from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from typing import List
from uuid import UUID
from app.core.database import get_db
from app.core.security import get_current_user
from app.models.user import User, UserRole
from app.models.queue import Queue, QueueAgent
from app.models.quick_reply import QuickReply
from app.schemas.queue import (
    QueueCreate, QueueUpdate, QueueResponse, QueueDetailResponse,
    QueueAgentAdd, QueueAgentResponse,
    QuickReplyCreate, QuickReplyUpdate, QuickReplyResponse
)

router = APIRouter(prefix="/api/queues", tags=["queues"])


def require_admin(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role != UserRole.ADMIN:
        raise HTTPException(status_code=403, detail="Admin required")
    return current_user


def require_supervisor(current_user: User = Depends(get_current_user)) -> User:
    if current_user.role not in [UserRole.ADMIN, UserRole.SUPERVISOR]:
        raise HTTPException(status_code=403, detail="Supervisor or Admin required")
    return current_user


@router.post("", response_model=QueueResponse)
def create_queue(
    request: QueueCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_admin),
) -> Queue:
    queue = Queue(**request.model_dump())
    db.add(queue)
    db.commit()
    db.refresh(queue)
    return queue


@router.get("", response_model=List[QueueResponse])
def list_queues(
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
) -> List[QueueResponse]:
    queues = db.query(Queue).filter(Queue.is_active == True).all()
    result = []
    for q in queues:
        q_dict = QueueResponse.model_validate(q).model_dump()
        q_dict["agent_count"] = len(q.agents)
        result.append(QueueResponse(**q_dict))
    return result


@router.get("/{queue_id}", response_model=QueueDetailResponse)
def get_queue(
    queue_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
) -> QueueDetailResponse:
    queue = db.query(Queue).filter(Queue.id == queue_id).first()
    if not queue:
        raise HTTPException(status_code=404, detail="Queue not found")

    agents_data = []
    for qa in queue.agents:
        agents_data.append(QueueAgentResponse(
            id=qa.id,
            user_id=qa.user_id,
            user_name=qa.user.name if qa.user else None,
            user_email=qa.user.email if qa.user else None,
            is_supervisor=qa.is_supervisor,
            skills=qa.skills or [],
            created_at=qa.created_at,
        ))

    return QueueDetailResponse(
        **QueueResponse.model_validate(queue).model_dump(),
        agents=agents_data,
        agent_count=len(agents_data),
    )


@router.put("/{queue_id}", response_model=QueueResponse)
def update_queue(
    queue_id: UUID,
    request: QueueUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_admin),
) -> Queue:
    queue = db.query(Queue).filter(Queue.id == queue_id).first()
    if not queue:
        raise HTTPException(status_code=404, detail="Queue not found")

    for key, value in request.model_dump(exclude_unset=True).items():
        setattr(queue, key, value)

    db.commit()
    db.refresh(queue)
    return queue


@router.delete("/{queue_id}")
def delete_queue(
    queue_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_admin),
) -> dict:
    queue = db.query(Queue).filter(Queue.id == queue_id).first()
    if not queue:
        raise HTTPException(status_code=404, detail="Queue not found")

    queue.is_active = False
    db.commit()
    return {"success": True}


@router.post("/{queue_id}/agents", response_model=QueueAgentResponse)
def add_agent_to_queue(
    queue_id: UUID,
    request: QueueAgentAdd,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_admin),
) -> QueueAgentResponse:
    queue = db.query(Queue).filter(Queue.id == queue_id).first()
    if not queue:
        raise HTTPException(status_code=404, detail="Queue not found")

    existing = db.query(QueueAgent).filter(
        QueueAgent.queue_id == queue_id,
        QueueAgent.user_id == request.user_id
    ).first()
    if existing:
        raise HTTPException(status_code=400, detail="Agent already in queue")

    qa = QueueAgent(
        queue_id=queue_id,
        user_id=request.user_id,
        is_supervisor=request.is_supervisor,
        skills=request.skills,
    )
    db.add(qa)
    db.commit()
    db.refresh(qa)

    return QueueAgentResponse(
        id=qa.id,
        user_id=qa.user_id,
        user_name=qa.user.name if qa.user else None,
        user_email=qa.user.email if qa.user else None,
        is_supervisor=qa.is_supervisor,
        skills=qa.skills or [],
        created_at=qa.created_at,
    )


@router.delete("/{queue_id}/agents/{user_id}")
def remove_agent_from_queue(
    queue_id: UUID,
    user_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_admin),
) -> dict:
    qa = db.query(QueueAgent).filter(
        QueueAgent.queue_id == queue_id,
        QueueAgent.user_id == user_id
    ).first()
    if not qa:
        raise HTTPException(status_code=404, detail="Agent not in queue")

    db.delete(qa)
    db.commit()
    return {"success": True}


@router.get("/quick-replies", response_model=List[QuickReplyResponse])
def list_quick_replies(
    queue_id: UUID = None,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_user),
) -> List[QuickReply]:
    query = db.query(QuickReply)
    if queue_id:
        query = query.filter(
            (QuickReply.queue_id == queue_id) | (QuickReply.queue_id == None)
        )
    else:
        query = query.filter(QuickReply.queue_id == None)

    return query.all()


@router.post("/quick-replies", response_model=QuickReplyResponse)
def create_quick_reply(
    request: QuickReplyCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> QuickReply:
    qr = QuickReply(
        **request.model_dump(),
        created_by=current_user.id,
    )
    db.add(qr)
    db.commit()
    db.refresh(qr)
    return qr


@router.put("/quick-replies/{reply_id}", response_model=QuickReplyResponse)
def update_quick_reply(
    reply_id: UUID,
    request: QuickReplyUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> QuickReply:
    qr = db.query(QuickReply).filter(QuickReply.id == reply_id).first()
    if not qr:
        raise HTTPException(status_code=404, detail="Quick reply not found")

    for key, value in request.model_dump(exclude_unset=True).items():
        setattr(qr, key, value)

    db.commit()
    db.refresh(qr)
    return qr


@router.delete("/quick-replies/{reply_id}")
def delete_quick_reply(
    reply_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> dict:
    qr = db.query(QuickReply).filter(QuickReply.id == reply_id).first()
    if not qr:
        raise HTTPException(status_code=404, detail="Quick reply not found")

    db.delete(qr)
    db.commit()
    return {"success": True}