From b0c301bc1b43a9ac98687973ba397bd574f3043b Mon Sep 17 00:00:00 2001
From: Michael Barrett <michaelbarrett@hey.com>
Date: Sat, 12 Sep 2020 13:52:42 -0400
Subject: [PATCH] Add client level command listeners

---
 example/example.js        |  4 ++++
 lib/client.js             | 37 +++++++++++++++++++++++++++++++++++--
 lib/clientManager.js      | 11 +++++++++++
 test/clientManagerTest.js | 11 +++++++++++
 test/clientTest.js        |  2 +-
 5 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/example/example.js b/example/example.js
index 71db221..c71fc99 100644
--- a/example/example.js
+++ b/example/example.js
@@ -21,6 +21,10 @@ gameManager.on('clientAdded', (client) => {
 });
 
 const server = new GMServer(function (client) {
+  client.addCommandListener('register', () => {
+    console.log('Client is registering.');
+  });
+
   gameManager.addClient(client);
 });
 
diff --git a/lib/client.js b/lib/client.js
index f771dc8..15f9407 100644
--- a/lib/client.js
+++ b/lib/client.js
@@ -3,12 +3,13 @@
 const _ = require('lodash');
 const TERMINATING_CHARACTER = '\0';
 const DEBUG_MODE = process.env.GM_SERVER_DEBUG === 'true';
-const TERM_STR = '^X|X^';
+const TERM_STR = '\n\t\n';
 
 class Client {
   constructor (socket) {
     this.socket = socket;
     this.dataHandlers = [];
+    this.commandHandlers = {};
     this.clientId = _.uniqueId();
     this.created = Date.now();
     this.data = {};
@@ -22,13 +23,20 @@ class Client {
         console.info(this.clientId, ' received: ', JSON.stringify(dataAsObject));
       }
 
+      // Low level handlers
       this.dataHandlers.forEach(handler => {
         handler(dataAsObject);
       });
+
+      // Client level command handlers
+      if (this.commandHandlers[dataAsObject.command]) {
+        this.commandHandlers[dataAsObject.command].forEach(handler => {
+          handler(dataAsObject);
+        });
+      }
     });
 
     socket.on('error', error => {
-      console.error('oops');
       console.error(error);
     });
   }
@@ -105,6 +113,31 @@ class Client {
     this.dataHandlers.push(handler);
   }
 
+  /**
+   * Registers a callback function for when a given command is sent in by this client
+   * @param {string} command   The command to listen for
+   * @param {function} handler A callback to run when the command is received
+   */
+  addCommandListener (command, handler) {
+    // If there is a command listener for this command already, push.
+    if (this.commandHandlers[command]) {
+      this.commandHandlers[command].push(handler);
+    } else {
+      this.commandHandlers[command] = [handler];
+    }
+  }
+
+  /**
+   * Removes a registered callback function for when a given command is sent in by this client
+   * @param {string} command   The command to listen for
+   * @param {function} handler The function to remove
+   */
+  removeCommandListener (command, handler) {
+    if (this.commandHandlers[command]) {
+      this.commandHandlers[command] = this.commandHandlers[command].filter(fn => fn !== handler);
+    }
+  }
+
   /**
    * Sets tick mode on or off.
    * @param {boolean} onOff
diff --git a/lib/clientManager.js b/lib/clientManager.js
index e73697b..802c701 100644
--- a/lib/clientManager.js
+++ b/lib/clientManager.js
@@ -140,6 +140,17 @@ class ClientManager {
     }
   }
 
+  /**
+   * Removes a registered callback function for when a given command is sent in by a client
+   * @param {string} command   The command to listen for
+   * @param {function} handler The function to remove
+   */
+  removeCommandListener (command, handler) {
+    if (this.commandHandlers[command]) {
+      this.commandHandlers[command] = this.commandHandlers[command].filter(fn => fn !== handler);
+    }
+  }
+
   /**
    * Registers an event handler for ClientManager events
    * @param  {string} eventName The event to listen for
diff --git a/test/clientManagerTest.js b/test/clientManagerTest.js
index e581ce2..e3940b0 100644
--- a/test/clientManagerTest.js
+++ b/test/clientManagerTest.js
@@ -99,6 +99,17 @@ describe('Client Manager', function () {
     });
   });
 
+  describe('.removeCommandListener()', function () {
+    it('removes registered commands', function () {
+      const handlerStub = sinon.stub();
+      clientManager.addCommandListener('test', handlerStub);
+      clientManager.removeCommandListener('test', handlerStub);
+      clientManager.handleIncomingCommand(getFakeClient(), { command: 'test' });
+      clientManager.handleIncomingCommand(getFakeClient(), { command: 'doNotRun' });
+      assert(!handlerStub.called, 'The registered command handler was called');
+    });
+  });
+
   describe('.broadcast()', function () {
     it('can broadcast to all clients', function () {
       const fakeSocket = getFakeClient();
diff --git a/test/clientTest.js b/test/clientTest.js
index 7f663e8..f7d1656 100644
--- a/test/clientTest.js
+++ b/test/clientTest.js
@@ -7,7 +7,7 @@ const Client = require('../lib/client.js');
 const _ = require('lodash');
 let client;
 let fakeSocket;
-const TERM_STR = '^X|X^';
+const TERM_STR = '\n\t\n';
 
 function getFakeNetSocket () {
   return {