#!/usr/bin/env python3
"""
Bounce detection and header rewriting
"""

from typing import Tuple, Any

from logger import log
from aws.dynamodb_handler import DynamoDBHandler


class BounceHandler:
    """Handles bounce detection and header rewriting"""
    
    def __init__(self, dynamodb: DynamoDBHandler):
        self.dynamodb = dynamodb
    
    @staticmethod
    def is_ses_bounce_notification(parsed_email) -> bool:
        """Check if email is from SES MAILER-DAEMON"""
        from_header = (parsed_email.get('From') or '').lower()
        return 'mailer-daemon@' in from_header and 'amazonses.com' in from_header
    
    def apply_bounce_logic(
        self, 
        parsed, 
        subject: str, 
        worker_name: str = 'unified'
    ) -> Tuple[Any, bool]:
        """
        Check for SES Bounce, lookup in DynamoDB and rewrite headers
        
        Args:
            parsed: Parsed email message object
            subject: Email subject
            worker_name: Worker name for logging
            
        Returns:
            Tuple of (parsed_email_object, was_modified_bool)
        """
        if not self.is_ses_bounce_notification(parsed):
            return parsed, False

        log("🔍 Detected SES MAILER-DAEMON bounce notification", 'INFO', worker_name)
        
        # Extract Message-ID from header
        message_id = (parsed.get('Message-ID') or '').strip('<>').split('@')[0]
        
        if not message_id:
            log("⚠ Could not extract Message-ID from bounce notification", 'WARNING', worker_name)
            return parsed, False

        log(f"  Looking up Message-ID: {message_id}", 'INFO', worker_name)
        
        # Lookup in DynamoDB
        bounce_info = self.dynamodb.get_bounce_info(message_id, worker_name)
        
        if not bounce_info:
            return parsed, False

        # Bounce Info ausgeben
        original_source = bounce_info['original_source']
        bounced_recipients = bounce_info['bouncedRecipients']
        bounce_type = bounce_info['bounceType']
        bounce_subtype = bounce_info['bounceSubType']
        
        log(f"✓ Found bounce info:", 'INFO', worker_name)
        log(f"  Original sender: {original_source}", 'INFO', worker_name)
        log(f"  Bounce type: {bounce_type}/{bounce_subtype}", 'INFO', worker_name)
        log(f"  Bounced recipients: {bounced_recipients}", 'INFO', worker_name)
        
        if bounced_recipients:
            new_from = bounced_recipients[0]
            
            # Rewrite Headers
            parsed['X-Original-SES-From'] = parsed.get('From', '')
            parsed['X-Bounce-Type'] = f"{bounce_type}/{bounce_subtype}"
            parsed.replace_header('From', new_from)
            
            if not parsed.get('Reply-To'):
                parsed['Reply-To'] = new_from
            
            # Subject anpassen
            if 'delivery status notification' in subject.lower() or 'thanks for your submission' in subject.lower():
                parsed.replace_header('Subject', f"Delivery Status: {new_from}")
            
            log(f"✓ Rewritten FROM: {new_from}", 'SUCCESS', worker_name)
            return parsed, True
        
        log("⚠ No bounced recipients found in bounce info", 'WARNING', worker_name)
        return parsed, False