from datetime import timedelta
from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session
from app.core.database import get_db
from app.core.auth import (
    verify_password,
    get_password_hash,
    create_access_token,
    get_current_user
)
from app.core.config import settings
from app.models.models import User
from app.schemas.schemas import (
    UserCreate,
    UserLogin,
    UserResponse,
    UserUpdate,
    Token
)

router = APIRouter(prefix="/auth", tags=["Authentication"])


@router.post("/register", response_model=UserResponse)
def register(user_data: UserCreate, db: Session = Depends(get_db)):
    # Check if email already exists
    db_user = db.query(User).filter(User.email == user_data.email).first()
    if db_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )

    # Check if username already exists
    db_user = db.query(User).filter(User.username == user_data.username).first()
    if db_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Username already taken"
        )

    # Create new user
    hashed_password = get_password_hash(user_data.password)
    new_user = User(
        email=user_data.email,
        username=user_data.username,
        hashed_password=hashed_password,
        role="user",
        is_active=True
    )
    db.add(new_user)
    db.commit()
    db.refresh(new_user)

    return new_user


@router.post("/login", response_model=Token)
def login(login_data: UserLogin, db: Session = Depends(get_db)):
    # Find user by email
    user = db.query(User).filter(User.email == login_data.email).first()

    if not user or not verify_password(login_data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email 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)
    access_token = create_access_token(
        data={"sub": str(user.id), "email": user.email, "role": user.role},
        expires_delta=access_token_expires
    )

    return {"access_token": access_token, "token_type": "bearer"}


@router.get("/me", response_model=UserResponse)
def get_me(current_user: User = Depends(get_current_user)):
    return current_user


@router.put("/me", response_model=UserResponse)
def update_me(
    user_data: UserUpdate,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    if user_data.email:
        existing_user = db.query(User).filter(
            User.email == user_data.email,
            User.id != current_user.id
        ).first()
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Email already registered"
            )
        current_user.email = user_data.email

    if user_data.username:
        existing_user = db.query(User).filter(
            User.username == user_data.username,
            User.id != current_user.id
        ).first()
        if existing_user:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Username already taken"
            )
        current_user.username = user_data.username

    if user_data.password:
        current_user.hashed_password = get_password_hash(user_data.password)

    db.commit()
    db.refresh(current_user)

    return current_user