hermes-mcp/src/multitenancy/platform-health.ts

import redis from '../redis.js';
import { getCredential, type Platform } from './credential-store.js';

const HEALTH_TTL = 600; // 10 minutes

type HealthStatus = 'healthy' | 'expired' | 'disconnected' | 'unknown';

interface PlatformHealth {
  platform: Platform;
  status: HealthStatus;
}

const OAUTH_PLATFORMS: Platform[] = ['linkedin', 'twitter', 'tiktok', 'instagram', 'facebook', 'snapchat'];
const ALL_PLATFORMS: Platform[] = ['email', 'whatsapp', 'linkedin', 'telegram', 'discord', 'instagram', 'twitter', 'tiktok', 'snapchat', 'facebook', 'obsidian'];

async function checkPlatformHealth(customerId: string, platform: Platform): Promise<HealthStatus> {
  const cacheKey = `health:${customerId}:${platform}`;
  const cached = await redis.get(cacheKey);
  if (cached) return cached as HealthStatus;

  const cred = await getCredential(customerId, platform);
  let status: HealthStatus;

  if (!cred) {
    // getCredential returns null for both "not stored" and "expired with no refresh"
    // Check if there was a stored (but expired) credential by looking at the raw key
    const rawKey = `creds:${customerId}:${platform}`;
    const raw = await redis.get(rawKey);
    status = raw ? 'expired' : 'disconnected';
  } else if (OAUTH_PLATFORMS.includes(platform)) {
    // Credential exists and is not expired — probe the API
    status = await probeOAuthPlatform(platform, cred as { accessToken: string });
  } else {
    status = 'healthy';
  }

  await redis.setEx(cacheKey, HEALTH_TTL, status);
  return status;
}

async function probeOAuthPlatform(platform: Platform, cred: { accessToken: string }): Promise<HealthStatus> {
  const probeUrls: Partial<Record<Platform, string>> = {
    linkedin: 'https://api.linkedin.com/v2/userinfo',
    twitter: 'https://api.twitter.com/2/users/me',
    tiktok: 'https://open.tiktokapis.com/v2/user/info/?fields=open_id',
    instagram: 'https://graph.instagram.com/me?fields=id',
    facebook: 'https://graph.facebook.com/me?fields=id',
    snapchat: 'https://adsapi.snapchat.com/v1/me',
  };

  const url = probeUrls[platform];
  if (!url) return 'unknown';

  try {
    const res = await fetch(url, {
      headers: { Authorization: `Bearer ${cred.accessToken}` },
      signal: AbortSignal.timeout(8000),
    });
    return res.ok ? 'healthy' : 'expired';
  } catch {
    return 'unknown';
  }
}

export async function getAllPlatformHealth(customerId: string): Promise<PlatformHealth[]> {
  return Promise.all(
    ALL_PLATFORMS.map(async (platform) => ({
      platform,
      status: await checkPlatformHealth(customerId, platform),
    }))
  );
}