Merge pull request #1 from Nexmo/markl-update-private-sms-tutorial

Markl update private sms tutorial

Author: lornajane

README.md

@@ -1,13 +1,13 @@
 # SMS Proxy using Node and the Nexmo SMS API
 
-This app used the Nexmo SMS API to demonstrate how to use build an SMS proxy for masked communication between users.
+This app uses the Nexmo SMS API to demonstrate how to build an SMS proxy for private communication between users. Each user sees only the other party's virtual number, not their real one.
 
 ## Prerequisites
 
 You will need:
 
 * A [free Nexmo account](https://dashboard.nexmo.com/sign-up)
-* Somewhere to host this web app, Heroku or Your Local Machine with ngrok both work well
+* Somewhere to host this web app: Heroku or your local machine with ngrok both work well
 
 ## Installation
 
@@ -25,33 +25,34 @@ Rename the config file:
 mv example.env .env
 ```
 
-Fill in the values in `.env` as appropriate.
+Fill in the values in `.env` as appropriate; this will be your API key and secret, and the Nexmo number you want to use.
 
-If preferred you can set previously provisioned numbers in the `PROVISIONED_NUMBERS` configuration value.
+If you do not have a virtual number, you can purchase one via the [dashboard](https://dashboard.nexmo.com).
+
+Configure the number's SMS webhook URL to point to your application (if you are using [ngrok](https://ngrok.com) then start your tunnel now), e.g. `https://abcd1234.ngrok.io/webhooks/inbound-sms`
 
 ### Running the App
 
 ```sh
 npm start
 ```
 
-The application should be available on <http://localhost:5000>.
+The application should be available on `http://localhost:3000`.
 
-If you have not set up predefined numbers you can access <http://localhost:5000/provision> for the application to provision numbers.
+> To change the port, try `PORT=3001 npm start` as an alternative command
 
 ### Using the App
 
-Register a conversation with the application so that mappings can be created between real user numbers and Nexmo virtual numbers. This is done by making a `POST` such as the following to <http://localhost:5000/conversation>:
+Register a conversation with the application so that mappings can be created between real user numbers and Nexmo virtual numbers. This is done by making a `POST` such as the following to `http://localhost:3000/chat`
+ and replacing `USER_A_NUMBER` and `USER_B_NUMBER` with the real numbers of the parties involved:
 
 ```
-POST /conversation HTTP/1.1
-Host: localhost:5000
+POST /chat HTTP/1.1
+Host: localhost:3000
 Cache-Control: no-cache
 Content-Type: application/x-www-form-urlencoded
 
 userANumber=USER_A_NUMBER&userBNumber=USER_B_NUMBER
 ```
 
-When you do this each of the users will receive a text. Reply to that text will allow the to communicate anonymously with each other.
-
-You can see a list of registered conversations by accessing <http://localhost:5000/conversations>.
+When you do this each of the users will receive a text. Replying to that text will allow the users to communicate anonymously with each other.

SmsProxy.js

@@ -0,0 +1,73 @@
+'use strict'
+
+const Nexmo = require('nexmo');
+
+class SmsProxy {
+
+    constructor() {
+        this.nexmo = new Nexmo({
+            apiKey: process.env.NEXMO_API_KEY,
+            apiSecret: process.env.NEXMO_API_SECRET
+        }, {
+                debug: true
+            });
+    }
+
+    createChat(userANumber, userBNumber) {
+        this.chat = {
+            userA: userANumber,
+            userB: userBNumber
+        };
+
+        this.sendSMS();
+    }
+
+    sendSMS() {
+        /*  
+            Send a message from userA to the virtual number
+        */
+        this.nexmo.message.sendSms(this.chat.userA,
+                                    process.env.VIRTUAL_NUMBER,
+                                    'Reply to this SMS to talk to UserA');
+
+        /*  
+            Send a message from userB to the virtual number
+        */
+        this.nexmo.message.sendSms(this.chat.userB,
+                                    process.env.VIRTUAL_NUMBER,
+                                    'Reply to this SMS to talk to UserB');
+    }
+
+
+    getDestinationRealNumber(from) {
+        let destinationRealNumber = null;
+
+        // Use `from` numbers to work out who is sending to whom
+        const fromUserA = (from === this.chat.userA);
+        const fromUserB = (from === this.chat.userB);
+
+        if (fromUserA || fromUserB) {
+            destinationRealNumber = fromUserA ? this.chat.userB : this.chat.userA;
+        }
+
+        return destinationRealNumber;
+    }
+
+    proxySms(from, text) {
+        // Determine which real number to send the SMS to
+        const destinationRealNumber = this.getDestinationRealNumber(from);
+
+        if (destinationRealNumber  === null) {
+            console.log(`No chat found for this number`);
+            return;
+        }
+
+        // Send the SMS from the virtual number to the real number
+        this.nexmo.message.sendSms(process.env.VIRTUAL_NUMBER,
+                                   destinationRealNumber,
+                                   text);
+    }
+
+}
+
+module.exports = SmsProxy;

config.js

@@ -1,5 +1,3 @@
 NEXMO_API_KEY=
 NEXMO_API_SECRET=
-NEXMO_DEBUG=true
-PROVISIONED_NUMBERS=[{"country":"2_CHAR_CODE","msisdn":"NUMBER"}]
-SMS_WEBHOOK_URL=
+VIRTUAL_NUMBER=