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

from database import get_db
from config import get_settings
from auth import (
    UserCreate, UserUpdate, UserResponse, Token,
    authenticate_user, create_user, create_access_token,
    get_user_by_email, get_current_active_user, get_password_hash
)
from models import User

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


@router.post("/signup", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
def signup(user_data: UserCreate, db: Session = Depends(get_db)):
    """Register a new user"""
    # Check if user exists
    existing_user = get_user_by_email(db, user_data.email)
    if existing_user:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )

    # Create user
    user = create_user(db, user_data)
    return user


@router.post("/login", response_model=Token)
def login(
    form_data: OAuth2PasswordRequestForm = Depends(),
    db: Session = Depends(get_db)
):
    """Login and get access token"""
    user = authenticate_user(db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect email or password",
            headers={"WWW-Authenticate": "Bearer"},
        )

    access_token_expires = timedelta(minutes=settings.access_token_expire_minutes)
    access_token = create_access_token(
        data={"sub": user.email}, expires_delta=access_token_expires
    )
    return {"access_token": access_token, "token_type": "bearer"}


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


@router.put("/me", response_model=UserResponse)
def update_current_user(
    user_update: UserUpdate,
    current_user: User = Depends(get_current_active_user),
    db: Session = Depends(get_db)
):
    """Update current user information"""
    update_data = user_update.model_dump(exclude_unset=True)

    for field, value in update_data.items():
        setattr(current_user, field, value)

    db.commit()
    db.refresh(current_user)
    return current_user


@router.post("/change-password")
def change_password(
    current_password: str,
    new_password: str,
    current_user: User = Depends(get_current_active_user),
    db: Session = Depends(get_db)
):
    """Change user password"""
    from auth import verify_password

    if not verify_password(current_password, current_user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Incorrect current password"
        )

    current_user.hashed_password = get_password_hash(new_password)
    db.commit()
    return {"message": "Password updated successfully"}


@router.delete("/me")
def delete_account(
    current_user: User = Depends(get_current_active_user),
    db: Session = Depends(get_db)
):
    """Delete user account"""
    db.delete(current_user)
    db.commit()
    return {"message": "Account deleted successfully"}