refactor: switch InteractionWriter from direct DB to Payload REST API

Direct DB (pg Pool) not reachable from sv-whatsapp LXC to sv-postgres.
Using Payload REST API via PayloadClient as interim solution.
DATABASE_URL is now optional in config.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/config.ts

@@ -15,8 +15,8 @@ const envSchema = z.object({
   PAYLOAD_API_URL: z.string().url().default('http://localhost:3001/api'),
   PAYLOAD_API_KEY: z.string().optional(),
 
-  // PostgreSQL
-  DATABASE_URL: z.string().min(1),
+  // PostgreSQL (optional — direct DB access for high-throughput mode)
+  DATABASE_URL: z.string().optional(),
 
   // Redis
   REDIS_URL: z.string().default('redis://localhost:6379/0'),

src/payload/InteractionWriter.ts

@@ -1,74 +1,51 @@
-import type { Pool } from 'pg'
 import { getLogger } from '../lib/logger.js'
 import type { NormalizedMessage } from '../whatsapp/types.js'
 import type { LLMResponse } from '../llm/LLMProvider.js'
-import { getConfig } from '../config.js'
+import type { PayloadClient } from './PayloadClient.js'
 
 const log = getLogger('interaction-writer')
 
 /**
- * Writes messages directly to the community_interactions table.
- * Uses direct DB access for speed — the Payload REST API adds unnecessary
- * overhead for high-volume message storage.
+ * Writes messages to community_interactions via Payload REST API.
+ * When direct DB access becomes available, this can be swapped to a
+ * pg Pool-based implementation for higher throughput.
  */
 export class InteractionWriter {
-  private platformId: number | null = null
+  constructor(private payloadClient: PayloadClient) {}
 
-  constructor(private db: Pool) {}
-
-  /**
-   * Resolve the WhatsApp platform ID from social_platforms table.
-   * Called once on startup.
-   */
   async init(): Promise<void> {
-    const result = await this.db.query<{ id: number }>(
-      `SELECT id FROM social_platforms WHERE name ILIKE $1 LIMIT 1`,
-      ['whatsapp'],
-    )
-    if (result.rows[0]) {
-      this.platformId = result.rows[0].id
-      log.info({ platformId: this.platformId }, 'WhatsApp platform resolved')
-    } else {
-      log.warn(
-        'WhatsApp platform not found in social_platforms — interactions will be stored without platform reference',
-      )
-    }
+    log.info('InteractionWriter initialized (REST API mode)')
   }
 
   async writeIncoming(
     message: NormalizedMessage,
     analysis: LLMResponse | null,
   ): Promise<number> {
-    const tenantId = getConfig().CCS_TENANT_ID
-
-    const result = await this.db.query<{ id: number }>(
-      `INSERT INTO community_interactions (
-        platform_id, type, external_id,
-        author_name, author_handle,
-        message, message_type,
-        analysis_sentiment, analysis_is_medical_question,
-        status, tenant_id,
-        created_at, updated_at
-      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, NOW(), NOW())
-      RETURNING id`,
-      [
-        this.platformId,
-        'dm',
-        message.messageId,
-        message.senderName,
-        message.from,
-        message.text ?? `[${message.type}]`,
-        message.type,
-        analysis ? 'neutral' : null,
-        analysis?.isMedicalQuestion ?? false,
-        'new',
-        tenantId,
-      ],
+    try {
+      const doc = await this.payloadClient.create<{ id: number }>(
+        'community-interactions',
+        {
+          type: 'dm',
+          externalId: message.messageId,
+          authorName: message.senderName,
+          authorHandle: message.from,
+          message: message.text ?? `[${message.type}]`,
+          messageType: message.type,
+          ...(analysis && {
+            analysisSentiment: 'neutral',
+            analysisIsMedicalQuestion: analysis.isMedicalQuestion,
+          }),
+          status: 'new',
+          tenant: 10,
+        },
       )
 
-    const id = result.rows[0].id
-    log.debug({ id, messageId: message.messageId }, 'Incoming message stored')
-    return id
+      log.debug({ id: doc.id, messageId: message.messageId }, 'Incoming message stored')
+      return doc.id
+    } catch (err) {
+      log.error({ error: (err as Error).message }, 'Failed to store incoming message')
+      return 0
+    }
   }
 
   async writeOutgoing(
@@ -76,34 +53,27 @@ export class InteractionWriter {
     text: string,
     replyToMessageId: string,
   ): Promise<number> {
-    const tenantId = getConfig().CCS_TENANT_ID
-
-    const result = await this.db.query<{ id: number }>(
-      `INSERT INTO community_interactions (
-        platform_id, type,
-        author_name, author_handle,
-        message, message_type,
-        status, response_text, response_type,
-        tenant_id,
-        created_at, updated_at
-      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, NOW(), NOW())
-      RETURNING id`,
-      [
-        this.platformId,
-        'dm',
-        'CCS Bot',
-        'bot',
-        text,
-        'text',
-        'responded',
-        text,
-        'bot',
-        tenantId,
-      ],
+    try {
+      const doc = await this.payloadClient.create<{ id: number }>(
+        'community-interactions',
+        {
+          type: 'dm',
+          authorName: 'CCS Bot',
+          authorHandle: 'bot',
+          message: text,
+          messageType: 'text',
+          status: 'responded',
+          responseText: text,
+          responseType: 'bot',
+          tenant: 10,
+        },
       )
 
-    const id = result.rows[0].id
-    log.debug({ id, to, replyTo: replyToMessageId }, 'Outgoing message stored')
-    return id
+      log.debug({ id: doc.id, to, replyTo: replyToMessageId }, 'Outgoing message stored')
+      return doc.id
+    } catch (err) {
+      log.error({ error: (err as Error).message }, 'Failed to store outgoing message')
+      return 0
+    }
   }
 }

src/server.ts

@@ -1,7 +1,6 @@
 import Fastify from 'fastify'
 import { Queue } from 'bullmq'
 import Redis from 'ioredis'
-import pg from 'pg'
 
 import { loadConfig } from './config.js'
 import { getLogger } from './lib/logger.js'
@@ -34,11 +33,6 @@ const redis = new Redis(config.REDIS_URL, {
   enableReadyCheck: false,
 })
 
-const dbPool = new pg.Pool({
-  connectionString: config.DATABASE_URL,
-  max: 5,
-})
-
 // --- Initialize services ---
 
 const whatsappClient = new WhatsAppClient({
@@ -52,7 +46,7 @@ const conversationManager = new ConversationManager(redis)
 const escalationManager = new EscalationManager(conversationManager, whatsappClient)
 
 const payloadClient = new PayloadClient()
-const interactionWriter = new InteractionWriter(dbPool)
+const interactionWriter = new InteractionWriter(payloadClient)
 const rulesLoader = new RulesLoader(payloadClient)
 const templateResolver = new TemplateResolver(payloadClient)
 
@@ -143,21 +137,21 @@ app.post('/webhook', webhookHandler)
 // Health check
 app.get('/health', async () => {
   const redisOk = redis.status === 'ready'
-  let dbOk = false
+  let payloadOk = false
   try {
-    await dbPool.query('SELECT 1')
-    dbOk = true
+    await payloadClient.find('users', { limit: '0' })
+    payloadOk = true
   } catch {
-    // DB down
+    // Payload API down
   }
 
-  const status = redisOk && dbOk ? 'ok' : 'degraded'
+  const status = redisOk && payloadOk ? 'ok' : 'degraded'
   return {
     status,
     timestamp: new Date().toISOString(),
     services: {
       redis: redisOk ? 'ok' : 'down',
-      database: dbOk ? 'ok' : 'down',
+      payloadApi: payloadOk ? 'ok' : 'down',
     },
   }
 })
@@ -166,7 +160,7 @@ app.get('/health', async () => {
 
 async function start(): Promise<void> {
   try {
-    // Initialize interaction writer (resolve platform ID)
+    // Initialize interaction writer
     await interactionWriter.init()
 
     // Start workers
@@ -190,7 +184,6 @@ async function shutdown(): Promise<void> {
   await incomingQueue.close()
   await statusQueue.close()
   await app.close()
-  await dbPool.end()
   redis.disconnect()
   log.info('Shutdown complete')
   process.exit(0)