::as_str), Some("yes"));
        assert!(
            map.get("BLOCKED").is_none(),
            "BLOCKED key must be excluded by allowlist"
        );
    }

    /// T2 (boundary): allow_os=false (default) must not include any OS env vars.
    ///
    /// Verifies the SOURCE boundary: OS env is excluded unless explicitly opted in.
    #[test]
    fn resolve_env_allow_os_false_excludes_os_vars() {
        // PATH is nearly always set in the test environment.
        let ctx = serde_json::json!({ "env": { "allow_os": false } });
        let map = resolve_env(&ctx, None, None).expect("resolve_env should succeed");
        // Even if PATH is set in the OS, it must not appear in the snapshot.
        assert!(
            map.get("PATH").is_none(),
            "OS env must not leak when allow_os is false"
        );
    }

    /// T2b (boundary): relative dotenv path without project_root returns Err.
    ///
    /// Verifies the plan Risks #3 decision: relative path + None project_root = Err.
    #[test]
    fn resolve_env_relative_dotenv_without_project_root_errors() {
        let ctx = serde_json::json!({
            "env": { "dotenv": ".env" }
        });
        let result = resolve_env(&ctx, None, None);
        assert!(
            result.is_err(),
            "relative dotenv path without project_root must return Err"
        );
        let msg = result.unwrap_err();
        assert!(
            msg.contains("project_root"),
            "error must mention project_root, got: {msg}"
        );
    }

    /// T2c (boundary): relative dotenv path with project_root is resolved correctly.
    ///
    /// Verifies that a relative path is joined against project_root.
    #[test]
    fn resolve_env_relative_dotenv_with_project_root_resolved() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        std::fs::write(tmp.path().join(".env"), b"REL_KEY=rel_val\n").expect("write .env");

        let ctx = serde_json::json!({ "env": { "dotenv": ".env" } });
        let map = resolve_env(&ctx, Some(tmp.path()), None).expect("resolve_env should succeed");
        assert_eq!(
            map.get("REL_KEY").map(String::as_str),
            Some("rel_val"),
            "relative dotenv path must be resolved against project_root"
        );
    }

    /// T2d (boundary): empty allowlist (None) means no filtering — all keys pass through.
    #[test]
    fn resolve_env_none_allowlist_keeps_all_inject_keys() {
        let ctx = serde_json::json!({
            "env": { "inject": { "A": "1", "B": "2" } }
        });
        let map = resolve_env(&ctx, None, None).expect("resolve_env should succeed");
        assert_eq!(
            map.len(),
            2,
            "all inject keys must be retained when allowlist is None"
        );
    }

    /// T3 (error path): inject value that is not a string returns Err.
    ///
    /// Verifies that non-string inject values propagate as Result::Err (no silent drop).
    #[test]
    fn resolve_env_inject_non_string_value_errors() {
        let ctx = serde_json::json!({
            "env": { "inject": { "BAD": 42 } }
        });
        let result = resolve_env(&ctx, None, None);
        assert!(result.is_err(), "non-string inject value must return Err");
        let msg = result.unwrap_err();
        assert!(
            msg.contains("BAD"),
            "error must mention the offending key, got: {msg}"
        );
    }

    /// T3b (error path): inject object that is not an object returns Err.
    #[test]
    fn resolve_env_inject_not_an_object_errors() {
        let ctx = serde_json::json!({
            "env": { "inject": ["not", "an", "object"] }
        });
        let result = resolve_env(&ctx, None, None);
        assert!(result.is_err(), "non-object inject value must return Err");
    }

    /// T3c (error path): missing dotenv file propagates as Err (no silent skip).
    ///
    /// Verifies SOURCE boundary: dotenv I/O errors are surfaced, not swallowed.
    #[test]
    fn resolve_env_missing_dotenv_file_errors() {
        let ctx = serde_json::json!({
            "env": { "dotenv": "/nonexistent/path/to/.env" }
        });
        let result = resolve_env(&ctx, None, None);
        assert!(
            result.is_err(),
            "missing dotenv file must return Err, not empty map"
        );
        let msg = result.unwrap_err();
        assert!(
            msg.contains("dotenv"),
            "error must mention dotenv, got: {msg}"
        );
    }

    // ── resolve_pkg_type_lua unit tests (ST2) ───────────────────────────────

    use algocline_core::pkg::{PkgType, TypeSource};

    /// Build a temporary package directory with the given `init.lua` content
    /// and return the parent directory (the one to pass as a lib_path to
    /// `Executor::new`).
    fn make_temp_pkg(parent: &std::path::Path, pkg_name: &str, init_lua: &str) -> PathBuf {
        let pkg_dir = parent.join(pkg_name);
        std::fs::create_dir_all(&pkg_dir).expect("create pkg dir");
        std::fs::write(pkg_dir.join("init.lua"), init_lua).expect("write init.lua");
        parent.to_path_buf()
    }

    /// Build a minimal `AppService` whose executor can `require` packages from
    /// `pkg_root` (the parent directory that contains `<pkg_name>/init.lua`).
    async fn make_svc_with_pkg_root(pkg_root: PathBuf) -> AppService {
        let executor = Arc::new(
            algocline_engine::Executor::new(vec![pkg_root])
                .await
                .expect("executor"),
        );
        // `AppConfig::default()` (test-only) creates a fresh leaked tempdir and
        // sets log_enabled = false — suitable for unit tests.
        let log_config = super::super::config::AppConfig::default();
        AppService::new(executor, log_config, vec![])
    }

    /// T1 (boundary): `M.run` defined + no `meta.type` → `Some((Runnable, AutoDetectedRunnable))`.
    ///
    /// When `meta.type` is absent and `pkg.run` is a function, the snippet
    /// sets `meta.type = "runnable"` and `meta.type_source = "auto_detected_runnable"`.
    #[tokio::test]
    async fn resolve_pkg_type_lua_returns_auto_runnable() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let pkg_root = make_temp_pkg(
            tmp.path(),
            "auto_runnable",
            r#"local M = {}
M.meta = { name = "auto_runnable" }
M.run = function(ctx) return "ok" end
return M
"#,
        );
        let svc = make_svc_with_pkg_root(pkg_root).await;
        let result = svc
            .resolve_pkg_type_lua("auto_runnable")
            .await
            .expect("eval must succeed");
        assert_eq!(
            result,
            Some((PkgType::Runnable, TypeSource::AutoDetectedRunnable)),
            "M.run present + no meta.type must produce (Runnable, AutoDetectedRunnable)"
        );
    }

    /// T3 (error path): no `M.run` + no `meta.type` → `Some((Library, AutoDetectedLibrary))`.
    ///
    /// When `meta.type` is absent and `pkg.run` is not a function, the snippet
    /// sets `meta.type = "library"` and `meta.type_source = "auto_detected_library"`.
    /// This is the warn-eligible case — the crux constraint requires this specific
    /// `TypeSource` variant so `alc_pkg_doctor` / `alc_pkg_list` can fire the
    /// unmarked-library warning only for `AutoDetectedLibrary`, not for `None`.
    #[tokio::test]
    async fn resolve_pkg_type_lua_returns_auto_library() {
        let tmp = tempfile::tempdir().expect("test tempdir");
        let pkg_root = make_temp_pkg(
            tmp.path(),
            "auto_library",
            r#"local M = {}
M.meta = { name = "auto_library" }
-- no M.run defined
return M
"#,
        );
        let svc = make_svc_with_pkg_root(pkg_root).await;
        let result = svc
            .resolve_pkg_type_lua("auto_library")
            .await
            .expect("eval must succeed");
        assert_eq!(
            result,
            Some((PkgType::Library, TypeSource::AutoDetectedLibrary)),
            "no M.run + no meta.type must produce (Library, AutoDetectedLibrary)"
        );
    }
}
