#auth.py

from fastapi import Depends, HTTPException, Form, status
from fastapi.security import OAuth2PasswordBearer
from pydantic import BaseModel
from sqlalchemy.orm import Session
from database import get_db, get_user_by_email  # Import database functions
from models import User, VerificationToken
import jwt
from passlib.context import CryptContext
from datetime import datetime, timedelta
import os

yoursecretkey = os.environ['my_secret_key']

class AuthViews:
    def __init__(self):
        self.pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
        self.SECRET_KEY = yoursecretkey  # Replace with your actual secret key
        self.ALGORITHM = "HS256"
        self.ACCESS_TOKEN_EXPIRE_MINUTES = 30
    def create_access_token(self, data: dict, expires_delta: timedelta):
        to_encode = data.copy()
        expire = datetime.utcnow() + expires_delta
        to_encode.update({"exp": expire})
        encoded_jwt = jwt.encode(to_encode, self.SECRET_KEY, algorithm=self.ALGORITHM)
        return encoded_jwt
         
auth_views = AuthViews()
oauth2_scheme = OAuth2PasswordBearer(tokenUrl="token")

def verify_token(token: str = Depends(oauth2_scheme)):
    try:
        payload = jwt.decode(token, auth_views.SECRET_KEY, algorithms=[auth_views.ALGORITHM])
        return payload.get("sub")
    except jwt.ExpiredSignatureError:
        raise HTTPException(status_code=401, detail="Token has expired")
    except jwt.PyJWTError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Could not validate credentials",
            headers={"WWW-Authenticate": "Bearer"},
        )

class UserCreate(BaseModel):
    username: str
    email: str
    password: str
    confirm_password: str


# Use auth_views.pwd_context to access the password context from the AuthViews instance
def authenticate_user(db: Session, email: str, password: str):
    user = get_user_by_email(db, email)
    if user is None:
        raise HTTPException(status_code=400, detail="User not found")

    # Use the pwd_context from the auth_views instance
    if not auth_views.pwd_context.verify(password, user.hashed_password):
        raise HTTPException(status_code=400, detail="Incorrect password")

    return user



from emailx import send_verification_email, generate_verification_token

def get_user_by_verification_token(db: Session, verification_token: str):
    return db.query(User).filter(User.email_verification_token == verification_token).first()

def verify_email(verification_token: str, db: Session = Depends(get_db)):
    # Verify the email using the token
    user = get_user_by_verification_token(db, verification_token)
    
    if not user:
        raise HTTPException(status_code=400, detail="Invalid verification token")

    if user.is_verified:
        raise HTTPException(status_code=400, detail="Email already verified")

    # Mark the email as verified
    user.is_verified = True
    user.email_verification_token = None  # Optionally clear the verification token
    db.commit()
    return {"message": "Email verification successful"}



def register(user: UserCreate, db: Session):
    # Validate email format and check for existing users
    db_user = get_user_by_email(db, user.email)
    if db_user:
        raise HTTPException(status_code=400, detail="Email already registered")

    # Hash the password
    hashed_password = auth_views.pwd_context.hash(user.password)

    # Generate a verification token
    verification_token = generate_verification_token(user.email)
    reset_link = f"https://gregniuki-loginauth.hf.space/verify?token={verification_token}"
    # Send a verification email
    send_verification_email(user.email, reset_link)

    # Verify the email
   # verify_email(verification_token, db)

    # Create the user in the database
    # Set the email_verification_token field in the User model
    user_in_db = User(
        email=user.email,
        username=user.username,  # Set the username here
        hashed_password=hashed_password,
        email_verification_token=verification_token
    )


    db.add(user_in_db)
    db.commit()
    db.refresh(user_in_db)
    return user_in_db


def resetpassword(user: User, db: Session):
    # Generate a verification token
    verification_token = generate_verification_token(user.email)

    # Send a verification email with reset linkhttps://gregniuki-loginauth.hf.space/verify/{verification_token}
    reset_link = f"https://gregniuki-loginauth.hf.space/reset-password?token={verification_token}"
    send_verification_email(user.email, reset_link)

    # Update the user's email verification token
    user.email_verification_token = verification_token
    db.commit()

def get_current_user(token: str = Depends(verify_token)):
    if not token:
        raise HTTPException(status_code=401, detail="Token not valid")
    return token