"""
Authentication Router
Handles user registration and login
"""
from datetime import timedelta
from fastapi import APIRouter, Depends, HTTPException, status
from fastapi.security import OAuth2PasswordRequestForm
from sqlalchemy.orm import Session

from app.database import get_db
from app.models import User
from app.schemas import UserCreate, UserResponse, Token
from app.services.auth_service import (
    get_password_hash,
    authenticate_user,
    create_access_token,
    get_current_user
)
from app.config import ACCESS_TOKEN_EXPIRE_MINUTES

router = APIRouter()


@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
    
    - **username**: Unique username (3-50 characters)
    - **email**: Valid email address
    - **password**: Password (minimum 6 characters)
    """
    # Check if username 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 registered"
        )
    
    # Check if email 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"
        )
    
    # Create new user
    new_user = User(
        username=user_data.username,
        email=user_data.email,
        hashed_password=get_password_hash(user_data.password)
    )
    
    db.add(new_user)
    db.commit()
    db.refresh(new_user)
    
    return new_user


@router.post("/login", response_model=Token)
async def login(
    form_data: OAuth2PasswordRequestForm = Depends(),
    db: Session = Depends(get_db)
):
    """
    Login to get access token
    
    - **username**: Your username
    - **password**: Your password
    
    Returns JWT access token for authentication
    """
    user = authenticate_user(db, form_data.username, form_data.password)
    if not user:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    access_token_expires = timedelta(minutes=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 authenticated user information
    """
    return current_user