use std::pin::Pin;
use std::sync::Arc;

use chrono::Utc;
use db::cache::AppCache;
use db::database::AppDatabase;
use queue::MessageProducer;
use uuid::Uuid;

use super::ai_mode_streaming_post::finalize_mode_stream;
use super::ai_mode_streaming_steps::build_mode_chunk_callback;
use super::sequence::next_room_message_seq_internal;
use crate::connection::RoomConnectionManager;
use agent::chat::{AiRequest, ChatService};

#[allow(dead_code)]

pub type RunModeFn = Box<
    dyn FnOnce(
            Arc<ChatService>,
            AiRequest,
            Arc<
                dyn Fn(String, String, bool) -> Pin<Box<dyn Future<Output = ()> + Send>>
                    + Send
                    + Sync,
            >,
        ) -> Pin<
            Box<dyn Future<Output = Result<(String, i64, i64), agent::AgentError>> + Send>,
        > + Send,
>;

#[allow(dead_code)]
pub async fn run_mode_streaming(
    chat_service: Arc<ChatService>,
    request: AiRequest,
    room_id: Uuid,
    project_id: Uuid,
    model_id: Uuid,
    lock_guard: crate::room_ai_queue::RoomAiLockGuard,
    db: AppDatabase,
    cache: AppCache,
    queue: MessageProducer,
    room_manager: Arc<RoomConnectionManager>,
    mode_name_str: &str,
    run: RunModeFn,
) {
    let mode_name = mode_name_str.to_string();

    let streaming_msg_id = Uuid::now_v7();
    let seq = match next_room_message_seq_internal(room_id, &db, &cache).await {
        Ok(s) => s,
        Err(e) => {
            tracing::error!(error = %e, "Failed to get seq for {} streaming", mode_name);
            return;
        }
    };

    let ai_display_name = request.model.name.clone();
    let _ = room_manager
        .register_stream_channel(streaming_msg_id, room_id, Some(ai_display_name.clone()))
        .await;

    use queue::RoomMessageStreamChunkEvent;
    let initial_event = RoomMessageStreamChunkEvent {
        message_id: streaming_msg_id,
        room_id,
        seq: 0,
        content: String::new(),
        done: false,
        error: None,
        display_name: Some(ai_display_name.clone()),
        chunk_type: Some("thinking".to_string()),
    };
    room_manager.broadcast_stream_chunk(initial_event).await;

    let now = Utc::now();

    tokio::spawn(async move {
        let _lock_guard = lock_guard;
        let cancel = room_manager.register_stream_cancel(room_id).await;

        let ai_typing_id = Uuid::parse_str("00000000-0000-0000-0000-000000000001")
            .expect("constant UUID should always parse");

        let typing_start = queue::TypingEvent {
            room_id,
            user_id: ai_typing_id,
            username: ai_display_name.clone(),
            avatar_url: None,
            action: "start".to_string(),
            sender_type: Some("ai".to_string()),
        };
        room_manager
            .broadcast_typing(room_id, typing_start.clone())
            .await;

        let (typing_cancel_tx, typing_cancel_rx) = tokio::sync::oneshot::channel::<()>();
        let typing_renew_handle = tokio::spawn({
            let mut interval = tokio::time::interval(std::time::Duration::from_secs(30));
            interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);
            let mgr = room_manager.clone();
            let evt = typing_start.clone();
            async move {
                tokio::select! {
                    _ = typing_cancel_rx => {}
                    _ = async {
                        loop {
                            interval.tick().await;
                            mgr.broadcast_typing(room_id, evt.clone()).await;
                        }
                    } => {}
                }
            }
        });

        let state = build_mode_chunk_callback(
            streaming_msg_id,
            room_id,
            &ai_display_name,
            cancel,
            room_manager.clone(),
            queue.clone(),
        );

        let on_chunk = state.on_chunk.clone();
        let result = run(chat_service, request, on_chunk).await;

        finalize_mode_stream(
            result,
            state,
            streaming_msg_id,
            room_id,
            project_id,
            model_id,
            seq,
            now,
            &ai_display_name,
            &mode_name,
            &db,
            &queue,
            &room_manager,
        )
        .await;

        let _ = typing_cancel_tx.send(());
        typing_renew_handle.abort();
        let typing_stop = queue::TypingEvent {
            room_id,
            user_id: ai_typing_id,
            username: ai_display_name.clone(),
            avatar_url: None,
            action: "stop".to_string(),
            sender_type: Some("ai".to_string()),
        };
        room_manager.broadcast_typing(room_id, typing_stop).await;

        room_manager.unregister_stream_cancel(room_id).await;
        room_manager.close_stream_channel(streaming_msg_id).await;
    });
}