From 6d1f4a996d25f93a6b5a0c5f8f605f58048d3e2f Mon Sep 17 00:00:00 2001
From: Samira Mokaram <samiram@spotify.com>
Date: Fri, 23 Oct 2020 13:14:08 +0200
Subject: [PATCH] fetching data from pagerduty endpoint in interval

---
 .../pagerduty-backend/src/service/router.ts   | 95 ++++++++++++++++++-
 1 file changed, 92 insertions(+), 3 deletions(-)

diff --git a/plugins/pagerduty-backend/src/service/router.ts b/plugins/pagerduty-backend/src/service/router.ts
index eb7cc734c2..192a22019a 100644
--- a/plugins/pagerduty-backend/src/service/router.ts
+++ b/plugins/pagerduty-backend/src/service/router.ts
@@ -14,11 +14,79 @@
  * limitations under the License.
  */
 
-import { errorHandler } from '@backstage/backend-common';
+import { errorHandler, useHotCleanup } from '@backstage/backend-common';
 import { Config } from '@backstage/config';
 import express from 'express';
 import Router from 'express-promise-router';
 import { Logger } from 'winston';
+import fetch from 'node-fetch';
+
+const router = Router();
+const API_URL = 'https://api.pagerduty.com';
+const EVENTS_API_URL = 'https://events.pagerduty.com/v2';
+
+type Options = {
+  method: string;
+  headers: {
+    'Content-Type': string;
+    Accept: string;
+    Authorization?: string;
+  };
+  body?: string;
+};
+
+async function request(
+  url: string,
+  options: any, // Options,
+): Promise<Response | Error> {
+  // TODO: handle errors better
+  const response = await fetch(url, options);
+
+  if (!response.ok) {
+    const payload = await response.json();
+    const errors = payload.errors.map((error: string) => error).join(' ');
+    const message = `Request failed with ${response.status}, ${errors}`;
+
+    throw new Error(message);
+  }
+
+  return await response.json();
+}
+
+async function services(token?: string) {
+  // TODO: handle missing token differently
+  if (!token) {
+    return 'Missing Token';
+  }
+  const options = {
+    method: 'GET',
+    headers: {
+      Authorization: `Token token=${token}`,
+      Accept: 'application/vnd.pagerduty+json;version=2',
+      'Content-Type': 'application/json',
+    },
+  };
+  let offset = 0;
+  // TODO: Create type for this data
+  const data: any = [];
+
+  async function fetchData() {
+    const result: any = await request(
+      `${API_URL}/services?offset=${offset}`,
+      options,
+    );
+    data.push(...result.services);
+
+    // TODO: remove offset when we are done
+    if (offset < 4 && result.more) {
+      ++offset;
+      await fetchData();
+    }
+  }
+
+  await fetchData();
+  return data;
+}
 
 export interface RouterOptions {
   logger: Logger;
@@ -28,15 +96,36 @@ export interface RouterOptions {
 export async function createRouter(
   options: RouterOptions,
 ): Promise<express.Router> {
-  const { logger } = options;
+  const { logger, config } = options;
+  const token = config.getOptionalString('pagerduty.api_token') ?? undefined;
+
+  let cachedData: any = [];
+
+  let cancel = false;
+  const intervalId = setInterval(async () => {
+    if (!cancel) {
+      cancel = true;
+      const result = await services(token);
+      cachedData = result;
+      cancel = false;
+    }
+  }, 10000);
+
+  useHotCleanup(module, () => clearInterval(intervalId));
 
-  const router = Router();
   router.use(express.json());
 
+  router.get('/services', async (_, response) => {
+    logger.info('pinged');
+
+    response.send({ services: cachedData, size: cachedData.length });
+  });
+
   router.get('/health', (_, response) => {
     logger.info('PONG!');
     response.send({ status: 'ok' });
   });
+
   router.use(errorHandler());
   return router;
 }