from fastapi import APIRouter, Depends, HTTPException, status, Form
from fastapi.security import OAuth2PasswordBearer, OAuth2PasswordRequestForm
from sqlalchemy.orm import Session
from datetime import timedelta
from jose import JWTError, jwt

from .. import schemas
from ..database import get_db
from ..config import settings
from ..services.auth_service import (
    authenticate_user, 
    create_access_token, 
    create_user,
    get_user_by_email
)

# OAuth2 scheme for token authentication
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="api/v1/token")

router = APIRouter()

async def get_current_user(token: str = Depends(oauth2_scheme), db: Session = Depends(get_db)):
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    try:
        payload = jwt.decode(token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm])
        email: str = payload.get("sub")
        if email is None:
            raise credentials_exception
        token_data = schemas.TokenData(email=email)
    except JWTError:
        raise credentials_exception
    
    user = get_user_by_email(db, email=token_data.email)
    if user is None:
        raise credentials_exception
    return user

@router.post("/token", response_model=schemas.Token)
async def login_for_access_token(form_data: OAuth2PasswordRequestForm = Depends(), db: Session = Depends(get_db)):
    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.jwt_expiration_minutes)
    access_token = create_access_token(
        data={"sub": user.email}, expires_delta=access_token_expires
    )
    return {"access_token": access_token, "token_type": "bearer"}

@router.post("/register", response_model=schemas.User)
def register_user(
    email: str = Form(...),
    name: str = Form(...),
    password: str = Form(...),
    phone: str = Form(...),
    db: Session = Depends(get_db)
):
    return create_user(db, name, email, password, phone)

@router.get("/users/me", response_model=schemas.User)
async def read_users_me(current_user = Depends(get_current_user)):
    return current_user