from typing import Dict, Any, List, Optional, Callable
from fastapi import APIRouter, Depends, HTTPException, Query, Body, Header, Request
from core.integration_registry import IntegrationRegistry
from core.database import get_db
from sqlalchemy.orm import Session
import hmac
import hashlib
import base64
import logging

logger = logging.getLogger(__name__)

def get_webhook_registry(db: Session = Depends(get_db)) -> IntegrationRegistry:
    """Dependency for obtaining the IntegrationRegistry for webhook processing."""
    return IntegrationRegistry(db)

def verify_hmac_signature(data: bytes, signature: str, secret: str, algorithm=hashlib.sha256) -> bool:
    """Utility to verify HMAC signatures for incoming webhooks."""
    if not secret or not signature:
        return False
        
    digest = hmac.new(secret.encode('utf-8'), data, algorithm).digest()
    
    # Handle base64 encoded signatures if needed
    try:
        if len(signature) > 64: # Likely base64
            computed = base64.b64encode(digest).decode('utf-8')
        else:
            computed = hmac.new(secret.encode('utf-8'), data, algorithm).hexdigest()
            
        return hmac.compare_digest(computed, signature)
    except Exception as e:
        logger.error(f"HMAC verification failed: {e}")
        return False

# Re-exporting for standard route usage
__all__ = ["get_webhook_registry", "verify_hmac_signature"]