//! Application context — shared state (`AppContext`) threaded through all HTTP handlers.
use crate::agents::{AgentPool, ReconciliationEvent};
use crate::chat::timer::TimerStore;
use crate::io::watcher::WatcherEvent;
use crate::rebuild::{BotShutdownNotifier, ShutdownReason};
use crate::state::SessionState;
use crate::store::JsonFileStore;
use crate::workflow::WorkflowState;
use poem::http::StatusCode;
use std::collections::HashMap;
use std::path::PathBuf;
use std::sync::Arc;
use tokio::sync::{broadcast, mpsc, oneshot};

/// A running or completed test job spawned by the `run_tests` MCP tool.
pub struct TestJob {
    /// The child process handle. `None` once the process has exited and results
    /// have been collected.
    pub child: Option<std::process::Child>,
    /// Populated once the child exits.
    pub result: Option<TestJobResult>,
    /// When the job was started.
    pub started_at: std::time::Instant,
}

/// The result of a completed test job.
#[derive(Clone)]
pub struct TestJobResult {
    pub passed: bool,
    pub exit_code: i32,
    pub tests_passed: u64,
    pub tests_failed: u64,
    pub output: String,
}

/// Shared registry of in-flight and recently completed test jobs, keyed by
/// worktree path.
pub type TestJobRegistry = Arc<std::sync::Mutex<HashMap<PathBuf, TestJob>>>;

/// The user's decision when responding to a permission dialog.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PermissionDecision {
    /// One-time denial.
    Deny,
    /// One-time approval.
    Approve,
    /// Approve and persist the rule to `.claude/settings.json` so Claude Code's
    /// built-in permission system handles future checks without prompting.
    AlwaysAllow,
}

/// A permission request forwarded from the MCP `prompt_permission` tool to the
/// active WebSocket session. The MCP handler blocks on `response_tx` until the
/// user approves or denies via the frontend dialog.
pub struct PermissionForward {
    pub request_id: String,
    pub tool_name: String,
    pub tool_input: serde_json::Value,
    pub response_tx: oneshot::Sender<PermissionDecision>,
}

#[derive(Clone)]
pub struct AppContext {
    pub state: Arc<SessionState>,
    pub store: Arc<JsonFileStore>,
    pub workflow: Arc<std::sync::Mutex<WorkflowState>>,
    pub agents: Arc<AgentPool>,
    /// Broadcast channel for filesystem watcher events. WebSocket handlers
    /// subscribe to this to push lifecycle notifications to connected clients.
    pub watcher_tx: broadcast::Sender<WatcherEvent>,
    /// Broadcast channel for startup reconciliation progress events.
    /// WebSocket handlers subscribe to this to push real-time reconciliation
    /// updates to connected clients.
    pub reconciliation_tx: broadcast::Sender<ReconciliationEvent>,
    /// Sender for permission requests originating from the MCP
    /// `prompt_permission` tool. The MCP handler sends a [`PermissionForward`]
    /// and awaits the oneshot response.
    pub perm_tx: mpsc::UnboundedSender<PermissionForward>,
    /// Receiver for permission requests. The active WebSocket handler locks
    /// this and polls for incoming permission forwards.
    pub perm_rx: Arc<tokio::sync::Mutex<mpsc::UnboundedReceiver<PermissionForward>>>,
    /// Child process of the QA app launched for manual testing.
    /// Only one instance runs at a time.
    pub qa_app_process: Arc<std::sync::Mutex<Option<std::process::Child>>>,
    /// Best-effort shutdown notifier for active bot channels (Slack / WhatsApp).
    ///
    /// When set, the MCP `rebuild_and_restart` tool uses this to announce the
    /// shutdown to configured channels before re-execing the server binary.
    /// `None` when no webhook-based bot transport is configured.
    pub bot_shutdown: Option<Arc<BotShutdownNotifier>>,
    /// Watch sender used to signal the Matrix bot task that the server is
    /// shutting down (rebuild path).  The bot task listens for this signal and
    /// sends a shutdown announcement to all configured rooms.
    ///
    /// Wrapped in `Arc` so `AppContext` can implement `Clone`.
    /// `None` when no Matrix bot is configured.
    pub matrix_shutdown_tx: Option<Arc<tokio::sync::watch::Sender<Option<ShutdownReason>>>>,
    /// Shared rate-limit retry timer store.
    ///
    /// Used by MCP tools (`move_story`, `stop_agent`) to cancel pending timers
    /// when the user manually intervenes (bug 501).  Shared with the tick loop
    /// spawned by the bot so that cancellations take effect in-memory rather
    /// than only on disk.
    pub timer_store: Arc<TimerStore>,
    /// Registry of running/completed test jobs spawned by the `run_tests` MCP
    /// tool. Keyed by worktree path so each worktree has at most one active job.
    pub test_jobs: TestJobRegistry,
}

#[cfg(test)]
impl AppContext {
    pub fn new_test(project_root: std::path::PathBuf) -> Self {
        let state = SessionState::default();
        *state.project_root.lock().unwrap() = Some(project_root.clone());
        let store_path = project_root.join(".huskies_store.json");
        let (watcher_tx, _) = broadcast::channel(64);
        let (reconciliation_tx, _) = broadcast::channel(64);
        let (perm_tx, perm_rx) = mpsc::unbounded_channel();
        let timer_store = Arc::new(TimerStore::load(
            project_root.join(".huskies").join("timers.json"),
        ));
        Self {
            state: Arc::new(state),
            store: Arc::new(JsonFileStore::new(store_path).unwrap()),
            workflow: Arc::new(std::sync::Mutex::new(WorkflowState::default())),
            agents: Arc::new(AgentPool::new(3001, watcher_tx.clone())),
            watcher_tx,
            reconciliation_tx,
            perm_tx,
            perm_rx: Arc::new(tokio::sync::Mutex::new(perm_rx)),
            qa_app_process: Arc::new(std::sync::Mutex::new(None)),
            bot_shutdown: None,
            matrix_shutdown_tx: None,
            timer_store,
            test_jobs: Arc::new(std::sync::Mutex::new(HashMap::new())),
        }
    }
}

pub type OpenApiResult<T> = poem::Result<T>;

pub fn bad_request(message: String) -> poem::Error {
    poem::Error::from_string(message, StatusCode::BAD_REQUEST)
}

pub fn not_found(message: String) -> poem::Error {
    poem::Error::from_string(message, StatusCode::NOT_FOUND)
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn bad_request_returns_400_status() {
        let err = bad_request("something went wrong".to_string());
        assert_eq!(err.status(), StatusCode::BAD_REQUEST);
    }

    #[test]
    fn bad_request_accepts_empty_message() {
        let err = bad_request(String::new());
        assert_eq!(err.status(), StatusCode::BAD_REQUEST);
    }

    #[test]
    fn permission_decision_equality() {
        assert_eq!(PermissionDecision::Deny, PermissionDecision::Deny);
        assert_eq!(PermissionDecision::Approve, PermissionDecision::Approve);
        assert_eq!(
            PermissionDecision::AlwaysAllow,
            PermissionDecision::AlwaysAllow
        );
        assert_ne!(PermissionDecision::Deny, PermissionDecision::Approve);
        assert_ne!(PermissionDecision::Approve, PermissionDecision::AlwaysAllow);
    }

    #[test]
    fn not_found_returns_404_status() {
        let err = not_found("item not found".to_string());
        assert_eq!(err.status(), StatusCode::NOT_FOUND);
    }
}