Add support for WebHooks

lib/api.js

@@ -26,7 +26,7 @@ API.prototype.request = function request(method, data) {
 const methods = ['getMe', 'sendMessage', 'forwardMessage', 'sendPhoto',
 'sendAudio', 'sendDocument', 'sendSticker', 'sendVideo',
 'sendLocation', 'sendChatAction', 'getUserProfilePhotos',
-'getUpdates'];
+'getUpdates', 'setWebhook'];
 
 methods.forEach(method => {
   API.prototype[method] = function(data) {

lib/fetch.js

@@ -5,8 +5,6 @@ export default function fetch(path, data) {
   const post = qs.stringify(data);
 
   return new Promise((resolve, reject) => {
-    let res = '';
-
     const req = https.request({
       hostname: 'api.telegram.org',
       method: data ? 'POST' : 'GET',
@@ -15,19 +13,15 @@ export default function fetch(path, data) {
         'Content-Type': 'application/x-www-form-urlencoded'
       }
     }, response => {
-      response.on('data', chunk => {
-        res += chunk;
-      });
-
-      response.on('end', () => {
+      return getBody(response).then(res => {
         try {
           let json = JSON.parse(res);
           resolve(json);
         } catch(e) {
           reject(e);
         }
-      });
-    }).on('error', reject);
+      }).catch(reject);
+    });
 
     if (post) {
       req.write(post);
@@ -37,3 +31,19 @@ export default function fetch(path, data) {
     console.error('Error sending request', err);
   });
 }
+
+export function getBody(stream) {
+  let data = '';
+
+  return new Promise((resolve, reject) => {
+    stream.on('data', chunk => {
+      data += chunk;
+    });
+
+    stream.on('end', () => {
+      resolve(data);
+    });
+
+    stream.on('error', reject);
+  });
+}

lib/index.js

@@ -1,5 +1,7 @@
 import 'babel/polyfill';
 import API from './api';
+import webhook from './webhook';
+import poll from './poll';
 import {EventEmitter} from 'events';
 
 const DEFAULTS = {
@@ -44,55 +46,38 @@ export default class Bot extends EventEmitter {
   }
 
   /**
-   * Gets information about the bot and then starts polling updates from API
+   * Gets information about the bot and then
+   * 1) starts polling updates from API
+   * 2) sets a webhook as defined by the first parameter and listens for updates
    * Emits an `update` event after polling with the response from server
    * Returns a promise which is resolved after the bot information is received
    * and set to it's `info` property i.e. bot.info
+   *
+   * @param {object} hook An object containg options passed to webhook
+   *                      properties:
+   *                       - url: HTTPS url to listen on POST requests coming
+   *                              from the Telegram API
+   *                       - port: the port to listen to, defaults to 443
+   *                       - server: An object passed to https.createServer
+   *
    * @return {promise} A promise which is resolved with the response of getMe
    */
-  start() {
-    let poll = function() {
-      return this.api.getUpdates(this.update).then(response => {
-        const again = wait(this.update.timeout * 1000).then(poll);
-
-        const result = response.result;
-        if (!result.length) {
-          return again;
-        }
-
-        if (!this.update.offset) {
-          const updateId = result[result.length - 1].update_id;
-          this.update.offset = updateId;
-        }
-        if (this.update) {
-          this.update.offset += 1;
-        }
-
-        this.emit('update', result);
-
-        result.forEach(res => {
-          let text = res.message.text;
-          if (text.startsWith('/')) {
-            // Commands are sent in /command@botusername format in groups
-            const regex = new RegExp(`@${this.info.username}$`);
-            text = text.replace(regex, '');
-          }
-
-          let ev = this._userEvents.find(({pattern}) => pattern.test(text));
-
-          if (!ev) {
-            return;
-          }
-          ev.listener(res.message);
-        });
-
-        return again;
-      });
-    }.bind(this);
-
+  start(hook) {
+    if (hook) {
+      return webhook(hook, this);
+    }
     return this.api.getMe().then(response => {
       this.info = response.result;
-      return poll();
+
+      this.on('update', this._update);
+
+      if (hook) {
+        return webhook(hook, this);
+      } else {
+        return poll(this);
+      }
+
+
     });
   }
 
@@ -142,10 +127,36 @@ export default class Bot extends EventEmitter {
   send(message) {
     return message.send(this).catch(console.error);
   }
-}
 
-const wait = (miliseconds) => {
-  return new Promise(resolve => {
-    setTimeout(resolve, miliseconds);
-  });
-};
+  /**
+   * The internal update event listener, used to parse messages and fire
+   * command/get events - YOU SHOULD NOT USE THIS
+   *
+   * @param  {object} update
+   */
+  _update(update) {
+    if (!this.update.offset) {
+      const updateId = update[update.length - 1].update_id;
+      this.update.offset = updateId;
+    }
+    if (this.update) {
+      this.update.offset += 1;
+    }
+
+    update.forEach(res => {
+      let text = res.message.text;
+      if (text.startsWith('/')) {
+        // Commands are sent in /command@thisusername format in groups
+        const regex = new RegExp(`@${this.info.username}$`);
+        text = text.replace(regex, '');
+      }
+
+      let ev = this._userEvents.find(({pattern}) => pattern.test(text));
+
+      if (!ev) {
+        return;
+      }
+      ev.listener(res.message);
+    });
+  }
+}

lib/poll.js

@@ -0,0 +1,19 @@
+export default function poll(bot) {
+  return bot.api.getUpdates(bot.update).then(response => {
+    const again = wait(bot.update.timeout * 1000, bot).then(poll);
+    if (!response.result.length) {
+      return again;
+    }
+    bot.emit('update', response.result);
+
+    return again;
+  });
+}
+
+const wait = (miliseconds, value) => {
+  return new Promise(resolve => {
+    setTimeout(() => {
+      resolve(value);
+    }, miliseconds);
+  });
+};

lib/webhook.js

@@ -0,0 +1,24 @@
+import https from 'http';
+import qs from 'qs';
+import {getBody} from './fetch';
+
+const DEFAULTS = {
+  server: {},
+  port: 443
+};
+
+export default function webhook(options = {}, bot) {
+  options = Object.assign(DEFAULTS, options);
+
+  return bot.api.setWebhook(options.url).then(() => {
+
+    https.createServer(options.server, (req, res) => {
+      return getBody(req).then(data => {
+        bot.emit('update', qs.parse(data).result);
+
+        res.end('OK');
+      });
+    }).listen(options.port);
+
+  });
+}