#!/usr/bin/env node
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { SendGridMCPServer } from './server.js';

// Validate environment
const SENDGRID_API_KEY = process.env.SENDGRID_API_KEY;

if (!SENDGRID_API_KEY) {
  console.error('❌ ERROR: SENDGRID_API_KEY environment variable is required');
  console.error('');
  console.error('Get your API key from:');
  console.error('  1. Log in to SendGrid: https://app.sendgrid.com/');
  console.error('  2. Navigate to Settings > API Keys');
  console.error('  3. Create a new API key with Full Access or Mail Send permissions');
  console.error('  4. Copy the key and set: export SENDGRID_API_KEY=your_key_here');
  console.error('');
  console.error('Required permissions:');
  console.error('  - Mail Send (for transactional emails)');
  console.error('  - Marketing Campaigns (for campaigns, lists, contacts)');
  console.error('  - Template Engine (for templates)');
  console.error('  - Suppressions (for bounce/spam management)');
  process.exit(1);
}

// Create server instance
const server = new SendGridMCPServer({
  apiKey: SENDGRID_API_KEY,
});

// Graceful shutdown
let isShuttingDown = false;

const shutdown = async (signal: string) => {
  if (isShuttingDown) return;
  isShuttingDown = true;
  
  console.error(`\n📡 Received ${signal}, shutting down SendGrid MCP server...`);
  
  try {
    await server.close();
    console.error('✅ Server closed gracefully');
    process.exit(0);
  } catch (error) {
    console.error('❌ Error during shutdown:', error);
    process.exit(1);
  }
};

process.on('SIGINT', () => shutdown('SIGINT'));
process.on('SIGTERM', () => shutdown('SIGTERM'));

// Start server
const transport = new StdioServerTransport();
server.connect(transport).catch((error) => {
  console.error('❌ Failed to start SendGrid MCP server:', error);
  process.exit(1);
});

console.error('🚀 SendGrid MCP Server running on stdio');
console.error('📧 Ready to handle email operations');