#!/usr/bin/env python3
"""
HTTP health check server
"""

import sys
import json
import threading
from http.server import HTTPServer, BaseHTTPRequestHandler
from datetime import datetime

from logger import log
from config import config


class SilentHTTPServer(HTTPServer):
    """HTTP Server that ignores connection reset errors from scanners"""
    
    def handle_error(self, request, client_address):
        exc_type = sys.exc_info()[0]
        if exc_type in (ConnectionResetError, BrokenPipeError, ConnectionAbortedError):
            pass  # Silently ignore - these are just scanners/health checks disconnecting
        else:
            log(f"Health server error from {client_address[0]}: {sys.exc_info()[1]}", 'WARNING')


class HealthHandler(BaseHTTPRequestHandler):
    """Health check request handler"""
    
    worker = None  # Will be set by start_health_server()
    dynamodb_available = False
    
    def do_GET(self):
        if self.path == '/health' or self.path == '/':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()
            
            status = {
                'status': 'healthy',
                'domains': len(self.worker.queue_urls) if self.worker else 0,
                'domain_list': list(self.worker.queue_urls.keys()) if self.worker else [],
                'dynamodb': self.dynamodb_available,
                'features': {
                    'bounce_rewriting': True,
                    'auto_reply': self.dynamodb_available,
                    'forwarding': self.dynamodb_available,
                    'blocklist': self.dynamodb_available,
                    'lmtp': config.lmtp_enabled
                },
                'timestamp': datetime.utcnow().isoformat()
            }
            self.wfile.write(json.dumps(status, indent=2).encode())
        
        elif self.path == '/domains':
            self.send_response(200)
            self.send_header('Content-Type', 'application/json')
            self.end_headers()
            domain_list = list(self.worker.queue_urls.keys()) if self.worker else []
            self.wfile.write(json.dumps(domain_list).encode())
        
        else:
            self.send_response(404)
            self.end_headers()
    
    def log_message(self, format, *args):
        pass  # Suppress HTTP access logs


def start_health_server(worker, dynamodb_available: bool):
    """
    Start HTTP health check server
    
    Args:
        worker: UnifiedWorker instance
        dynamodb_available: Whether DynamoDB is available
    """
    # Set class attributes for handler
    HealthHandler.worker = worker
    HealthHandler.dynamodb_available = dynamodb_available
    
    server = SilentHTTPServer(('0.0.0.0', config.health_port), HealthHandler)
    thread = threading.Thread(target=server.serve_forever, daemon=True, name='health-server')
    thread.start()
    log(f"Health server on port {config.health_port}")