//! Hand commands: list, execute, approve, cancel, get, run_status, run_list, run_cancel
//!
//! Hands are autonomous capabilities registered in the Kernel's HandRegistry.
//! Hand execution can require approval depending on autonomy level and config.

use serde::{Deserialize, Serialize};
use serde_json;
use tauri::{AppHandle, Emitter, State};

use super::KernelState;

// ============================================================================
// Hands Commands - Autonomous Capabilities
// ============================================================================

/// Hand information response for frontend
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct HandInfoResponse {
    pub id: String,
    pub name: String,
    pub description: String,
    pub status: String,
    pub requirements_met: bool,
    pub needs_approval: bool,
    pub dependencies: Vec<String>,
    pub tags: Vec<String>,
    pub enabled: bool,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub category: Option<String>,
    #[serde(skip_serializing_if = "Option::is_none")]
    pub icon: Option<String>,
    #[serde(default)]
    pub tool_count: u32,
    #[serde(default)]
    pub metric_count: u32,
}

impl From<zclaw_hands::HandConfig> for HandInfoResponse {
    fn from(config: zclaw_hands::HandConfig) -> Self {
        // Determine status based on enabled and dependencies
        let status = if !config.enabled {
            "unavailable".to_string()
        } else if config.needs_approval {
            "needs_approval".to_string()
        } else {
            "idle".to_string()
        };

        // Extract category from tags if present
        let category = config.tags.iter().find(|t| {
            ["research", "automation", "browser", "data", "media", "communication"].contains(&t.as_str())
        }).cloned();

        // Map tags to icon
        let icon = if config.tags.contains(&"browser".to_string()) {
            Some("globe".to_string())
        } else if config.tags.contains(&"research".to_string()) {
            Some("search".to_string())
        } else if config.tags.contains(&"media".to_string()) {
            Some("video".to_string())
        } else if config.tags.contains(&"data".to_string()) {
            Some("database".to_string())
        } else if config.tags.contains(&"communication".to_string()) {
            Some("message-circle".to_string())
        } else {
            Some("zap".to_string())
        };

        Self {
            id: config.id,
            name: config.name,
            description: config.description,
            status,
            requirements_met: config.enabled && config.dependencies.is_empty(),
            needs_approval: config.needs_approval,
            dependencies: config.dependencies,
            tags: config.tags,
            enabled: config.enabled,
            category,
            icon,
            tool_count: 0, // P2-03: TODO — populated from hand execution metadata
            metric_count: 0,
        }
    }
}

/// Hand execution result
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct HandResult {
    pub success: bool,
    pub output: serde_json::Value,
    pub error: Option<String>,
    pub duration_ms: Option<u64>,
    pub run_id: Option<String>,
}

impl From<zclaw_hands::HandResult> for HandResult {
    fn from(result: zclaw_hands::HandResult) -> Self {
        Self {
            success: result.success,
            output: result.output,
            error: result.error,
            duration_ms: result.duration_ms,
            run_id: None,
        }
    }
}

/// List all registered hands
///
/// Returns hands from the Kernel's HandRegistry.
/// Hands are registered during kernel initialization.
// @reserved: Hand autonomous capabilities
// @connected
#[tauri::command]
pub async fn hand_list(
    state: State<'_, KernelState>,
) -> Result<Vec<HandInfoResponse>, String> {
    let kernel_lock = state.lock().await;

    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized. Call kernel_init first.".to_string())?;

    let hands = kernel.list_hands().await;
    let registry = kernel.hands();

    // P2-03: Populate tool_count/metric_count from actual Hand instances
    let mut results = Vec::new();
    for config in hands {
        let (tool_count, metric_count) = registry.get_counts(&config.id).await;
        let mut info = HandInfoResponse::from(config);
        info.tool_count = tool_count;
        info.metric_count = metric_count;
        results.push(info);
    }
    Ok(results)
}

/// Execute a hand
///
/// Executes a hand with the given ID and input.
/// If the hand has `needs_approval = true`, creates a pending approval instead.
/// Returns the hand result as JSON, or a pending status with approval ID.
// @reserved: Hand autonomous capabilities
// @connected
#[tauri::command]
pub async fn hand_execute(
    state: State<'_, KernelState>,
    id: String,
    input: serde_json::Value,
    autonomy_level: Option<String>,
) -> Result<HandResult, String> {
    let kernel_lock = state.lock().await;

    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized. Call kernel_init first.".to_string())?;

    // Autonomy guard: supervised mode requires approval for ALL hands
    if autonomy_level.as_deref() == Some("supervised") {
        let approval = kernel.create_approval(id.clone(), input).await;
        return Ok(HandResult {
            success: false,
            output: serde_json::json!({
                "status": "pending_approval",
                "approval_id": approval.id,
                "hand_id": approval.hand_id,
                "message": "监督模式下所有 Hand 执行需要用户审批"
            }),
            error: None,
            duration_ms: None,
            run_id: None,
        });
    }

    // Check if hand requires approval (assisted mode or no autonomy level specified).
    // In autonomous mode, the user has opted in to bypass per-hand approval gates.
    if autonomy_level.as_deref() != Some("autonomous") {
        let hands = kernel.list_hands().await;
        if let Some(hand_config) = hands.iter().find(|h| h.id == id) {
            if hand_config.needs_approval {
                let approval = kernel.create_approval(id.clone(), input).await;
                return Ok(HandResult {
                    success: false,
                    output: serde_json::json!({
                        "status": "pending_approval",
                        "approval_id": approval.id,
                        "hand_id": approval.hand_id,
                        "message": "This hand requires approval before execution"
                    }),
                    error: None,
                    duration_ms: None,
                    run_id: None,
                });
            }
        }
    }

    // Execute hand directly (returns result + run_id for tracking)
    let (result, run_id) = kernel.execute_hand(&id, input).await
        .map_err(|e| format!("Failed to execute hand: {}", e))?;

    let mut hand_result = HandResult::from(result);
    hand_result.run_id = Some(run_id.to_string());
    Ok(hand_result)
}

/// Approve a hand execution
///
/// When approved, the kernel's `respond_to_approval` internally spawns the Hand
/// execution.  We additionally emit Tauri events so the frontend can track when
/// the execution finishes.
// @reserved: Hand approval workflow
// @connected
#[tauri::command]
pub async fn hand_approve(
    app: AppHandle,
    state: State<'_, KernelState>,
    hand_name: String,
    run_id: String,
    approved: bool,
    reason: Option<String>,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    tracing::info!(
        "[hand_approve] hand={}, run_id={}, approved={}, reason={:?}",
        hand_name, run_id, approved, reason
    );

    // Verify the approval belongs to the specified hand before responding.
    // This prevents cross-hand approval attacks where a run_id from one hand
    // is used to approve a different hand's pending execution.
    let approvals = kernel.list_approvals().await;
    let entry = approvals.iter().find(|a| a.id == run_id && a.status == "pending")
        .ok_or_else(|| format!("Approval not found or already resolved: {}", run_id))?;

    if entry.hand_id != hand_name {
        return Err(format!(
            "Approval run_id {} belongs to hand '{}', not '{}' as requested",
            run_id, entry.hand_id, hand_name
        ));
    }

    kernel.respond_to_approval(&run_id, approved, reason).await
        .map_err(|e| format!("Failed to approve hand: {}", e))?;

    // When approved, monitor the Hand execution and emit events to the frontend
    if approved {
        let approval_id = run_id.clone();
        let hand_id = hand_name.clone();
        let kernel_state: KernelState = (*state).clone();

        tokio::spawn(async move {
            // Poll the approval status until it transitions from "approved" to
            // "completed" or "failed" (set by the kernel's spawned task).
            // Timeout after 5 minutes to avoid hanging forever.
            let timeout = tokio::time::Duration::from_secs(300);
            let poll_interval = tokio::time::Duration::from_millis(500);

            let result = tokio::time::timeout(timeout, async {
                loop {
                    tokio::time::sleep(poll_interval).await;

                    let kernel_lock = kernel_state.lock().await;
                    if let Some(kernel) = kernel_lock.as_ref() {
                        // Use get_approval to check any status (not just "pending")
                        if let Some(entry) = kernel.get_approval(&approval_id).await {
                            match entry.status.as_str() {
                                "completed" => {
                                    tracing::info!("[hand_approve] Hand '{}' execution completed for approval {}", hand_id, approval_id);
                                    return (true, None::<String>);
                                }
                                "failed" => {
                                    let error_msg = entry.input.get("error")
                                        .and_then(|v| v.as_str())
                                        .unwrap_or("Unknown error")
                                        .to_string();
                                    tracing::warn!("[hand_approve] Hand '{}' execution failed for approval {}: {}", hand_id, approval_id, error_msg);
                                    return (false, Some(error_msg));
                                }
                                _ => {} // still running (status is "approved")
                            }
                        } else {
                            // Entry disappeared entirely — kernel was likely restarted
                            return (false, Some("Approval entry disappeared".to_string()));
                        }
                    } else {
                        return (false, Some("Kernel not available".to_string()));
                    }
                }
            }).await;

            let (success, error) = match result {
                Ok((s, e)) => (s, e),
                Err(_) => (false, Some("Hand execution timed out (5 minutes)".to_string())),
            };

            let _ = app.emit("hand-execution-complete", serde_json::json!({
                "approvalId": approval_id,
                "handId": hand_id,
                "success": success,
                "error": error,
            }));
        });
    }

    Ok(serde_json::json!({
        "status": if approved { "approved" } else { "rejected" },
        "hand_name": hand_name,
    }))
}

/// Cancel a hand execution
// @connected
#[tauri::command]
pub async fn hand_cancel(
    state: State<'_, KernelState>,
    hand_name: String,
    run_id: String,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    tracing::info!(
        "[hand_cancel] hand={}, run_id={}",
        hand_name, run_id
    );

    // Verify the approval belongs to the specified hand before cancelling
    let approvals = kernel.list_approvals().await;
    let entry = approvals.iter().find(|a| a.id == run_id && a.status == "pending")
        .ok_or_else(|| format!("Approval not found or already resolved: {}", run_id))?;

    if entry.hand_id != hand_name {
        return Err(format!(
            "Approval run_id {} belongs to hand '{}', not '{}' as requested",
            run_id, entry.hand_id, hand_name
        ));
    }

    kernel.cancel_approval(&run_id).await
        .map_err(|e| format!("Failed to cancel hand: {}", e))?;

    Ok(serde_json::json!({ "status": "cancelled", "hand_name": hand_name }))
}

// ============================================================
// Hand Stub Commands (not yet fully implemented)
// ============================================================

/// Get detailed info for a single hand
// @connected
#[tauri::command]
pub async fn hand_get(
    state: State<'_, KernelState>,
    name: String,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    let hands = kernel.list_hands().await;
    let found = hands.iter().find(|h| h.id == name)
        .ok_or_else(|| format!("Hand '{}' not found", name))?;

    Ok(serde_json::to_value(found)
        .map_err(|e| format!("Serialization error: {}", e))?)
}

/// Get status of a specific hand run
// @connected
#[tauri::command]
pub async fn hand_run_status(
    state: State<'_, KernelState>,
    run_id: String,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    let parsed_id: zclaw_types::HandRunId = run_id.parse()
        .map_err(|e| format!("Invalid run ID: {}", e))?;

    let run = kernel.get_hand_run(&parsed_id).await
        .map_err(|e| format!("Failed to get hand run: {}", e))?;

    match run {
        Some(r) => Ok(serde_json::to_value(r)
            .map_err(|e| format!("Serialization error: {}", e))?),
        None => Ok(serde_json::json!({
            "status": "not_found",
            "run_id": run_id,
            "message": "Hand run not found"
        })),
    }
}

/// List run history for a hand (or all hands)
// @connected
#[tauri::command]
pub async fn hand_run_list(
    state: State<'_, KernelState>,
    hand_name: Option<String>,
    status: Option<String>,
    limit: Option<u32>,
    offset: Option<u32>,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    let filter = zclaw_types::HandRunFilter {
        hand_name,
        status: status.map(|s| s.parse()).transpose()
            .map_err(|e| format!("Invalid status filter: {}", e))?,
        limit,
        offset,
    };

    let runs = kernel.list_hand_runs(&filter).await
        .map_err(|e| format!("Failed to list hand runs: {}", e))?;
    let total = kernel.count_hand_runs(&filter).await
        .map_err(|e| format!("Failed to count hand runs: {}", e))?;

    Ok(serde_json::json!({
        "runs": runs,
        "total": total,
        "limit": filter.limit.unwrap_or(20),
        "offset": filter.offset.unwrap_or(0),
    }))
}

/// @reserved — no frontend UI yet
/// Cancel a running hand execution
#[tauri::command]
pub async fn hand_run_cancel(
    state: State<'_, KernelState>,
    run_id: String,
) -> Result<serde_json::Value, String> {
    let kernel_lock = state.lock().await;
    let kernel = kernel_lock.as_ref()
        .ok_or_else(|| "Kernel not initialized".to_string())?;

    let parsed_id: zclaw_types::HandRunId = run_id.parse()
        .map_err(|e| format!("Invalid run ID: {}", e))?;

    kernel.cancel_hand_run(&parsed_id).await
        .map_err(|e| format!("Failed to cancel hand run: {}", e))?;

    Ok(serde_json::json!({
        "status": "cancelled",
        "run_id": run_id
    }))
}