use crate::agents::AgentPool;
use crate::io::watcher::WatcherEvent;
use crate::state::SessionState;
use crate::store::JsonFileStore;
use crate::workflow::WorkflowState;
use poem::http::StatusCode;
use std::sync::Arc;
use tokio::sync::{broadcast, mpsc, oneshot};

/// 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<bool>,
}

#[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>,
    /// 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>>>,
}

#[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(".story_kit_store.json");
        let (watcher_tx, _) = broadcast::channel(64);
        let (perm_tx, perm_rx) = mpsc::unbounded_channel();
        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,
            perm_tx,
            perm_rx: Arc::new(tokio::sync::Mutex::new(perm_rx)),
        }
    }
}

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

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

#[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);
    }
}