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

settings = get_settings()
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()
    expire = datetime.utcnow() + (expires_delta or timedelta(minutes=settings.JWT_ACCESS_TOKEN_EXPIRE_MINUTES))
    to_encode.update({"exp": expire, "type": "access"})
    return jwt.encode(to_encode, settings.JWT_SECRET, algorithm=settings.JWT_ALGORITHM)


def create_refresh_token(data: dict) -> str:
    to_encode = data.copy()
    expire = datetime.utcnow() + timedelta(days=settings.JWT_REFRESH_TOKEN_EXPIRE_DAYS)
    to_encode.update({"exp": expire, "type": "refresh"})
    return jwt.encode(to_encode, settings.JWT_SECRET, algorithm=settings.JWT_ALGORITHM)


def decode_token(token: str) -> dict:
    try:
        payload = jwt.decode(token, settings.JWT_SECRET, algorithms=[settings.JWT_ALGORITHM])
        return payload
    except JWTError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid token",
            headers={"WWW-Authenticate": "Bearer"},
        )


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: Session = Depends(get_db),
) -> User:
    token = credentials.credentials
    payload = decode_token(token)

    if payload.get("type") != "access":
        raise HTTPException(status_code=401, detail="Invalid token type")

    user_id = payload.get("sub")
    if not user_id:
        raise HTTPException(status_code=401, detail="Invalid token")

    user = db.query(User).filter(User.id == user_id).first()
    if not user or not user.is_active:
        raise HTTPException(status_code=401, detail="User not found or inactive")

    return user


def require_role(*roles):
    async def role_checker(current_user: User = Depends(get_current_user)):
        if current_user.role not in roles:
            raise HTTPException(status_code=403, detail="Insufficient permissions")
        return current_user
    return role_checker