handle serving stale data snapshots

.env.sample

@@ -19,6 +19,7 @@ API_LEGACY_BATTLENET_KEY=''
 API_LEGACY_BATTLENET_SECRET=''
 API_BATTLENET_KEY=''
 API_BATTLENET_SECRET=''
-API_BATTLENET_APIS_DISABLED='false'
+API_BATTLENET_APIS_DISABLED_JANUARY_2020='false'
 API_TWITCH_EXTENSION_SHARED_SECRET=''
 API_TWITCH_EXTENSION_CLIENT_ID=''
+API_SNAPSHOT_DATA_DIRECTORY='../sc2pte-data-snapshot'

src/config/battlenet.js

@@ -14,5 +14,6 @@ bnetConfig.apiKey = env.API_BATTLENET_KEY;
 /** Battle.net API secret */
 bnetConfig.apiSecret = env.API_BATTLENET_SECRET;
 bnetConfig.apiDisabledJanuary2020 = env.API_BATTLENET_APIS_DISABLED_JANUARY_2020 === 'true';
+bnetConfig.snapshotDataDirectory = env.API_SNAPSHOT_DATA_DIRECTORY;
 
 module.exports = bnetConfig;

src/index.js

@@ -19,14 +19,15 @@ const appConfig = require('./config/app');
 const dbConfig = require('./config/database');
 const twitchConfig = require('./config/twitch');
 const redisConfig = require('./config/redis');
+const bnetConfig = require('./config/battlenet');
 
 const getViewerRoutes = require('./routes/v1.1/viewer/get');
 const saveConfigRoutes = require('./routes/v1.1/config/save');
 const getConfigRoutes = require('./routes/v1.1/config/get');
 
 const db = require('./plugins/db');
-
 const sc2pte = require('./plugins/sc2pte');
+const snapshot = require('./plugins/snapshot');
 
 const { env } = process;
 
@@ -102,6 +103,12 @@ if (env.API_HOST_PROTOCOL === 'https') {
   server.register(tlsKeygen);
 }
 
+/* Data snapshots for dark times in January 2020 when Battle.net API is down */
+
+server.register(snapshot, {
+  dataDir: bnetConfig.snapshotDataDirectory,
+});
+
 /* Routes */
 
 server.register(getViewerRoutes);

src/plugins/db.js

@@ -32,6 +32,7 @@ module.exports = fp(async (server, opts, next) => {
       keepAlive: true,
       useFindAndModify: false,
       useCreateIndex: true,
+      useUnifiedTopology: true,
     },
   );
 

src/plugins/snapshot.js

@@ -0,0 +1,30 @@
+const fp = require('fastify-plugin');
+const fs = require('fs');
+
+function snapshot(fastify, options, next) { // eslint-disable-line consistent-return
+  const { dataDir } = options;
+
+  function getViewerData(channelId) {
+    try {
+      const content = fs.readFileSync(`${dataDir}/${channelId}.json`, 'utf8');
+      const contentObject = JSON.parse(content);
+      if (contentObject.player && contentObject.ladders) {
+        return content;
+      }
+      return fs.readFileSync(`${dataDir}/blank.json`, 'utf8');
+    } catch (error) {
+      return fs.readFileSync(`${dataDir}/blank.json`, 'utf8');
+    }
+  }
+
+  fastify.decorate('snapshot', {
+    getViewerData,
+  });
+
+  next();
+}
+
+module.exports = fp(snapshot, {
+  fastify: '>=2.0.0',
+  name: 'snapshot',
+});

src/routes/v1.1/viewer/get/index.js

@@ -3,7 +3,7 @@ const fp = require('fastify-plugin');
 const schema = require('./schema');
 
 const redisConfig = require('../../../../config/redis');
-// const bnetConfig = require('../../../../config/battlenet');
+const bnetConfig = require('../../../../config/battlenet');
 
 module.exports = fp(async (server, opts, next) => {
   server.route({
@@ -36,6 +36,13 @@ module.exports = fp(async (server, opts, next) => {
           return reply.code(200).send(cachedReply.item);
         }
         server.log.info('generating and caching response...');
+
+        if (bnetConfig.apiDisabledJanuary2020) {
+          const responseObject = server.snapshot.getViewerData(channelId);
+          await server.cache.set(redisKey, responseObject, redisConfig.replyCachePeriod);
+          return reply.code(200).send(responseObject);
+        }
+
         const channelConfigObject = await server.db.models.ChannelConfig.findOne({ channelId });
 
         if (channelConfigObject && channelConfigObject._doc) { // eslint-disable-line