from datetime import datetime, timedelta
from typing import Optional
from jose import JWTError, jwt
from passlib.context import CryptContext
from sqlalchemy.orm import Session
import os
import bcrypt as bcrypt_lib

from database.models import User, UserRole
from database.schemas import TokenData  # kept for compatibility

# 환경 변수 - SSO 공유 시크릿 사용 (docker-compose에서 SECRET_KEY=SSO_JWT_SECRET)
SECRET_KEY = os.getenv("SECRET_KEY", "your-secret-key-here")
ALGORITHM = os.getenv("ALGORITHM", "HS256")
ACCESS_TOKEN_EXPIRE_MINUTES = int(os.getenv("ACCESS_TOKEN_EXPIRE_MINUTES", "10080"))  # 7 days

# 비밀번호 암호화 (pbkdf2_sha256 - 로컬 인증용)
pwd_context = CryptContext(
    schemes=["pbkdf2_sha256"],
    deprecated="auto"
)

def verify_password(plain_password: str, hashed_password: str) -> bool:
    """비밀번호 검증 - bcrypt + pbkdf2_sha256 둘 다 지원 (SSO 호환)"""
    if not plain_password or not hashed_password:
        return False

    # bcrypt 형식 ($2b$ 또는 $2a$)
    if hashed_password.startswith(("$2b$", "$2a$")):
        try:
            return bcrypt_lib.checkpw(
                plain_password.encode('utf-8'),
                hashed_password.encode('utf-8')
            )
        except Exception:
            return False

    # pbkdf2_sha256 형식 (passlib)
    try:
        return pwd_context.verify(plain_password, hashed_password)
    except Exception:
        return False

def get_password_hash(password: str) -> str:
    """비밀번호 해시 생성 (pbkdf2_sha256)"""
    return pwd_context.hash(password)

def create_access_token(data: dict, expires_delta: Optional[timedelta] = None):
    to_encode = data.copy()
    if expires_delta:
        expire = datetime.utcnow() + expires_delta
    else:
        expire = datetime.utcnow() + timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    to_encode.update({"exp": expire})
    encoded_jwt = jwt.encode(to_encode, SECRET_KEY, algorithm=ALGORITHM)
    return encoded_jwt

def verify_token(token: str, credentials_exception):
    """JWT 토큰 검증 - SSO 토큰 전체 페이로드 반환"""
    try:
        payload = jwt.decode(token, SECRET_KEY, algorithms=[ALGORITHM])
        username: str = payload.get("sub")
        if username is None:
            raise credentials_exception
        return payload
    except JWTError:
        raise credentials_exception

def authenticate_user(db: Session, username: str, password: str):
    user = db.query(User).filter(User.username == username).first()
    if not user:
        return False
    if not verify_password(password, user.hashed_password):
        return False
    return user

def create_admin_user(db: Session):
    """관리자 계정 확인 (SSO에서 관리, 여기서는 조회만)"""
    admin_username = os.getenv("ADMIN_USERNAME", "hyungi")

    existing_admin = db.query(User).filter(User.username == admin_username).first()
    if existing_admin:
        print(f"관리자 계정 확인됨: {admin_username} (role: {existing_admin.role.value})")
    else:
        print(f"경고: 관리자 계정이 sso_users에 없습니다: {admin_username}")