from uuid import UUID
from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select, func
from sqlalchemy.orm import selectinload
from ..database import get_db
from ..models.user import User
from ..models.room import Room, RoomParticipant
from ..models.track import RoomQueue
from ..schemas.room import RoomCreate, RoomResponse, RoomDetailResponse, QueueAdd, QueueAddMultiple, QueueItemResponse
from ..schemas.track import TrackResponse
from ..schemas.user import UserResponse
from ..services.auth import get_current_user
from ..services.sync import manager
from ..config import get_settings

settings = get_settings()
router = APIRouter(prefix="/api/rooms", tags=["rooms"])


@router.get("", response_model=list[RoomResponse])
async def get_rooms(db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(Room, func.count(RoomParticipant.user_id).label("participants_count"))
        .outerjoin(RoomParticipant)
        .group_by(Room.id)
        .order_by(Room.created_at.desc())
    )
    rooms = []
    for room, count in result.all():
        room_dict = {
            "id": room.id,
            "name": room.name,
            "owner_id": room.owner_id,
            "current_track_id": room.current_track_id,
            "playback_position": room.playback_position,
            "is_playing": room.is_playing,
            "created_at": room.created_at,
            "participants_count": count,
        }
        rooms.append(RoomResponse(**room_dict))
    return rooms


@router.post("", response_model=RoomResponse)
async def create_room(
    room_data: RoomCreate,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    room = Room(name=room_data.name, owner_id=current_user.id)
    db.add(room)
    await db.flush()
    return RoomResponse(
        id=room.id,
        name=room.name,
        owner_id=room.owner_id,
        current_track_id=room.current_track_id,
        playback_position=room.playback_position,
        is_playing=room.is_playing,
        created_at=room.created_at,
        participants_count=0,
    )


@router.get("/{room_id}", response_model=RoomDetailResponse)
async def get_room(room_id: UUID, db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(Room)
        .options(
            selectinload(Room.owner),
            selectinload(Room.current_track),
            selectinload(Room.participants).selectinload(RoomParticipant.user),
        )
        .where(Room.id == room_id)
    )
    room = result.scalar_one_or_none()

    if not room:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")

    return RoomDetailResponse(
        id=room.id,
        name=room.name,
        owner=UserResponse.model_validate(room.owner),
        current_track=TrackResponse.model_validate(room.current_track) if room.current_track else None,
        playback_position=room.playback_position,
        is_playing=room.is_playing,
        created_at=room.created_at,
        participants=[UserResponse.model_validate(p.user) for p in room.participants],
    )


@router.delete("/{room_id}")
async def delete_room(
    room_id: UUID,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(select(Room).where(Room.id == room_id))
    room = result.scalar_one_or_none()

    if not room:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")

    if room.owner_id != current_user.id:
        raise HTTPException(status_code=status.HTTP_403_FORBIDDEN, detail="Not room owner")

    # Уведомляем всех подключенных пользователей о удалении комнаты
    await manager.broadcast_to_room(
        room_id,
        {"type": "room_deleted", "message": "Room has been deleted by owner"},
    )

    # Отключаем всех пользователей от WebSocket
    if room_id in manager.active_connections:
        connections = list(manager.active_connections[room_id])
        for websocket, user_id in connections:
            try:
                await websocket.close(code=1000, reason="Room deleted")
            except Exception:
                pass
            manager.disconnect(websocket, room_id, user_id)

    # Удаляем комнату (cascade delete удалит participants, queue, messages)
    await db.delete(room)

    return {"status": "deleted"}


@router.post("/{room_id}/join")
async def join_room(
    room_id: UUID,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(select(Room).where(Room.id == room_id))
    room = result.scalar_one_or_none()

    if not room:
        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Room not found")

    # Check participant limit
    result = await db.execute(
        select(func.count(RoomParticipant.user_id)).where(RoomParticipant.room_id == room_id)
    )
    count = result.scalar()
    if count >= settings.max_room_participants:
        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Room is full")

    # Check if already joined
    result = await db.execute(
        select(RoomParticipant).where(
            RoomParticipant.room_id == room_id,
            RoomParticipant.user_id == current_user.id,
        )
    )
    if result.scalar_one_or_none():
        return {"status": "already joined"}

    participant = RoomParticipant(room_id=room_id, user_id=current_user.id)
    db.add(participant)

    # Notify others
    await manager.broadcast_to_room(
        room_id,
        {"type": "user_joined", "user": {"id": str(current_user.id), "username": current_user.username}},
    )

    return {"status": "joined"}


@router.post("/{room_id}/leave")
async def leave_room(
    room_id: UUID,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(
        select(RoomParticipant).where(
            RoomParticipant.room_id == room_id,
            RoomParticipant.user_id == current_user.id,
        )
    )
    participant = result.scalar_one_or_none()

    if participant:
        await db.delete(participant)

        # Notify others
        await manager.broadcast_to_room(
            room_id,
            {"type": "user_left", "user_id": str(current_user.id)},
        )

    return {"status": "left"}


@router.get("/{room_id}/queue", response_model=list[QueueItemResponse])
async def get_queue(room_id: UUID, db: AsyncSession = Depends(get_db)):
    result = await db.execute(
        select(RoomQueue)
        .options(selectinload(RoomQueue.track))
        .where(RoomQueue.room_id == room_id)
        .order_by(RoomQueue.position)
    )
    queue_items = result.scalars().all()
    return [
        QueueItemResponse(
            track=TrackResponse.model_validate(item.track),
            added_by=item.added_by
        )
        for item in queue_items
    ]


@router.post("/{room_id}/queue")
async def add_to_queue(
    room_id: UUID,
    data: QueueAdd,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    # Check if track already in queue
    result = await db.execute(
        select(RoomQueue).where(
            RoomQueue.room_id == room_id,
            RoomQueue.track_id == data.track_id,
        )
    )
    existing_item = result.scalar_one_or_none()

    if existing_item:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Track already in queue",
        )

    # Get max position
    result = await db.execute(
        select(func.max(RoomQueue.position)).where(RoomQueue.room_id == room_id)
    )
    max_pos = result.scalar() or 0

    queue_item = RoomQueue(
        room_id=room_id,
        track_id=data.track_id,
        position=max_pos + 1,
        added_by=current_user.id,
    )
    db.add(queue_item)
    await db.flush()

    # Notify others
    await manager.broadcast_to_room(
        room_id,
        {"type": "queue_updated"},
    )

    return {"status": "added"}


@router.post("/{room_id}/queue/bulk")
async def add_multiple_to_queue(
    room_id: UUID,
    data: QueueAddMultiple,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    """Add multiple tracks to queue at once, skipping duplicates."""
    if not data.track_ids:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="No tracks provided",
        )

    # Get existing tracks in queue
    result = await db.execute(
        select(RoomQueue.track_id).where(RoomQueue.room_id == room_id)
    )
    existing_track_ids = set(result.scalars().all())

    # Filter out duplicates
    new_track_ids = [tid for tid in data.track_ids if tid not in existing_track_ids]

    if not new_track_ids:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="All tracks already in queue",
        )

    # Get max position
    result = await db.execute(
        select(func.max(RoomQueue.position)).where(RoomQueue.room_id == room_id)
    )
    max_pos = result.scalar() or 0

    # Add all new tracks
    added_count = 0
    for i, track_id in enumerate(new_track_ids):
        queue_item = RoomQueue(
            room_id=room_id,
            track_id=track_id,
            position=max_pos + i + 1,
            added_by=current_user.id,
        )
        db.add(queue_item)
        added_count += 1

    await db.flush()

    # Notify others
    await manager.broadcast_to_room(
        room_id,
        {"type": "queue_updated"},
    )

    skipped_count = len(data.track_ids) - added_count
    return {
        "status": "added",
        "added": added_count,
        "skipped": skipped_count,
    }


@router.delete("/{room_id}/queue/{track_id}")
async def remove_from_queue(
    room_id: UUID,
    track_id: UUID,
    db: AsyncSession = Depends(get_db),
    current_user: User = Depends(get_current_user),
):
    result = await db.execute(
        select(RoomQueue).where(
            RoomQueue.room_id == room_id,
            RoomQueue.track_id == track_id,
        )
    )
    queue_item = result.scalar_one_or_none()

    if not queue_item:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Track not in queue"
        )

    # Check if user added this track to queue
    if queue_item.added_by != current_user.id:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Can only remove tracks you added"
        )

    await db.delete(queue_item)

    # Notify others
    await manager.broadcast_to_room(
        room_id,
        {"type": "queue_updated"},
    )

    return {"status": "removed"}