Add dinosaur wet metrics

src/dinosaurwet/dinosaurwet.controller.ts

@@ -2,6 +2,9 @@ import { Controller, Get, Res } from '@nestjs/common';
 import { Response } from 'express';
 import { identity, prop } from 'ramda';
 import * as xml from 'xml';
+import { InjectMetric } from '@willsoto/nestjs-prometheus';
+import { Gauge } from 'prom-client';
+import { ApiTags } from '@nestjs/swagger';
 
 const episodeFiles: [number, string][] = [
   [27544345, '01-Into-the-Big-Wet.mp3'],
@@ -60,6 +63,34 @@ const buildFeeds = (
   episodes: Episode[],
   pubDateFn: (index: number) => Date = () => startDate,
 ) => {
+  const episodeItems = episodes
+    .filter((episode: Episode, index: number) => pubDateFn(index) <= new Date())
+    .map(({ title, url, length, fakeReleaseDate }, index) => ({
+      item: [
+        { title },
+        { guid: url },
+        { pubDate: pubDateFn(index).toUTCString() },
+        {
+          'itunes:image': {
+            _attr: {
+              href: dinosaurImage,
+            },
+          },
+        },
+        { 'itunes:episode': index + 1 },
+        {
+          enclosure: [
+            {
+              _attr: {
+                url,
+                type: 'audio/mpeg',
+                length,
+              },
+            },
+          ],
+        },
+      ],
+    }));
   const feedObject = {
     rss: [
       {
@@ -100,48 +131,24 @@ const buildFeeds = (
               'A recreation of Dinosaur Wet as an RSS feed for listeners-with-licenses enjoyment.',
           },
           { language: 'en-US' },
-          ...episodes
-            .filter(
-              (episode: Episode, index: number) =>
-                pubDateFn(index) <= new Date(),
-            )
-            .map(({ title, url, length, fakeReleaseDate }, index) => ({
-              item: [
-                { title },
-                { guid: url },
-                { pubDate: pubDateFn(index).toUTCString() },
-                {
-                  'itunes:image': {
-                    _attr: {
-                      href: dinosaurImage,
-                    },
-                  },
-                },
-                { 'itunes:episode': index + 1 },
-                {
-                  enclosure: [
-                    {
-                      _attr: {
-                        url,
-                        type: 'audio/mpeg',
-                        length,
-                      },
-                    },
-                  ],
-                },
-              ],
-            })),
+          ...episodeItems,
         ],
       },
     ],
   };
 
   const feed = '<?xml version="1.0" encoding="UTF-8"?>' + xml(feedObject);
-  return feed;
+  return { feed, episodeItems };
 };
 
+@ApiTags('dinosaurwet')
 @Controller('dinosaurwet')
 export class DinosaurwetController {
+  constructor(
+    @InjectMetric('weekly_count') public weeklyCount: Gauge<string>,
+    @InjectMetric('daily_count') public dailyCount: Gauge<string>,
+  ) {}
+
   @Get('')
   getAllAtOnce(@Res() response: Response) {
     response.header('Content-Type', 'application/xml');
@@ -158,7 +165,8 @@ export class DinosaurwetController {
       (index: number) =>
         new Date(new Date(startDate).setDate(startDate.getDate() + index)),
     );
-    return response.send(feed);
+    this.dailyCount.set(feed.episodeItems.length);
+    return response.send(feed.feed);
   }
 
   @Get('weekly')
@@ -170,6 +178,7 @@ export class DinosaurwetController {
       (index: number) =>
         new Date(new Date(startDate).setDate(startDate.getDate() + index * 7)),
     );
-    return response.send(feed);
+    this.weeklyCount.set(feed.episodeItems.length);
+    return response.send(feed.feed);
   }
 }