From 80a5f3bf425fc2b4ea2f78d33266ac4b2792763e Mon Sep 17 00:00:00 2001
From: Emanuel Almeida <emanuel@descomplicar.pt>
Date: Thu, 23 Apr 2026 01:19:21 +0100
Subject: [PATCH] feat(observabilidade): watcher chokidar incremental

---
 api/scripts/sessions-indexer.ts  |  7 ++---
 api/services/sessions/watcher.ts | 49 ++++++++++++++++++++++++++++----
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/api/scripts/sessions-indexer.ts b/api/scripts/sessions-indexer.ts
index 6beff24..fb43786 100644
--- a/api/scripts/sessions-indexer.ts
+++ b/api/scripts/sessions-indexer.ts
@@ -9,7 +9,7 @@
  * Env:
  *   OBSERVABILIDADE_DB  Override ao caminho da BD SQLite
  */
-import { indexAll, DEFAULT_DB_PATH } from '../services/sessions/indexer.js'
+import { indexAll, DEFAULT_DB_PATH, PROJECTS_ROOT } from '../services/sessions/indexer.js'
 import { startWatcher } from '../services/sessions/watcher.js'
 
 async function main(): Promise<void> {
@@ -24,11 +24,10 @@ async function main(): Promise<void> {
   console.log(`[indexer] modo=${mode} db=${dbPath}`)
 
   if (mode === '--watch') {
-    console.log(`[indexer] watch mode em ${dbPath}`)
+    console.log(`[indexer] watch mode em ${PROJECTS_ROOT} -> ${dbPath}`)
     await indexAll({ dbPath })
     await startWatcher(dbPath)
-    console.log('[indexer] watcher ainda não implementado (ver Task 8) — saída limpa')
-    process.exit(0)
+    return
   }
 
   const start = Date.now()
diff --git a/api/services/sessions/watcher.ts b/api/services/sessions/watcher.ts
index 679361d..57e7d5d 100644
--- a/api/services/sessions/watcher.ts
+++ b/api/services/sessions/watcher.ts
@@ -1,7 +1,44 @@
-/**
- * Stub — implementação real chega em Task 8 (chokidar).
- * Devolve imediatamente; o CLI imprime aviso e termina com exit 0.
- */
-export async function startWatcher(_dbPath: string): Promise<void> {
-  return
+import chokidar from 'chokidar'
+import { openSessionsDb } from './db.js'
+import { indexFile, PROJECTS_ROOT } from './indexer.js'
+
+export async function startWatcher(dbPath: string): Promise<void> {
+  const db = openSessionsDb(dbPath)
+  const watcher = chokidar.watch(`${PROJECTS_ROOT}/**/*.jsonl`, {
+    persistent: true,
+    ignoreInitial: true,
+    awaitWriteFinish: { stabilityThreshold: 2000, pollInterval: 500 },
+  })
+
+  async function reindex(path: string): Promise<void> {
+    try {
+      await indexFile(db, path)
+      console.log(`[watcher] indexed ${path}`)
+    } catch (err) {
+      console.error(`[watcher] erro ${path}:`, err)
+    }
+  }
+
+  watcher
+    .on('add', reindex)
+    .on('change', reindex)
+    .on('unlink', (path) => {
+      db.deleteByJsonlPath(path)
+      console.log(`[watcher] removed ${path}`)
+    })
+    .on('error', (err) => console.error('[watcher] error:', err))
+
+  console.log('[watcher] pronto')
+
+  // Registar handler SIGTERM/SIGINT para fechar DB limpa (evita WAL corruption em Task 9 systemd restart)
+  const cleanup = async (): Promise<void> => {
+    console.log('[watcher] SIGTERM/SIGINT — a fechar watcher e DB')
+    await watcher.close()
+    db.close()
+    process.exit(0)
+  }
+  process.on('SIGTERM', () => { void cleanup() })
+  process.on('SIGINT', () => { void cleanup() })
+
+  return new Promise(() => {}) // nunca resolve — processo mantém-se vivo
 }