//! Hand execution and run tracking
//!
//! # Approval Architecture
//!
//! Hands with `needs_approval: true` go through a two-phase flow:
//! 1. **Entry point** (Tauri command `hand_execute`): checks `needs_approval` flag and
//!    `autonomy_level`. If approval is required, creates a `PendingApproval` and returns
//!    immediately — the hand is NOT executed yet.
//! 2. **Approval** (Tauri command `hand_approve`): user approves → `respond_to_approval()`
//!    spawns `hands.execute()` directly (bypassing this `execute_hand()` method).
//!
//! This method (`execute_hand`) is the **direct execution path** used when approval is
//! NOT required, or when the user has opted into autonomous mode. For defense-in-depth,
//! we log a warning if a `needs_approval` hand reaches this path — it means the approval
//! gate was bypassed (e.g., by the scheduler or trigger manager, which intentionally bypass
//! approval for automated triggers).

use std::sync::Arc;
use zclaw_types::{Result, HandRun, HandRunId, HandRunStatus, HandRunFilter, TriggerSource};
use zclaw_hands::{HandContext, HandResult};

use super::Kernel;

impl Kernel {
    /// Get the hands registry
    pub fn hands(&self) -> &Arc<zclaw_hands::HandRegistry> {
        &self.hands
    }

    /// List all registered hands
    pub async fn list_hands(&self) -> Vec<zclaw_hands::HandConfig> {
        self.hands.list().await
    }

    /// Execute a hand with the given input, tracking the run.
    ///
    /// **Note:** For hands with `needs_approval: true`, the Tauri command layer should
    /// route through the approval flow instead of calling this method directly. Automated
    /// triggers (scheduler, trigger manager) intentionally bypass approval.
    pub async fn execute_hand(
        &self,
        hand_id: &str,
        input: serde_json::Value,
    ) -> Result<(HandResult, HandRunId)> {
        // Defense-in-depth audit: log if a needs_approval hand reaches the direct path
        let configs = self.hands.list().await;
        if let Some(config) = configs.iter().find(|c| c.id == hand_id) {
            if config.needs_approval {
                tracing::warn!(
                    "[Kernel] Hand '{}' has needs_approval=true but reached direct execution path. \
                    Caller should route through approval flow instead.",
                    hand_id
                );
            }
        }
        let run_id = HandRunId::new();
        let now = chrono::Utc::now().to_rfc3339();

        // Create the initial HandRun record
        let mut run = HandRun {
            id: run_id,
            hand_name: hand_id.to_string(),
            trigger_source: TriggerSource::Manual,
            params: input.clone(),
            status: HandRunStatus::Pending,
            result: None,
            error: None,
            duration_ms: None,
            created_at: now.clone(),
            started_at: None,
            completed_at: None,
        };
        self.memory.save_hand_run(&run).await?;

        // Transition to Running
        run.status = HandRunStatus::Running;
        run.started_at = Some(chrono::Utc::now().to_rfc3339());
        self.memory.update_hand_run(&run).await?;

        // Register cancellation flag
        let cancel_flag = Arc::new(std::sync::atomic::AtomicBool::new(false));
        self.running_hand_runs.insert(run_id, cancel_flag.clone());

        // Execute the hand (with optional timeout from HandConfig)
        let context = HandContext::default();
        let start = std::time::Instant::now();

        // Determine timeout: prefer HandConfig.timeout_secs, fallback to context default (300s)
        let timeout_secs = self.hands.get_config(hand_id)
            .await
            .map(|c| if c.timeout_secs > 0 { c.timeout_secs } else { context.timeout_secs })
            .unwrap_or(context.timeout_secs);

        let hand_result = tokio::time::timeout(
            std::time::Duration::from_secs(timeout_secs),
            self.hands.execute(hand_id, &context, input),
        ).await;

        let duration = start.elapsed();

        // Handle timeout
        let hand_result = match hand_result {
            Ok(result) => result,
            Err(_) => {
                // Timeout elapsed
                cancel_flag.store(true, std::sync::atomic::Ordering::Relaxed);
                let mut run_update = run.clone();
                run_update.status = HandRunStatus::Failed;
                run_update.error = Some(format!("Hand execution timed out after {}s", timeout_secs));
                run_update.completed_at = Some(chrono::Utc::now().to_rfc3339());
                run_update.duration_ms = Some(duration.as_millis() as u64);
                self.memory.update_hand_run(&run_update).await?;
                self.running_hand_runs.remove(&run_id);
                return Err(zclaw_types::ZclawError::Timeout(format!("Hand '{}' timed out after {}s", hand_id, timeout_secs)));
            }
        };

        // Check if cancelled during execution
        if cancel_flag.load(std::sync::atomic::Ordering::Relaxed) {
            let mut run_update = run.clone();
            run_update.status = HandRunStatus::Cancelled;
            run_update.completed_at = Some(chrono::Utc::now().to_rfc3339());
            run_update.duration_ms = Some(duration.as_millis() as u64);
            self.memory.update_hand_run(&run_update).await?;
            self.running_hand_runs.remove(&run_id);
            return Err(zclaw_types::ZclawError::Internal("Hand execution cancelled".to_string()));
        }

        // Remove from running map
        self.running_hand_runs.remove(&run_id);

        // Update HandRun with result
        let completed_at = chrono::Utc::now().to_rfc3339();
        match &hand_result {
            Ok(res) => {
                run.status = HandRunStatus::Completed;
                run.result = Some(res.output.clone());
                run.error = res.error.clone();
            }
            Err(e) => {
                run.status = HandRunStatus::Failed;
                run.error = Some(e.to_string());
            }
        }
        run.duration_ms = Some(duration.as_millis() as u64);
        run.completed_at = Some(completed_at);
        self.memory.update_hand_run(&run).await?;

        hand_result.map(|res| (res, run_id))
    }

    /// Execute a hand with a specific trigger source (for scheduled/event triggers).
    ///
    /// Automated trigger sources (Scheduler, Event, System) bypass the approval gate
    /// by design — the user explicitly configured these automated triggers.
    /// Manual trigger sources should go through the approval flow at the Tauri command layer.
    pub async fn execute_hand_with_source(
        &self,
        hand_id: &str,
        input: serde_json::Value,
        trigger_source: TriggerSource,
    ) -> Result<(HandResult, HandRunId)> {
        // Audit: warn if a Manual trigger bypasses approval
        if trigger_source == TriggerSource::Manual {
            let configs = self.hands.list().await;
            if let Some(config) = configs.iter().find(|c| c.id == hand_id) {
                if config.needs_approval {
                    tracing::warn!(
                        "[Kernel] Hand '{}' (Manual trigger) has needs_approval=true but bypassed approval. \
                        This should go through the approval flow.",
                        hand_id
                    );
                }
            }
        }

        let run_id = HandRunId::new();
        let now = chrono::Utc::now().to_rfc3339();

        let mut run = HandRun {
            id: run_id,
            hand_name: hand_id.to_string(),
            trigger_source,
            params: input.clone(),
            status: HandRunStatus::Pending,
            result: None,
            error: None,
            duration_ms: None,
            created_at: now,
            started_at: None,
            completed_at: None,
        };
        self.memory.save_hand_run(&run).await?;

        run.status = HandRunStatus::Running;
        run.started_at = Some(chrono::Utc::now().to_rfc3339());
        self.memory.update_hand_run(&run).await?;

        let cancel_flag = Arc::new(std::sync::atomic::AtomicBool::new(false));
        self.running_hand_runs.insert(run_id, cancel_flag.clone());

        let context = HandContext::default();
        let start = std::time::Instant::now();

        // P2-02: Apply timeout to execute_hand_with_source (same as execute_hand)
        let timeout_secs = self.hands.get_config(hand_id)
            .await
            .map(|c| if c.timeout_secs > 0 { c.timeout_secs } else { context.timeout_secs })
            .unwrap_or(context.timeout_secs);

        let hand_result = tokio::time::timeout(
            std::time::Duration::from_secs(timeout_secs),
            self.hands.execute(hand_id, &context, input),
        ).await;
        let duration = start.elapsed();

        // Check if cancelled during execution
        if cancel_flag.load(std::sync::atomic::Ordering::Relaxed) {
            run.status = HandRunStatus::Cancelled;
            run.completed_at = Some(chrono::Utc::now().to_rfc3339());
            run.duration_ms = Some(duration.as_millis() as u64);
            self.memory.update_hand_run(&run).await?;
            self.running_hand_runs.remove(&run_id);
            return Err(zclaw_types::ZclawError::Internal("Hand execution cancelled".to_string()));
        }

        self.running_hand_runs.remove(&run_id);

        let completed_at = chrono::Utc::now().to_rfc3339();
        // Handle timeout result
        let hand_result = match hand_result {
            Ok(result) => result,
            Err(_) => {
                // Timeout elapsed
                cancel_flag.store(true, std::sync::atomic::Ordering::Relaxed);
                run.status = HandRunStatus::Failed;
                run.error = Some(format!("Hand execution timed out after {}s", timeout_secs));
                run.duration_ms = Some(duration.as_millis() as u64);
                run.completed_at = Some(completed_at);
                self.memory.update_hand_run(&run).await?;
                return Err(zclaw_types::ZclawError::Internal(
                    format!("Hand '{}' timed out after {}s", hand_id, timeout_secs)
                ));
            }
        };

        match &hand_result {
            Ok(res) => {
                run.status = HandRunStatus::Completed;
                run.result = Some(res.output.clone());
                run.error = res.error.clone();
            }
            Err(e) => {
                run.status = HandRunStatus::Failed;
                run.error = Some(e.to_string());
            }
        }
        run.duration_ms = Some(duration.as_millis() as u64);
        run.completed_at = Some(completed_at);
        self.memory.update_hand_run(&run).await?;

        hand_result.map(|res| (res, run_id))
    }

    // ============================================================
    // Hand Run Tracking
    // ============================================================

    /// Get a hand run by ID
    pub async fn get_hand_run(&self, id: &HandRunId) -> Result<Option<HandRun>> {
        self.memory.get_hand_run(id).await
    }

    /// List hand runs with filter
    pub async fn list_hand_runs(&self, filter: &HandRunFilter) -> Result<Vec<HandRun>> {
        self.memory.list_hand_runs(filter).await
    }

    /// Count hand runs matching filter
    pub async fn count_hand_runs(&self, filter: &HandRunFilter) -> Result<u32> {
        self.memory.count_hand_runs(filter).await
    }

    /// Cancel a running hand execution
    pub async fn cancel_hand_run(&self, id: &HandRunId) -> Result<()> {
        if let Some((_, flag)) = self.running_hand_runs.remove(id) {
            flag.store(true, std::sync::atomic::Ordering::Relaxed);

            // Note: the actual status update happens in execute_hand_with_source
            // when it detects the cancel flag
            Ok(())
        } else {
            // Not currently running — check if exists at all
            let run = self.memory.get_hand_run(id).await?;
            match run {
                Some(r) if r.status == HandRunStatus::Pending => {
                    let mut updated = r;
                    updated.status = HandRunStatus::Cancelled;
                    updated.completed_at = Some(chrono::Utc::now().to_rfc3339());
                    self.memory.update_hand_run(&updated).await?;
                    Ok(())
                }
                Some(r) => Err(zclaw_types::ZclawError::InvalidInput(
                    format!("Cannot cancel hand run {} with status {}", id, r.status)
                )),
                None => Err(zclaw_types::ZclawError::NotFound(
                    format!("Hand run {} not found", id)
                )),
            }
        }
    }
}