"""Authentication endpoints."""
from datetime import timedelta
from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from sqlalchemy.orm import Session

from app.core.database import get_db
from app.core.security import verify_password, create_access_token, decode_access_token
from app.core.config import settings
from app.models.user import User
from app.schemas.auth import Token
from app.schemas.user import UserCreate, UserResponse

router = APIRouter()
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="/api/v1/auth/login")

def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)) -> User:
    """Get the current authenticated user."""
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    payload = decode_access_token(token)
    if payload is None:
        raise credentials_exception
    
    username: str = payload.get("sub")
    if username is None:
        raise credentials_exception
    
    user = db.query(User).filter(User.username == username).first()
    if user is None:
        raise credentials_exception
    
    return user

@router.post("/register", response_model=UserResponse, status_code=status.HTTP_201_CREATED)
async def register(user_data: UserCreate, db: Session = Depends(get_db)):
    """Register a new user."""
    # Check if username 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"
        )
    
    # Check if email already exists
    if db.query(User).filter(User.email == user_data.email).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Email already registered"
        )
    
    # Create new user
    from app.core.security import get_password_hash
    db_user = User(
        username=user_data.username,
        email=user_data.email,
        full_name=user_data.full_name,
        hashed_password=get_password_hash(user_data.password),
        is_active=True,
        is_admin=False
    )
    
    db.add(db_user)
    db.commit()
    db.refresh(db_user)
    
    return db_user

@router.post("/login", response_model=Token)
async def login(form_data: OAuth2PasswordRequestForm = Depends(), db: Session = Depends(get_db)):
    """Login and get access token."""
    user = db.query(User).filter(User.username == form_data.username).first()
    
    if not user or not verify_password(form_data.password, user.hashed_password):
        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)
    access_token = create_access_token(
        data={"sub": user.username},
        expires_delta=access_token_expires
    )
    
    return {"access_token": access_token, "token_type": "bearer"}

@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