from fastapi import APIRouter, Depends, HTTPException, status, Query
from sqlalchemy.orm import Session
from typing import List, Optional
from uuid import UUID

from app.core import get_db, get_current_user, get_current_admin_user, get_password_hash
from app.models import User, UserRole
from app.schemas import UserCreate, UserUpdate, UserResponse

router = APIRouter(prefix="/users", tags=["User Management"])


@router.get("/me", response_model=UserResponse)
async def get_current_user_info(current_user: User = Depends(get_current_user)):
    """Get current user information"""
    return current_user


@router.get("", response_model=List[UserResponse])
async def list_users(
    skip: int = Query(0, ge=0),
    limit: int = Query(50, ge=1, le=100),
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_admin_user)
):
    """List all users (admin only)"""
    users = db.query(User).offset(skip).limit(limit).all()
    return users


@router.post("", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
async def create_user(
    user_data: UserCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_admin_user)
):
    """Create a new user (admin only)"""
    # Check if username or email already exists
    if db.query(User).filter(User.username == user_data.username).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already registered"
        )
    
    if db.query(User).filter(User.email == user_data.email).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )
    
    user = User(
        email=user_data.email,
        username=user_data.username,
        hashed_password=get_password_hash(user_data.password),
        full_name=user_data.full_name,
        phone=user_data.phone,
        role=user_data.role
    )
    db.add(user)
    db.commit()
    db.refresh(user)
    
    return user


@router.get("/{user_id}", response_model=UserResponse)
async def get_user(
    user_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_admin_user)
):
    """Get user by ID (admin only)"""
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="User not found"
        )
    return user


@router.put("/{user_id}", response_model=UserResponse)
async def update_user(
    user_id: UUID,
    user_data: UserUpdate,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_admin_user)
):
    """Update user (admin only)"""
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="User not found"
        )
    
    update_data = user_data.model_dump(exclude_unset=True)
    for field, value in update_data.items():
        setattr(user, field, value)
    
    db.commit()
    db.refresh(user)
    return user


@router.delete("/{user_id}", status_code=status.HTTP_204_NO_CONTENT)
async def delete_user(
    user_id: UUID,
    db: Session = Depends(get_db),
    current_user: User = Depends(get_current_admin_user)
):
    """Delete user (admin only)"""
    if str(user_id) == str(current_user.id):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Cannot delete yourself"
        )
    
    user = db.query(User).filter(User.id == user_id).first()
    if not user:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="User not found"
        )
    
    db.delete(user)
    db.commit()
    return None