feat(state): replace in-memory Map with SQLite-backed stateService (#59)

- Create src/services/stateService.js with get/set/delete/has API
- Create migration 004_user_states.js (chat_id PK, state_data JSON, updated_at)
- TTL of 24 hours — expired states auto-deleted
- Cleanup job runs every hour (setInterval)
- Replace src/context/userStates.js Map with async stateService proxy
- Add await to all 45 userStates.get/set/delete/has calls across 13 files
- Add initStates() call in index.js startup sequence
- All state survives bot restarts now

18 files changed, 172 insertions, 46 deletions

src/services/stateService.js

@@ -0,0 +1,103 @@
+import db from '../config/database.js';
+import logger from '../utils/logger.js';
+
+const TTL_MS = 24 * 60 * 60 * 1000; // 24 hours
+const CLEANUP_INTERVAL_MS = 60 * 60 * 1000; // 1 hour
+
+let initialized = false;
+
+export async function initStates() {
+    if (initialized) return;
+
+    await db.runAsync(`
+        CREATE TABLE IF NOT EXISTS user_states (
+            chat_id TEXT PRIMARY KEY,
+            state_data TEXT NOT NULL,
+            updated_at INTEGER NOT NULL
+        )
+    `);
+
+    initialized = true;
+    logger.info('user_states table initialized');
+
+    setInterval(cleanExpired, CLEANUP_INTERVAL_MS);
+    cleanExpired();
+}
+
+function serialize(value) {
+    if (value === undefined) return null;
+    return JSON.stringify(value);
+}
+
+function deserialize(json) {
+    if (!json) return undefined;
+    try {
+        return JSON.parse(json);
+    } catch {
+        return undefined;
+    }
+}
+
+export async function get(chatId) {
+    const row = await db.getAsync(
+        'SELECT state_data, updated_at FROM user_states WHERE chat_id = ?',
+        [String(chatId)]
+    );
+
+    if (!row) return undefined;
+
+    if (Date.now() - row.updated_at > TTL_MS) {
+        await db.runAsync('DELETE FROM user_states WHERE chat_id = ?', [String(chatId)]);
+        return undefined;
+    }
+
+    return deserialize(row.state_data);
+}
+
+export async function set(chatId, value) {
+    const data = serialize(value);
+    const now = Date.now();
+
+    await db.runAsync(
+        `INSERT INTO user_states (chat_id, state_data, updated_at)
+         VALUES (?, ?, ?)
+         ON CONFLICT(chat_id) DO UPDATE SET state_data = ?, updated_at = ?`,
+        [String(chatId), data, now, data, now]
+    );
+
+    return value;
+}
+
+export async function del(chatId) {
+    await db.runAsync('DELETE FROM user_states WHERE chat_id = ?', [String(chatId)]);
+}
+
+export async function has(chatId) {
+    const row = await db.getAsync(
+        'SELECT updated_at FROM user_states WHERE chat_id = ?',
+        [String(chatId)]
+    );
+
+    if (!row) return false;
+
+    if (Date.now() - row.updated_at > TTL_MS) {
+        await db.runAsync('DELETE FROM user_states WHERE chat_id = ?', [String(chatId)]);
+        return false;
+    }
+
+    return true;
+}
+
+export async function cleanExpired() {
+    const cutoff = Date.now() - TTL_MS;
+    const result = await db.runAsync(
+        'DELETE FROM user_states WHERE updated_at < ?',
+        [cutoff]
+    );
+    if (result.changes > 0) {
+        logger.info({ expiredCount: result.changes }, 'Cleaned expired user states');
+    }
+}
+
+const userStates = { get, set, delete: del, has, initStates, cleanExpired };
+export default userStates;