import os
from datetime import timedelta
from dotenv import load_dotenv
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker, Session
from fastapi import FastAPI, HTTPException, Depends
from werkzeug.security import generate_password_hash, check_password_hash

from models.Base import Base
from models.User import User
from models.Message import Message
from models.Conversation import Conversation
from utils.validators import UserCreate, UserLogin, Token
from utils.auth import create_access_token

ACCESS_TOKEN_EXPIRE_MINUTES = 30  # Token expiration time


load_dotenv()

app = FastAPI()
engine = create_engine(os.environ["DB_URL"])
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base.metadata.create_all(bind=engine)


# Dependency to get the SQLAlchemy session
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


@app.post("/register", response_model=dict)
def register(user: UserCreate, db: Session = Depends(get_db)):
    existing_user = db.query(User).filter(User.email == user.email).first()

    if existing_user:
        raise HTTPException(
            status_code=400,
            detail="The provided email is already taken.",
        )

    hashed_password = generate_password_hash(user.password)
    new_user = User(
        email=user.email,
        password_hash=hashed_password,
    )

    db.add(new_user)
    db.commit()
    db.refresh(new_user)

    return {"message": "User registered successfully."}


@app.post("/login", response_model=Token)
def login(user: UserLogin, db: Session = Depends(get_db)):
    # Check if the user exists
    db_user = db.query(User).filter(User.email == user.email).first()
    if not db_user or not check_password_hash(db_user.password_hash, user.password):
        raise HTTPException(status_code=401, detail="Invalid email or password")

    # Create a token
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={
            "email": db_user.email,
            "userId": db_user.id,
        },
        expires_delta=access_token_expires,
    )

    return {"access_token": access_token, "token_type": "bearer"}


@app.get("/chats")
def chats():
    pass


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(app)