Generalized random responder (replacing dag bot)

config/slack-random-response.json

@@ -0,0 +1,8 @@
+[
+  {
+    "botName": "Dag Bot",
+    "defaultEmoji": ":dog:",
+    "trigger": "d(o|a)g facts?",
+    "responseUrl": "https://raw.githubusercontent.com/18F/18f-bot-facts/master/dags.json"
+  }
+]

scripts/random-responses.js

@@ -0,0 +1,95 @@
+const fs = require('fs');
+const configs = JSON.parse(
+  fs.readFileSync('config/slack-random-response.json')
+);
+
+const cachedRequests = {};
+
+const getResponses = async (robot, config) => {
+  if (config.responseList) {
+    return config.responseList;
+  }
+
+  if (config.responseUrl) {
+    if (cachedRequests[config.responseUrl]) {
+      const cached = cachedRequests[config.responseUrl];
+      if (Date.now() < cached.expiry) {
+        return cached.value;
+      }
+    }
+
+    return new Promise(resolve => {
+      robot
+        .http(config.responseUrl)
+        .header('User-Agent', '18F-bot')
+        .get()((err, res, body) => {
+        cachedRequests[config.responseUrl] = {
+          expiry: Date.now() + 60000, // five minutes
+          value: JSON.parse(body)
+        };
+        resolve(JSON.parse(body));
+      });
+    });
+  }
+};
+
+const responseFrom = (
+  robot,
+  { botName = null, defaultEmoji = null, ...config } = {}
+) => async res => {
+  const message = {};
+  if (defaultEmoji) {
+    message.icon_emoji = defaultEmoji;
+  }
+  if (botName) {
+    message.username = botName;
+  }
+
+  const responses = await getResponses(robot, config);
+  const response = res.random(responses);
+
+  if (typeof response === 'object') {
+    message.text = response.text;
+    if (response.name) {
+      message.username = response.name + (botName ? ` (${botName})` : '');
+    }
+    if (response.emoji) {
+      message.icon_emoji = response.emoji;
+    }
+  } else {
+    message.text = response;
+    const match = response.match(/^(:[^:]+:)(.*)$/);
+    if (match) {
+      message.icon_emoji = match[1];
+      message.text = match[2].trim();
+    }
+  }
+
+  if (message.icon_emoji || message.username) {
+    message.as_user = false;
+  }
+
+  res.send(message);
+};
+
+const attachTrigger = (robot, trigger, config) => {
+  if (Array.isArray(trigger)) {
+    trigger.forEach(t =>
+      robot.hear(new RegExp(t, 'i'), responseFrom(robot, config))
+    );
+  } else {
+    robot.hear(new RegExp(trigger, 'i'), responseFrom(robot, config));
+  }
+};
+
+module.exports = robot => {
+  if (Array.isArray(configs)) {
+    configs.forEach(async config => {
+      attachTrigger(robot, config.trigger, config);
+    });
+  }
+};
+
+module.exports.attachTrigger = attachTrigger;
+module.exports.getResponses = getResponses;
+module.exports.responseFrom = responseFrom;