whatsapp-bot/src/payload/TemplateResolver.ts

import { getLogger } from '../lib/logger.js'
import type { PayloadClient } from './PayloadClient.js'
import { getConfig } from '../config.js'
import { DEFAULT_HEALTHCARE_PROMPT } from '../llm/HealthcarePrompt.js'

const log = getLogger('template-resolver')

interface CommunityTemplate {
  id: number
  name: string
  category: string
  content: string
  tenant?: number | { id: number }
}

const TEMPLATE_CACHE_TTL = 600_000 // 10 minutes

export class TemplateResolver {
  private systemPromptCache: string | null = null
  private lastFetch = 0

  constructor(private payloadClient: PayloadClient) {}

  async getSystemPrompt(): Promise<string> {
    const now = Date.now()
    if (now - this.lastFetch < TEMPLATE_CACHE_TTL && this.systemPromptCache) {
      return this.systemPromptCache
    }

    try {
      const tenantId = getConfig().CCS_TENANT_ID
      const result = await this.payloadClient.find<CommunityTemplate>(
        'community-templates',
        {
          'where[category][equals]': 'whatsapp_system_prompt',
          'where[tenant][equals]': tenantId,
          limit: '1',
        },
      )

      if (result.docs.length > 0) {
        this.systemPromptCache = result.docs[0].content
        this.lastFetch = now
        log.info('System prompt loaded from CMS')
        return this.systemPromptCache
      }
    } catch (err) {
      log.error(
        { error: (err as Error).message },
        'Failed to load system prompt from CMS',
      )
    }

    // Fallback to hardcoded prompt
    log.info('Using default healthcare prompt')
    return DEFAULT_HEALTHCARE_PROMPT
  }

  async resolveTemplate(
    category: string,
    name?: string,
  ): Promise<string | null> {
    try {
      const tenantId = getConfig().CCS_TENANT_ID
      const query: Record<string, unknown> = {
        'where[category][equals]': category,
        'where[tenant][equals]': tenantId,
        limit: '1',
      }
      if (name) {
        query['where[name][equals]'] = name
      }

      const result =
        await this.payloadClient.find<CommunityTemplate>(
          'community-templates',
          query,
        )

      return result.docs[0]?.content ?? null
    } catch (err) {
      log.error(
        { category, name, error: (err as Error).message },
        'Failed to resolve template',
      )
      return null
    }
  }
}