from datetime import datetime, timedelta

from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy import func
from sqlalchemy.orm import Session

from app.core.database import get_db
from app.core.security import get_current_user
from app.models.queue import Queue
from app.models.user import User, UserRole, UserStatus
from app.models.whatsapp import Conversation, ConversationStatus, Message

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


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.get("/dashboard")
def get_dashboard(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> dict:
    """Get supervisor dashboard data"""
    now = datetime.utcnow()
    today_start = now.replace(hour=0, minute=0, second=0, microsecond=0)

    status_counts = {}
    for status in ConversationStatus:
        count = db.query(Conversation).filter(Conversation.status == status).count()
        status_counts[status.value] = count

    waiting_conversations = db.query(Conversation).filter(
        Conversation.status == ConversationStatus.WAITING
    ).count()

    active_agents = db.query(User).filter(
        User.status == UserStatus.ONLINE,
        User.is_active == True,
    ).count()

    total_agents = db.query(User).filter(
        User.role.in_([UserRole.AGENT, UserRole.SUPERVISOR]),
        User.is_active == True,
    ).count()

    resolved_today = db.query(Conversation).filter(
        Conversation.resolved_at >= today_start
    ).count()

    messages_today = db.query(Message).filter(
        Message.created_at >= today_start
    ).count()

    csat_result = db.query(func.avg(Conversation.csat_score)).filter(
        Conversation.csat_score != None,
        Conversation.resolved_at >= today_start,
    ).scalar()
    avg_csat = round(float(csat_result), 2) if csat_result else None

    return {
        "conversations": {
            "by_status": status_counts,
            "waiting": waiting_conversations,
            "resolved_today": resolved_today,
        },
        "agents": {
            "online": active_agents,
            "total": total_agents,
        },
        "messages_today": messages_today,
        "avg_csat": avg_csat,
    }


@router.get("/agents")
def get_agents_status(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> list[dict]:
    """Get detailed agent status for supervisor view"""
    agents = db.query(User).filter(
        User.role.in_([UserRole.AGENT, UserRole.SUPERVISOR]),
        User.is_active == True,
    ).all()

    today_start = datetime.utcnow().replace(hour=0, minute=0, second=0, microsecond=0)
    result = []

    for agent in agents:
        active = db.query(Conversation).filter(
            Conversation.assigned_to == agent.id,
            Conversation.status == ConversationStatus.ACTIVE,
        ).count()

        waiting = db.query(Conversation).filter(
            Conversation.assigned_to == agent.id,
            Conversation.status == ConversationStatus.WAITING,
        ).count()

        resolved_today = db.query(Conversation).filter(
            Conversation.assigned_to == agent.id,
            Conversation.resolved_at >= today_start,
        ).count()

        result.append({
            "id": str(agent.id),
            "name": agent.name,
            "email": agent.email,
            "role": agent.role.value,
            "status": agent.status.value,
            "active_conversations": active,
            "waiting_conversations": waiting,
            "resolved_today": resolved_today,
        })

    return result


@router.get("/queues")
def get_queues_status(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> list[dict]:
    """Get queue status for supervisor view"""
    queues = db.query(Queue).filter(Queue.is_active == True).all()

    result = []
    for queue in queues:
        waiting = db.query(Conversation).filter(
            Conversation.queue_id == queue.id,
            Conversation.status == ConversationStatus.WAITING,
        ).count()

        active = db.query(Conversation).filter(
            Conversation.queue_id == queue.id,
            Conversation.status == ConversationStatus.ACTIVE,
        ).count()

        online_agents = sum(
            1 for qa in queue.agents
            if qa.user and qa.user.status == UserStatus.ONLINE
        )

        result.append({
            "id": str(queue.id),
            "name": queue.name,
            "waiting_conversations": waiting,
            "active_conversations": active,
            "online_agents": online_agents,
            "total_agents": len(queue.agents),
            "sla_first_response": queue.sla_first_response,
        })

    return result


@router.get("/conversations/critical")
def get_critical_conversations(
    db: Session = Depends(get_db),
    current_user: User = Depends(require_supervisor),
) -> list[dict]:
    """Get conversations that need attention"""
    now = datetime.utcnow()

    long_wait = db.query(Conversation).filter(
        Conversation.status == ConversationStatus.WAITING,
        Conversation.last_message_at < now - timedelta(minutes=5),
    ).all()

    high_priority = db.query(Conversation).filter(
        Conversation.priority.in_(["high", "urgent"]),
        Conversation.status.in_([ConversationStatus.WAITING, ConversationStatus.ACTIVE]),
    ).all()

    long_wait_ids = {conv.id for conv in long_wait}
    result = []
    seen_ids = set()

    for conv in long_wait + high_priority:
        if conv.id in seen_ids:
            continue
        seen_ids.add(conv.id)

        reason = "long_wait" if conv.id in long_wait_ids else "high_priority"

        result.append({
            "id": str(conv.id),
            "contact_name": conv.contact.name if conv.contact else "Unknown",
            "contact_phone": conv.contact.phone_number if conv.contact else "",
            "status": conv.status.value,
            "priority": conv.priority,
            "assigned_to": str(conv.assigned_to) if conv.assigned_to else None,
            "last_message_at": conv.last_message_at.isoformat() if conv.last_message_at else None,
            "reason": reason,
        })

    return result