from typing import Generator, Optional
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session
from jose import JWTError
from app.database import SessionLocal
from app.crud import user_crud
from app.core.security import verify_token
from app.models import User, UserSession
from app.core.config import settings
import logging

logger = logging.getLogger(__name__)

security = HTTPBearer(auto_error=False)


def get_db() -> Generator:
    """
    دریافت connection به پایگاه داده
    """
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()


async def get_current_user(
    credentials: Optional[HTTPAuthorizationCredentials] = Depends(security),
    db: Session = Depends(get_db)
) -> User:
    """
    دریافت کاربر جاری از توکن
    """
    if not credentials:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="اعتبارسنجی مورد نیاز است",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    try:
        # بررسی توکن
        payload = verify_token(credentials.credentials)
        if not payload:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="توکن نامعتبر",
                headers={"WWW-Authenticate": "Bearer"},
            )
        
        user_id: int = payload.get("sub")
        session_id: str = payload.get("session_id")
        
        if user_id is None or session_id is None:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="توکن نامعتبر",
                headers={"WWW-Authenticate": "Bearer"},
            )
        
        # بررسی سشن
        session = user_crud.validate_session(db, session_id)
        if not session:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="سشن منقضی شده است",
                headers={"WWW-Authenticate": "Bearer"},
            )
        
        # دریافت کاربر
        user = user_crud.get_by_id(db, user_id=user_id)
        if not user or not user.is_active:
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="کاربر غیرفعال است",
                headers={"WWW-Authenticate": "Bearer"},
            )
        
        return user
    
    except JWTError:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="خطا در اعتبارسنجی",
            headers={"WWW-Authenticate": "Bearer"},
        )


async def get_current_active_superuser(
    current_user: User = Depends(get_current_user),
) -> User:
    """
    بررسی ادمین بودن کاربر
    """
    if not current_user.is_superuser:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="دسترسی محدود",
        )
    return current_user


def get_client_info(request) -> dict:
    """
    دریافت اطلاعات کلاینت
    """
    return {
        "ip_address": request.client.host if request.client else "unknown",
        "user_agent": request.headers.get("user-agent", "unknown"),
    }