from datetime import timedelta
from typing import Any

from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session

from app.api.deps import get_current_active_user
from app.core.config import settings
from app.core.security import create_access_token
from app.crud import user as crud_user
from app.db.session import get_db
from app.models.user import User
from app.schemas.token import Token
from app.schemas.user import User as UserSchema
from app.schemas.user import UserCreate, UserUpdate

router = APIRouter()

@router.post(
    "/register",
    response_model=UserSchema,
    status_code=status.HTTP_201_CREATED
)
def create_user(
    *,
    db: Session = Depends(get_db),
    user_in: UserCreate,
) -> Any:
    """
    Create a new user.
    """
    # Check if user with given email exists
    user = crud_user.get_by_email(db, email=user_in.email)
    if user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )

    # Check if user with given username exists
    user = crud_user.get_by_username(db, username=user_in.username)
    if user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already taken"
        )

    # Create new user
    user = crud_user.create(db, obj_in=user_in)
    return user

@router.post("/login", response_model=Token)
def login_access_token(
    db: Session = Depends(get_db),
    form_data: OAuth2PasswordRequestForm = Depends()
) -> Any:
    """
    OAuth2 compatible token login, get an access token for future requests.
    """
    user = crud_user.authenticate(
        db=db, username=form_data.username, password=form_data.password
    )
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    if not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Inactive user"
        )

    access_token_expires = timedelta(minutes=settings.ACCESS_TOKEN_EXPIRE_MINUTES)
    return {
        "access_token": create_access_token(
            user.id, expires_delta=access_token_expires
        ),
        "token_type": "bearer",
    }

@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.put("/me", response_model=UserSchema)
def update_user_me(
    *,
    db: Session = Depends(get_db),
    user_in: UserUpdate,
    current_user: User = Depends(get_current_active_user),
) -> Any:
    """
    Update current user.
    """
    # Check if user is trying to update email and if email already exists
    if user_in.email and user_in.email != current_user.email:
        user = crud_user.get_by_email(db, email=user_in.email)
        if user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Email already registered"
            )

    # Check if user is trying to update username and if username already exists
    if user_in.username and user_in.username != current_user.username:
        user = crud_user.get_by_username(db, username=user_in.username)
        if user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Username already taken"
            )

    # Update user
    user = crud_user.update(db, db_obj=current_user, obj_in=user_in)
    return user