Include missed messages when catching up the agent

When a triggered message comes in, fetch all messages in that chat
since the last agent interaction and include them in the prompt.
Each message is formatted with timestamp and sender.

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

src/index.ts

@@ -20,7 +20,7 @@ import {
   CLEAR_COMMAND
 } from './config.js';
 import { RegisteredGroup, Session, NewMessage } from './types.js';
-import { initDatabase, storeMessage, getNewMessages } from './db.js';
+import { initDatabase, storeMessage, getNewMessages, getMessagesSince } from './db.js';
 
 const logger = pino({
   level: process.env.LOG_LEVEL || 'info',
@@ -31,6 +31,7 @@ let sock: WASocket;
 let lastTimestamp = '';
 let sessions: Session = {};
 let registeredGroups: Record<string, RegisteredGroup> = {};
+let lastAgentTimestamp: Record<string, string> = {};
 
 function loadJson<T>(filePath: string, defaultValue: T): T {
   try {
@@ -50,15 +51,16 @@ function saveJson(filePath: string, data: unknown): void {
 
 function loadState(): void {
   const statePath = path.join(DATA_DIR, 'router_state.json');
-  const state = loadJson<{ last_timestamp?: string }>(statePath, {});
+  const state = loadJson<{ last_timestamp?: string; last_agent_timestamp?: Record<string, string> }>(statePath, {});
   lastTimestamp = state.last_timestamp || '';
+  lastAgentTimestamp = state.last_agent_timestamp || {};
   sessions = loadJson(path.join(DATA_DIR, 'sessions.json'), {});
   registeredGroups = loadJson(path.join(DATA_DIR, 'registered_groups.json'), {});
   logger.info({ groupCount: Object.keys(registeredGroups).length }, 'State loaded');
 }
 
 function saveState(): void {
-  saveJson(path.join(DATA_DIR, 'router_state.json'), { last_timestamp: lastTimestamp });
+  saveJson(path.join(DATA_DIR, 'router_state.json'), { last_timestamp: lastTimestamp, last_agent_timestamp: lastAgentTimestamp });
   saveJson(path.join(DATA_DIR, 'sessions.json'), sessions);
 }
 
@@ -86,11 +88,31 @@ async function processMessage(msg: NewMessage): Promise<void> {
 
   if (!TRIGGER_PATTERN.test(content)) return;
 
-  const prompt = content.replace(TRIGGER_PATTERN, '').trim();
-  if (!prompt) return;
+  const userMessage = content.replace(TRIGGER_PATTERN, '').trim();
+  if (!userMessage) return;
 
-  logger.info({ group: group.name, prompt: prompt.slice(0, 50) }, 'Processing message');
+  // Get messages since last agent interaction to catch up the session
+  const sinceTimestamp = lastAgentTimestamp[msg.chat_jid] || '';
+  const missedMessages = getMessagesSince(msg.chat_jid, sinceTimestamp);
+
+  // Build prompt with conversation history
+  let prompt = '';
+  for (const m of missedMessages) {
+    if (m.id === msg.id) continue; // Skip current message, we'll add it at the end
+    const time = new Date(m.timestamp).toLocaleTimeString();
+    const sender = m.sender.split('@')[0]; // Extract phone number or name
+    prompt += `[${time}] ${sender}: ${m.content}\n`;
+  }
+  const time = new Date(msg.timestamp).toLocaleTimeString();
+  const sender = msg.sender.split('@')[0];
+  prompt += `[${time}] ${sender}: ${userMessage}`;
+
+  logger.info({ group: group.name, messageCount: missedMessages.length }, 'Processing message');
   const response = await runAgent(group, prompt);
+
+  // Update last agent timestamp
+  lastAgentTimestamp[msg.chat_jid] = msg.timestamp;
+
   if (response) {
     await sendMessage(msg.chat_jid, `${ASSISTANT_NAME}: ${response}`);
   }