Initial commit: Telegram bot with Cloudflare Workers

- OpenAI GPT-4o-mini with Function Calling
- Cloudflare D1 for user profiles and message buffer
- Sliding window (3 summaries max) for infinite context
- Tools: weather, search, time, calculator
- Workers AI fallback support
- Webhook security with rate limiting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -0,0 +1,201 @@
+import { Env, TelegramUpdate } from './types';
+import { validateWebhookRequest, checkRateLimit } from './security';
+import { sendMessage, setWebhook, getWebhookInfo, sendChatAction } from './telegram';
+import {
+  addToBuffer,
+  processAndSummarize,
+  generateAIResponse,
+} from './summary-service';
+import { handleCommand } from './commands';
+
+// 사용자 조회/생성
+async function getOrCreateUser(
+  db: D1Database,
+  telegramId: string,
+  firstName: string,
+  username?: string
+): Promise<number> {
+  const existing = await db
+    .prepare('SELECT id FROM users WHERE telegram_id = ?')
+    .bind(telegramId)
+    .first<{ id: number }>();
+
+  if (existing) {
+    // 마지막 활동 시간 업데이트
+    await db
+      .prepare('UPDATE users SET updated_at = CURRENT_TIMESTAMP WHERE id = ?')
+      .bind(existing.id)
+      .run();
+    return existing.id;
+  }
+
+  // 새 사용자 생성
+  const result = await db
+    .prepare('INSERT INTO users (telegram_id, first_name, username) VALUES (?, ?, ?)')
+    .bind(telegramId, firstName, username || null)
+    .run();
+
+  return result.meta.last_row_id as number;
+}
+
+// 메시지 처리
+async function handleMessage(
+  env: Env,
+  update: TelegramUpdate
+): Promise<void> {
+  if (!update.message?.text) return;
+
+  const { message } = update;
+  const chatId = message.chat.id;
+  const chatIdStr = chatId.toString();
+  const text = message.text;
+  const telegramUserId = message.from.id.toString();
+
+  // Rate Limiting 체크
+  if (!checkRateLimit(telegramUserId)) {
+    await sendMessage(
+      env.BOT_TOKEN,
+      chatId,
+      '⚠️ 너무 많은 요청입니다. 잠시 후 다시 시도해주세요.'
+    );
+    return;
+  }
+
+  // 사용자 처리
+  const userId = await getOrCreateUser(
+    env.DB,
+    telegramUserId,
+    message.from.first_name,
+    message.from.username
+  );
+
+  let responseText: string;
+
+  // 명령어 처리
+  if (text.startsWith('/')) {
+    const [command, ...argParts] = text.split(' ');
+    const args = argParts.join(' ');
+    responseText = await handleCommand(env, userId, chatIdStr, command, args);
+  } else {
+    // 타이핑 표시
+    await sendChatAction(env.BOT_TOKEN, chatId, 'typing');
+
+    // 1. 사용자 메시지 버퍼에 추가
+    await addToBuffer(env.DB, userId, chatIdStr, 'user', text);
+
+    try {
+      // 2. AI 응답 생성
+      responseText = await generateAIResponse(env, userId, chatIdStr, text);
+
+      // 3. 봇 응답 버퍼에 추가
+      await addToBuffer(env.DB, userId, chatIdStr, 'bot', responseText);
+
+      // 4. 임계값 도달시 프로필 업데이트
+      const { summarized } = await processAndSummarize(env, userId, chatIdStr);
+
+      if (summarized) {
+        responseText += '\n\n<i>👤 프로필이 업데이트되었습니다.</i>';
+      }
+    } catch (error) {
+      console.error('AI Response error:', error);
+      responseText = `⚠️ AI 응답 생성 중 오류가 발생했습니다.\n\n<code>${String(error)}</code>`;
+    }
+  }
+
+  await sendMessage(env.BOT_TOKEN, chatId, responseText);
+}
+
+export default {
+  // HTTP 요청 핸들러
+  async fetch(request: Request, env: Env): Promise<Response> {
+    const url = new URL(request.url);
+
+    // Webhook 설정 엔드포인트
+    if (url.pathname === '/setup-webhook') {
+      if (!env.BOT_TOKEN) {
+        return Response.json({ error: 'BOT_TOKEN not configured' }, { status: 500 });
+      }
+      if (!env.WEBHOOK_SECRET) {
+        return Response.json({ error: 'WEBHOOK_SECRET not configured' }, { status: 500 });
+      }
+
+      const webhookUrl = `${url.origin}/webhook`;
+      const result = await setWebhook(env.BOT_TOKEN, webhookUrl, env.WEBHOOK_SECRET);
+      return Response.json(result);
+    }
+
+    // Webhook 정보 조회
+    if (url.pathname === '/webhook-info') {
+      if (!env.BOT_TOKEN) {
+        return Response.json({ error: 'BOT_TOKEN not configured' }, { status: 500 });
+      }
+      const result = await getWebhookInfo(env.BOT_TOKEN);
+      return Response.json(result);
+    }
+
+    // 헬스 체크
+    if (url.pathname === '/health') {
+      try {
+        const userCount = await env.DB
+          .prepare('SELECT COUNT(*) as cnt FROM users')
+          .first<{ cnt: number }>();
+
+        const summaryCount = await env.DB
+          .prepare('SELECT COUNT(*) as cnt FROM summaries')
+          .first<{ cnt: number }>();
+
+        return Response.json({
+          status: 'ok',
+          timestamp: new Date().toISOString(),
+          stats: {
+            users: userCount?.cnt || 0,
+            summaries: summaryCount?.cnt || 0,
+          },
+        });
+      } catch (error) {
+        return Response.json({
+          status: 'error',
+          error: String(error),
+        }, { status: 500 });
+      }
+    }
+
+    // Telegram Webhook 처리
+    if (url.pathname === '/webhook') {
+      // 보안 검증
+      const validation = await validateWebhookRequest(request, env);
+
+      if (!validation.valid) {
+        console.error('Webhook validation failed:', validation.error);
+        return new Response(validation.error, { status: 401 });
+      }
+
+      try {
+        await handleMessage(env, validation.update!);
+        return new Response('OK');
+      } catch (error) {
+        console.error('Message handling error:', error);
+        return new Response('Error', { status: 500 });
+      }
+    }
+
+    // 루트 경로
+    if (url.pathname === '/') {
+      return new Response(`
+Telegram Rolling Summary Bot
+
+Endpoints:
+  GET  /health        - Health check
+  GET  /webhook-info  - Webhook status
+  GET  /setup-webhook - Configure webhook
+  POST /webhook       - Telegram webhook (authenticated)
+
+Documentation: https://github.com/your-repo
+      `.trim(), {
+        headers: { 'Content-Type': 'text/plain' },
+      });
+    }
+
+    return new Response('Not Found', { status: 404 });
+  },
+};