"""
API Route Dependencies - Supabase Auth Integration
"""
from typing import Generator
from fastapi import Depends, HTTPException, status
from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
from sqlalchemy.orm import Session
from app.core.database import SessionLocal
from app.core.supabase_auth import supabase_auth
from app.models.user import User
import logging

logger = logging.getLogger(__name__)
security = HTTPBearer()


def get_db() -> Generator[Session, None, None]:
    """
    Database session dependency with automatic transaction management
    
    CRITICAL: Sessions MUST be committed or rolled back explicitly.
    If you don't commit, all changes are lost when the session closes.
    """
    db = SessionLocal()
    try:
        yield db
        # AUTO-COMMIT: If endpoint doesn't raise exception, commit the transaction
        db.commit()
    except Exception:
        # AUTO-ROLLBACK: If endpoint raises exception, rollback the transaction
        db.rollback()
        raise
    finally:
        db.close()


async def get_current_user(
    credentials: HTTPAuthorizationCredentials = Depends(security),
    db: Session = Depends(get_db)
) -> User:
    """
    Get current authenticated user from Supabase Auth token
    
    Args:
        credentials: HTTP Bearer token (Supabase JWT)
        db: Database session
        
    Returns:
        Current user
        
    Raises:
        HTTPException: If token is invalid or user not found
    """
    credentials_exception = HTTPException(
        status_code=status.HTTP_401_UNAUTHORIZED,
        detail="Could not validate credentials",
        headers={"WWW-Authenticate": "Bearer"},
    )
    
    try:
        token = credentials.credentials
        
        # Verify token with Supabase and get user
        auth_user = await supabase_auth.get_user(token)
        
        if not auth_user:
            logger.warning("Invalid or expired token")
            raise credentials_exception
        
        user_id = auth_user.id
        
        # Get user from our database
        user = db.query(User).filter(
            User.id == user_id,
            User.deleted_at == None
        ).first()
        
        if user is None:
            logger.warning(f"User not found in database: {user_id}")
            raise credentials_exception
        
        return user
        
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Authentication error: {str(e)}")
        raise credentials_exception


async def get_current_active_user(
    current_user: User = Depends(get_current_user)
) -> User:
    """
    Get current active user

    Args:
        current_user: Current authenticated user

    Returns:
        Current active user

    Raises:
        HTTPException: If user is inactive
    """
    logger.info(f"Checking active user: {current_user.id}, is_active: {current_user.is_active}, type: {type(current_user.is_active)}")

    # Handle None case explicitly
    if current_user.is_active is None:
        logger.warning(f"User {current_user.id} has NULL is_active field - defaulting to False")
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="User account status is undefined"
        )

    if not current_user.is_active:
        logger.warning(f"User {current_user.id} is inactive")
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Inactive user"
        )

    logger.info(f"User {current_user.id} is active - proceeding")
    return current_user


def get_org_scope(user: User) -> dict:
    """
    Get organization scope for org admin users.
    
    Returns dict with org filtering info:
    - is_org_scoped: bool - Whether user is org admin (needs scoping)
    - client_id: UUID or None - Client org to filter by
    - contractor_id: UUID or None - Contractor org to filter by
    
    Platform admins and non-org-admins return is_org_scoped=False
    """
    if user.role in ['client_admin', 'contractor_admin']:
        return {
            'is_org_scoped': True,
            'client_id': user.client_id,
            'contractor_id': user.contractor_id,
            'org_type': 'client' if user.client_id else 'contractor'
        }
    
    return {
        'is_org_scoped': False,
        'client_id': None,
        'contractor_id': None,
        'org_type': None
    }