from typing import Any, List

from fastapi import APIRouter, Body, Depends, HTTPException
from fastapi.encoders import jsonable_encoder
from pydantic import EmailStr
from sqlalchemy.orm import Session

from app.core.deps import get_current_active_superuser, get_current_active_user, get_db
from app.models.user import User
from app.schemas.user import User as UserSchema
from app.schemas.user import UserCreate, UserUpdate
from app.services import user as user_service

router = APIRouter()


@router.get("/", response_model=List[UserSchema])
def read_users(
    db: Session = Depends(get_db),
    skip: int = 0,
    limit: int = 100,
    current_user: User = Depends(get_current_active_superuser),
) -> Any:
    """
    Retrieve users.
    """
    users = db.query(User).offset(skip).limit(limit).all()
    return users


@router.post("/", response_model=UserSchema)
def create_user(
    *,
    db: Session = Depends(get_db),
    user_in: UserCreate,
    current_user: User = Depends(get_current_active_superuser),
) -> Any:
    """
    Create new user.
    """
    # Check if username already exists
    user = user_service.get_by_username(db, username=user_in.username)
    if user:
        raise HTTPException(
            status_code=400,
            detail="A user with this username already exists",
        )
    
    # Also check email for uniqueness
    user = user_service.get_by_email(db, email=user_in.email)
    if user:
        raise HTTPException(
            status_code=400,
            detail="A user with this email already exists",
        )
        
    user = user_service.create(db, obj_in=user_in)
    return user


@router.put("/me", response_model=UserSchema)
def update_user_me(
    *,
    db: Session = Depends(get_db),
    password: str = Body(None),
    full_name: str = Body(None),
    username: str = Body(None),
    email: EmailStr = Body(None),
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Update own user.
    """
    current_user_data = jsonable_encoder(current_user)
    user_in = UserUpdate(**current_user_data)
    
    if password is not None:
        user_in.password = password
    if full_name is not None:
        user_in.full_name = full_name
    
    # Check for username uniqueness if username is being updated
    if username is not None and username != current_user.username:
        existing_user = user_service.get_by_username(db, username=username)
        if existing_user:
            raise HTTPException(
                status_code=400,
                detail="A user with this username already exists",
            )
        user_in.username = username
        
    # Check for email uniqueness if email is being updated
    if email is not None and email != current_user.email:
        existing_user = user_service.get_by_email(db, email=email)
        if existing_user:
            raise HTTPException(
                status_code=400,
                detail="A user with this email already exists",
            )
        user_in.email = email
        
    user = user_service.update(db, db_obj=current_user, obj_in=user_in)
    return user


@router.get("/me", response_model=UserSchema)
def read_user_me(
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Get current user.
    """
    return current_user


@router.get("/{user_id}", response_model=UserSchema)
def read_user_by_id(
    user_id: str,
    current_user: User = Depends(get_current_active_user),
    db: Session = Depends(get_db),
) -> Any:
    """
    Get a specific user by id.
    """
    user = user_service.get_by_id(db, user_id=user_id)
    if user == current_user:
        return user
    if not user_service.is_superuser(current_user):
        raise HTTPException(
            status_code=400, detail="The user doesn't have enough privileges"
        )
    return user


@router.put("/{user_id}", response_model=UserSchema)
def update_user(
    *,
    db: Session = Depends(get_db),
    user_id: str,
    user_in: UserUpdate,
    current_user: User = Depends(get_current_active_superuser),
) -> Any:
    """
    Update a user.
    """
    user = user_service.get_by_id(db, user_id=user_id)
    if not user:
        raise HTTPException(
            status_code=404,
            detail="The user with this id does not exist in the system",
        )
    user = user_service.update(db, db_obj=user, obj_in=user_in)
    return user