feat: AI conversation persistence with DB-backed history

.gitignore

@@ -18,6 +18,9 @@ logs/security/
 data/*
 !data/.gitkeep
 
+# Test and coverage outputs
+coverage/
+
 # Verification scripts
 verify-*.js
 VERIFICATION_GUIDE.md

biome.json

@@ -1,25 +1,19 @@
 {
   "$schema": "https://biomejs.dev/schemas/2.3.14/schema.json",
-  "assist": {
-    "actions": {
-      "source": {
-        "organizeImports": "on"
-      }
-    }
+  "files": {
+    "includes": [
+      "src/**/*.js",
+      "tests/**/*.js",
+      "!node_modules/**",
+      "!coverage/**",
+      "!logs/**",
+      "!data/**"
+    ]
   },
   "linter": {
     "enabled": true,
     "rules": {
-      "recommended": true,
-      "correctness": {
-        "noUnusedVariables": "warn",
-        "noUnusedImports": "warn"
-      },
-      "style": {
-        "useConst": "error"
-      },
       "suspicious": {
-        "noVar": "error",
         "noConsole": "error"
       }
     }
@@ -28,17 +22,13 @@
     "enabled": true,
     "indentStyle": "space",
     "indentWidth": 2,
-    "lineWidth": 100,
-    "lineEnding": "lf"
+    "lineWidth": 100
   },
   "javascript": {
     "formatter": {
       "quoteStyle": "single",
       "trailingCommas": "all",
       "semicolons": "always"
     }
-  },
-  "files": {
-    "includes": ["**/*.js", "**/*.json", "**/*.md", "!coverage"]
   }
 }

config.json

@@ -4,7 +4,9 @@
     "model": "claude-sonnet-4-20250514",
     "maxTokens": 1024,
     "systemPrompt": "You are Volvox Bot, the friendly AI assistant for the Volvox developer community Discord server.\n\nYou're witty, snarky (but warm), and deeply knowledgeable about programming, software development, and tech.\n\nKey traits:\n- Helpful but not boring\n- Can roast people lightly when appropriate\n- Enthusiastic about cool tech and projects\n- Supportive of beginners learning to code\n- Concise - this is Discord, not an essay\n\n⚠️ CRITICAL RULES:\n- NEVER type @.everyone or @.here (remove the dots) - these ping hundreds of people\n- NEVER use mass mention pings under any circumstances\n- If you need to address the group, say \"everyone\" or \"folks\" without the @ symbol\n\nKeep responses under 2000 chars. Use Discord markdown when helpful.",
-    "channels": []
+    "channels": [],
+    "historyLength": 20,
+    "historyTTLDays": 30
   },
   "chimeIn": {
     "enabled": false,

package.json

@@ -1,6 +1,6 @@
 {
   "name": "bill-bot",
-  "packageManager": "pnpm@10.29.2",
+  "packageManager": "pnpm@10.28.2",
   "version": "1.0.0",
   "description": "Volvox Discord bot - AI chat, welcome messages, and moderation",
   "main": "src/index.js",
@@ -9,11 +9,12 @@
     "start": "node src/index.js",
     "dev": "node --watch src/index.js",
     "deploy": "node src/deploy-commands.js",
-    "lint": "biome check .",
-    "lint:fix": "biome check . --fix",
-    "format": "biome format . --write",
     "test": "vitest run",
-    "test:coverage": "vitest run --coverage"
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
+    "lint": "biome check .",
+    "lint:fix": "biome check . --write",
+    "format": "biome format . --write"
   },
   "dependencies": {
     "discord.js": "^14.25.1",

src/db.js

@@ -52,10 +52,10 @@ function getSslConfig(connectionString) {
  * @returns {Promise<pg.Pool>} The connection pool
  */
 export async function initDb() {
-  if (pool) return pool;
   if (initializing) {
     throw new Error('initDb is already in progress');
   }
+  if (pool) return pool;
 
   initializing = true;
   try {
@@ -96,6 +96,27 @@ export async function initDb() {
         )
       `);
 
+      await pool.query(`
+        CREATE TABLE IF NOT EXISTS conversations (
+          id SERIAL PRIMARY KEY,
+          channel_id TEXT NOT NULL,
+          role TEXT NOT NULL CHECK (role IN ('user', 'assistant', 'system')),
+          content TEXT NOT NULL,
+          username TEXT,
+          created_at TIMESTAMPTZ DEFAULT NOW()
+        )
+      `);
+
+      await pool.query(`
+        CREATE INDEX IF NOT EXISTS idx_conversations_channel_created
+        ON conversations (channel_id, created_at)
+      `);
+
+      await pool.query(`
+        CREATE INDEX IF NOT EXISTS idx_conversations_created_at
+        ON conversations (created_at)
+      `);
+
       info('Database schema initialized');
     } catch (err) {
       // Clean up the pool so getPool() doesn't return an unusable instance

src/index.js

@@ -18,7 +18,14 @@ import { Client, Collection, Events, GatewayIntentBits } from 'discord.js';
 import { config as dotenvConfig } from 'dotenv';
 import { closeDb, initDb } from './db.js';
 import { error, info, warn } from './logger.js';
-import { getConversationHistory, setConversationHistory } from './modules/ai.js';
+import {
+  getConversationHistory,
+  initConversationHistory,
+  setConversationHistory,
+  setPool,
+  startConversationCleanup,
+  stopConversationCleanup,
+} from './modules/ai.js';
 import { loadConfig } from './modules/config.js';
 import { registerEventHandlers } from './modules/events.js';
 import { HealthMonitor } from './utils/health.js';
@@ -234,23 +241,26 @@ async function gracefulShutdown(signal) {
     }
   }
 
-  // 2. Save state after pending requests complete
+  // 2. Stop conversation cleanup timer
+  stopConversationCleanup();
+
+  // 3. Save state after pending requests complete
   info('Saving conversation state');
   saveState();
 
-  // 3. Close database pool
+  // 4. Close database pool
   info('Closing database connection');
   try {
     await closeDb();
   } catch (err) {
     error('Failed to close database pool', { error: err.message });
   }
 
-  // 4. Destroy Discord client
+  // 5. Destroy Discord client
   info('Disconnecting from Discord');
   client.destroy();
 
-  // 5. Log clean exit
+  // 6. Log clean exit
   info('Shutdown complete');
   process.exit(0);
 }
@@ -275,7 +285,6 @@ process.on('unhandledRejection', (err) => {
     type: typeof err,
   });
 });
-
 // Start bot
 const token = process.env.DISCORD_TOKEN;
 if (!token) {
@@ -294,8 +303,9 @@ if (!token) {
  */
 async function startup() {
   // Initialize database
+  let dbPool = null;
   if (process.env.DATABASE_URL) {
-    await initDb();
+    dbPool = await initDb();
     info('Database initialized');
   } else {
     warn('DATABASE_URL not set — using config.json only (no persistence)');
@@ -305,9 +315,22 @@ async function startup() {
   config = await loadConfig();
   info('Configuration loaded', { sections: Object.keys(config) });
 
-  // Load previous conversation state
+  // Set up AI module's DB pool reference
+  if (dbPool) {
+    setPool(dbPool);
+  }
+
+  // TODO: loadState() is migration-only for file->DB persistence transition.
+  // When DB is available, initConversationHistory() effectively overwrites this state.
+  // Once all environments are DB-backed, remove this call and loadState/saveState helpers.
   loadState();
 
+  // Hydrate conversation history from DB (overwrites file state if DB is available)
+  await initConversationHistory();
+
+  // Start periodic conversation cleanup
+  startConversationCleanup();
+
   // Register event handlers with live config reference
   registerEventHandlers(client, config, healthMonitor);