from datetime import timedelta

from fastapi.security import OAuth2PasswordRequestForm
from fastapi import APIRouter, Depends, HTTPException, status
import pymongo

import app.config as config
from app.models import User, Token, HTTPError
from app.dto import UserRegisterDTO
from app.serializers import user_serialize
from app.utils import get_current_user, create_access_token, get_password_hash, verify_password

# Database setup
client = pymongo.MongoClient(config.MONGODB_URL, username=config.MONGODB_USERNAME, password=config.MONGODB_PASSWORD)
db = client[config.MONGODB_DATABASE]

users_collection = db["users"]

auth_router = APIRouter(
    tags=["Auth"]
)

@auth_router.post(
    path="/register",
    response_model=Token,
    responses={409: {"model": HTTPError}}
)
async def register(user: UserRegisterDTO):
    user_exists = users_collection.find_one({"username": user.username})
    if user_exists:
        raise HTTPException(
            status_code=status.HTTP_409_CONFLICT,
            detail="Username already used"
        )

    hashed_password = get_password_hash(user.password)
    user_id = users_collection.insert_one({"username": user.username, "password": hashed_password})

    access_token_expires = timedelta(minutes=config.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", "user_id": str(user_id.inserted_id)}

@auth_router.post(
    path="/login", 
    response_model=Token,
    responses={401: {"model": HTTPError}}
)
async def login(form_data: OAuth2PasswordRequestForm = Depends()):
    user = users_collection.find_one({"username": form_data.username})
    if not user or not verify_password(form_data.password, user["password"]):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    access_token_expires = timedelta(minutes=config.ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(data={"sub": form_data.username}, expires_delta=access_token_expires)

    return {"access_token": access_token, "token_type": "bearer", "user_id": str(user["_id"])}


@auth_router.get(
    path="/logout",
    responses={401: {"model": HTTPError}}
)
async def logout(current_user: User = Depends(get_current_user)):
    return {"message": "Logged out"}