Add minimal 'echo' facebook bot

README.md

@@ -5,4 +5,47 @@
 
 ## Development
 
-    $ npm i
+### 1. Install dependencies
+
+    $ npx yarn
+
+### 2. Set environment variables
+
+#### 2.1.  Generate Facebook Verify Token
+
+    $ export FB_VERIFY_TOKEN=$(tr -dc 'a-zA-Z0-9' < /dev/urandom | fold -w 32 | head -n 1)
+    $ echo Facebook Access Token: $FB_VERIFY_TOKEN
+
+#### 2.2 Set [App Secret][1]
+
+    $ export FB_APP_SECRET=''
+
+#### 2.3. Set [Facebook Access Token][2]
+
+    $ export FB_ACCESS_TOKEN=''
+
+#### 2.4 Set local dev server port
+
+    $ export PORT=3000
+
+### 3. Run the local dev server
+
+    $ npx yarn run dev
+
+### 4. Point ngrok to that local dev server
+
+    $ npx ngrok http $PORT -region eu
+
+### 5. Point the [Facebook webhook][3] to the ngrok tunnel
+
+    https://SOME_RANDOM_ID.ngrok.io/api/v1/facebook/
+
+### 6. Start chatting with your bot
+
+#### 6.1 [Monitor your requests][4]
+
+
+[1]: https://developers.facebook.com/apps/YOUR_APP_ID/settings/basic/
+[2]: https://developers.facebook.com/apps/YOUR_APP_ID/messenger/settings/
+[3]: https://developers.facebook.com/apps/YOUR_APP_ID/webhooks/
+[4]: http://localhost:4040/inspect/http

bot/facebook/index.js

@@ -0,0 +1,51 @@
+const {text, json, createError} = require('micro')
+const {get, post, withNamespace} = require('microrouter')
+
+const fbParser = require('claudia-bot-builder/lib/facebook/parse')
+const fbReply = require('claudia-bot-builder/lib/facebook/reply')
+const fbValidate = require('claudia-bot-builder/lib/facebook/validate-integrity')
+const fbTemplate = require('claudia-bot-builder/lib/facebook/format-message')
+
+const verifyToken = req => {
+  if (req.query['hub.verify_token'] === process.env.FB_VERIFY_TOKEN) {
+    return req.query['hub.challenge']
+  }
+  console.info(
+    `Your Facebook Access Token (that Facebook will echo back to you as part of callback URL verification): ${
+      process.env.FB_VERIFY_TOKEN
+    }`
+  )
+  return 'INVALID TOKEN'
+}
+
+const fbMessage = async req => {
+  req.env = {facebookAppSecret: process.env.FB_APP_SECRET}
+  req.rawBody = await text(req)
+  const data = await json(req)
+  const message = data.entry.map(
+    entry => entry.messaging.map(message => fbParser(message))[0]
+  )[0]
+
+  const isValid = fbValidate(req) && message.type === 'facebook'
+
+  return isValid ? message : false
+}
+
+const respond = async (req, res) => {
+  const message = await fbMessage(req)
+  if (message) {
+    const recipient = message.sender
+    const replyMessage = new fbTemplate.Text(
+      `You've said: "${message.text}"`
+    ).get()
+
+    await fbReply(recipient, replyMessage, process.env.FB_ACCESS_TOKEN)
+
+    res.end()
+  } else {
+    throw createError(400, 'Invalid message signature.')
+  }
+}
+
+const fbApi = withNamespace('/api/v1/facebook')
+module.exports = fbApi(get('/', verifyToken), post('/', respond))

index.js

@@ -1 +1,14 @@
-console.log('The journey of a thousand miles begins with one step. — Lao Tzu')
+const micro = require('micro')
+const {router} = require('microrouter')
+
+const fbBot = require('./bot/facebook')
+
+const bots = [fbBot, (req, res) => micro.send(res, 404, 'Not found.')]
+
+const server = micro(router(...bots))
+
+const port = process.env.PORT || 3000
+server.listen(port)
+console.info(`Listening on port ${port}`)
+
+module.exports = server

package.json

@@ -2,9 +2,19 @@
   "private": true,
   "name": "vodopija-bot",
   "version": "0.0.1",
-  "dependencies": {},
+  "scripts": {
+    "dev": "npx nodemon --inspect .",
+    "predev": "npx check-env PORT FB_APP_SECRET FB_ACCESS_TOKEN FB_VERIFY_TOKEN"
+  },
+  "dependencies": {
+    "claudia-bot-builder": "4.0.0",
+    "micro": "9.1.4",
+    "microrouter": "3.1.2"
+  },
   "devDependencies": {
+    "check-env": "1.3.0",
     "eslint-plugin-prettier": "2.6.0",
+    "ngrok": "3.0.1",
     "nodemon": "1.17.3",
     "prettier": "1.12.1",
     "xo": "0.20.3"