Internalize all IM channel implementations

src/channels/feishu/message-utils.mjs

@@ -0,0 +1,50 @@
+export function conversationKey(event) {
+  const chatType = event?.message?.chat_type;
+  if (chatType === 'p2p') {
+    const senderId = event?.sender?.sender_id?.open_id || event?.sender?.sender_id?.user_id;
+    if (!senderId) throw new Error('Feishu p2p event has no sender id');
+    return `p2p:${senderId}`;
+  }
+  const chatId = event?.message?.chat_id;
+  if (!chatId) throw new Error('Feishu group event has no chat id');
+  return `group:${chatId}`;
+}
+
+export function extractText(event) {
+  if (event?.message?.message_type !== 'text') return null;
+  let parsed;
+  try {
+    parsed = JSON.parse(event.message.content);
+  } catch {
+    return null;
+  }
+  let text = typeof parsed.text === 'string' ? parsed.text : '';
+  for (const mention of event.message.mentions ?? []) {
+    if (typeof mention.key === 'string' && mention.key) text = text.replaceAll(mention.key, '');
+  }
+  return text.trim();
+}
+
+export function splitText(text, maxChars = 9000) {
+  if (text.length <= maxChars) return [text];
+  const chunks = [];
+  let remaining = text;
+  while (remaining.length > maxChars) {
+    let splitAt = remaining.lastIndexOf('\n', maxChars);
+    if (splitAt < Math.floor(maxChars * 0.6)) splitAt = maxChars;
+    chunks.push(remaining.slice(0, splitAt));
+    remaining = remaining.slice(splitAt).replace(/^\n+/, '');
+  }
+  if (remaining) chunks.push(remaining);
+  return chunks;
+}
+
+export function isBotSender(event) {
+  return event?.sender?.sender_type === 'bot';
+}
+
+export function isAllowedSender(event, allowedOpenIds) {
+  if (!allowedOpenIds || allowedOpenIds.size === 0) return false;
+  const senderOpenId = event?.sender?.sender_id?.open_id;
+  return typeof senderOpenId === 'string' && allowedOpenIds.has(senderOpenId);
+}