from datetime import datetime, timedelta
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.database import get_db
import os

_DEFAULT_KEY = "asim-scheduling-secret-key-2026"
SECRET_KEY = os.getenv("SECRET_KEY", _DEFAULT_KEY)

if SECRET_KEY == _DEFAULT_KEY:
    import warnings
    warnings.warn(
        "\n⚠️  SECRET_KEY tidak diset di environment!\n"
        "   Token JWT menggunakan kunci default yang tidak aman.\n"
        "   Buat file .env dan set: SECRET_KEY=<random-string-panjang>\n",
        stacklevel=1,
    )

ALGORITHM = "HS256"
ACCESS_TOKEN_EXPIRE_MINUTES = 60 * 24  # 24 jam

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")
bearer_scheme = 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) -> str:
    to_encode = data.copy()
    expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    return jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)


def decode_token(token: str) -> dict:
    return jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])


def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(bearer_scheme),
    db: Session = Depends(get_db),
):
    """Dependency: pastikan request punya token JWT yang valid."""
    from app.models.user import User
    try:
        payload = decode_token(credentials.credentials)
        user_id = int(payload.get("sub"))
    except Exception:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Token tidak valid atau sudah kadaluarsa",
            headers={"WWW-Authenticate": "Bearer"},
        )
    user = db.query(User).filter(User.id == user_id).first()
    if not user or not user.is_active:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Akun tidak aktif atau tidak ditemukan",
            headers={"WWW-Authenticate": "Bearer"},
        )
    return user


def require_pengurus(current_user=Depends(get_current_user)):
    """Dependency: hanya pengurus atau super_admin yang boleh akses."""
    if current_user.role not in ("pengurus", "super_admin"):
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Akses ditolak: hanya untuk pengurus",
        )
    return current_user


def require_super_admin(current_user=Depends(get_current_user)):
    """Dependency: hanya super_admin yang boleh akses."""
    if current_user.role != "super_admin":
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Akses ditolak: hanya untuk super admin",
        )
    return current_user