from datetime import datetime, timedelta
from typing import Optional
from passlib.context import CryptContext
from jose import JWTError, jwt
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from app.config import settings
from app.models import User
from sqlalchemy.orm import Session
from app.database.database import get_db

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
security = HTTPBearer()


def verify_password(plain_password: str, hashed_password: str) -> bool:
    return pwd_context.verify(plain_password, hashed_password)


def get_password_hash(password: str) -> str:
    return pwd_context.hash(password)


def create_access_token(data: dict, expires_delta: Optional[timedelta] = None) -> str:
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(
            minutes=settings.access_token_expire_minutes
        )
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(
        to_encode, settings.jwt_secret_key, algorithm=settings.jwt_algorithm
    )
    return encoded_jwt


def verify_token(token: str) -> Optional[int]:
    try:
        payload = jwt.decode(
            token, settings.jwt_secret_key, algorithms=[settings.jwt_algorithm]
        )
        user_id_str: str = payload.get("sub")
        if user_id_str is None:
            return None
        # Convert string to integer
        user_id = int(user_id_str)
        return user_id
    except JWTError as e:
        return None
    except (ValueError, TypeError) as e:
        return None
    except Exception as e:
        return None


def authenticate_user(db: Session, email: str, password: str) -> Optional[User]:
    user = db.query(User).filter(User.email == email).first()
    if not user or not verify_password(password, user.hashed_password):
        return None
    return user


def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: Session = Depends(get_db),
) -> User:
    token = credentials.credentials
    user_id = verify_token(token)
    if user_id is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid authentication credentials",
        )
    user = db.query(User).filter(User.id == user_id).first()
    if user is None:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="User not found",
        )
    return user


def get_current_admin_user(current_user: User = Depends(get_current_user)) -> User:
    if not current_user.is_admin:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Admin access required",
        )
    return current_user