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/telegram.ts

@@ -0,0 +1,107 @@
+// Telegram API 메시지 전송
+export async function sendMessage(
+  token: string,
+  chatId: number,
+  text: string,
+  options?: {
+    parse_mode?: 'HTML' | 'Markdown' | 'MarkdownV2';
+    reply_to_message_id?: number;
+    disable_notification?: boolean;
+  }
+): Promise<boolean> {
+  try {
+    const response = await fetch(
+      `https://api.telegram.org/bot${token}/sendMessage`,
+      {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          chat_id: chatId,
+          text,
+          parse_mode: options?.parse_mode || 'HTML',
+          reply_to_message_id: options?.reply_to_message_id,
+          disable_notification: options?.disable_notification,
+        }),
+      }
+    );
+
+    if (!response.ok) {
+      const error = await response.text();
+      console.error('Telegram API error:', error);
+      return false;
+    }
+
+    return true;
+  } catch (error) {
+    console.error('Failed to send message:', error);
+    return false;
+  }
+}
+
+// Webhook 설정 (Secret Token 포함)
+export async function setWebhook(
+  token: string,
+  webhookUrl: string,
+  secretToken: string
+): Promise<{ ok: boolean; description?: string }> {
+  const response = await fetch(
+    `https://api.telegram.org/bot${token}/setWebhook`,
+    {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        url: webhookUrl,
+        secret_token: secretToken,
+        allowed_updates: ['message'],
+        drop_pending_updates: true,
+      }),
+    }
+  );
+
+  return response.json();
+}
+
+// Webhook 정보 조회
+export async function getWebhookInfo(
+  token: string
+): Promise<unknown> {
+  const response = await fetch(
+    `https://api.telegram.org/bot${token}/getWebhookInfo`
+  );
+  return response.json();
+}
+
+// Webhook 삭제
+export async function deleteWebhook(
+  token: string
+): Promise<{ ok: boolean }> {
+  const response = await fetch(
+    `https://api.telegram.org/bot${token}/deleteWebhook`,
+    { method: 'POST' }
+  );
+  return response.json();
+}
+
+// 타이핑 액션 전송
+export async function sendChatAction(
+  token: string,
+  chatId: number,
+  action: 'typing' | 'upload_photo' | 'upload_document' = 'typing'
+): Promise<boolean> {
+  try {
+    const response = await fetch(
+      `https://api.telegram.org/bot${token}/sendChatAction`,
+      {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          chat_id: chatId,
+          action,
+        }),
+      }
+    );
+    return response.ok;
+  } catch {
+    return false;
+  }
+}