Adding help message support

bot/engine.js

@@ -1,11 +1,41 @@
 let { logger } = require('./logging');
-let { modules } = require('./module/index')
+let { modules } = require('./module/index');
+let trie = require('trie-prefix-tree');
+let { getShortestPrefix } = require('./utility');
+let help = require('./module/help');
+let message = require('./message');
+let utility = require('./utility');
+
+let sentinelValue = '!';
 
 class Engine {
     constructor(config, bot, modules) {
-        this.config = config
+        this.config = config;
         this.bot = bot;
         this.modules = modules;
+        this.moduleMap = new Map();
+        this.commandMap = new Map();
+        this.commandRadixTree = trie([]);
+    }
+
+    initModules() {
+        this.modules.forEach((module) => {
+            logger.info("Loading module: %s", module.name);
+            this.moduleMap.set(module.command, module);
+            this.commandMap.set(module.command, module);
+            this.commandRadixTree.addWord(module.command);
+        });
+
+        this.modules.forEach((module) => {
+            let shortCommand = getShortestPrefix(this.commandRadixTree, module.command, 3);
+            logger.info("Adding short command %s for module: %s", shortCommand, module.name);
+            this.commandMap.set(shortCommand, module);
+        });
+
+        this.helpModule = help.create(this.moduleMap)
+        this.commandMap.set('help', this.helpModule);
+
+        logger.info("Bound modules to keywords: %o", this.moduleMap);
     }
 
     init() {
@@ -13,12 +43,36 @@ class Engine {
         this.initModules();
 
         /* Bind Message Parsing */
+        let engine = this;
         let handleMessages = (event, room, toStartOfTimeline) => {
+            /* Don't process messages from self */
+            if (event.sender.userId !== this.config.userId) {
+                /* don't process messages that aren't of type m.room.message */
                 if (event.getType() !== "m.room.message") {
                     logger.debug("Recieved message of type: %s", event.getType());
-                return; // only use messages
+                    return;
+                } else {
+                    let messageBody = event.event.content.body;
+                    logger.debug("[%s] %s", room.name, messageBody);
+                    if (messageBody.indexOf(sentinelValue) === 0) {
+                        let command = messageBody.split(' ')[0].substring(1);
+                        var responseMessage = null;
+                        if (engine.commandMap.has(command)) {
+                            responseMessage = engine.commandMap.get(command).handleMessage(event, room);
                         } else {
-                logger.debug("[%s] %s", room.name, event.event.content.body);
+                            responseMessage = engine.helpModule.help();
+                        }
+
+                        logger.debug("Responding to room: %s", room.roomId);
+                        if (responseMessage instanceof Object) {
+                            engine.bot.client.sendMessage(room.roomId, responseMessage);
+                        } else if (utility.isString(responseMessage)) {
+                            engine.bot.client.sendMessage(room.roomId, message.createBasic(responseMessage));
+                        } else {
+                            logger.error("Unable to process response message: %s", responseMessage);
+                        }
+                    }
+                }
             }
         }
 
@@ -44,12 +98,6 @@ class Engine {
         return this;
     }
 
-    initModules() {
-        this.modules.forEach((module) => {
-            logger.info("Loading module: %s", module.name);
-        });
-    }
-
     run() {
         this.bot.connect();
         return this;

bot/module/abstract.js

@@ -3,6 +3,7 @@
  */
 
 let { logger } = require('../logging');
+let message = require('../message');
 
 class AbstractModule {
     name = "AbstractModule"
@@ -17,6 +18,11 @@ class AbstractModule {
 
     handleMessage(event, room) {
         logger.debug("[%s] [%s] [%s]", this.name, room.name, event.event.content.body);
+        return message.createBasic(this.name + " processed the message");
+    }
+
+    help(event, room) {
+        return message.createBasic(this.name + " HELP!");
     }
 
 }

bot/module/help.js

@@ -0,0 +1,37 @@
+/**
+ * Help module
+ */
+
+let { AbstractModule } = require('./abstract');
+let { logger } = require('../logging');
+
+class HelpModule extends AbstractModule {
+    constructor(commandMap) {
+        super(
+            "Help",
+            "Provide helpful information about other modules.",
+            "help"
+        );
+        this.commandMap = commandMap;
+    }
+
+    addCommand(command, module) {
+        logger.debug("Adding help for command %s against module %s", command, module.name);
+        this.commands.push(command);
+    }
+
+    help() {
+        let help = `!help <command>`;
+        for (let command of Array.from(this.commandMap.keys()).sort()) {
+            help += "\n!help " + command + " : " + this.commandMap.get(command).description;
+        }
+        return help;
+    }
+}
+
+function create(commandMap) {
+    return new HelpModule(commandMap);
+}
+
+exports.create = create;
+exports.module = new HelpModule();

bot/utility.js

@@ -1,6 +1,21 @@
 let fs = require('fs');
 let { logger } = require('./logging');
 
+function getShortestPrefix(radixTree, key, sliceSize) {
+    let shortKey = key.substring(0, sliceSize);
+    let keyCount = radixTree.countPrefix(shortKey);
+    if (keyCount < 1) {
+        return null;
+    }
+    if (key.length === sliceSize && radixTree.getPrefix(shortKey).includes(key)) {
+        return null;
+    }
+    if (keyCount === 1) {
+        return shortKey;
+    }
+    return getShortestPrefix(radixTree, key, sliceSize + 1);
+}
+
 function toISODateString(d) {
     function pad(n) { return n < 10 ? '0' + n : n }
     return d.getUTCFullYear() + '-'
@@ -29,6 +44,12 @@ function sleep(ms) {
     })
 }
 
+function isString(s) {
+    return typeof(s) === 'string' || s instanceof String;
+}
+
+exports.getShortestPrefix = getShortestPrefix;
 exports.toISODateString = toISODateString;
 exports.getBuildInfo = getBuildInfo;
 exports.sleep = sleep;
+exports.isString = isString;

package-lock.json

@@ -1177,6 +1177,11 @@
         }
       }
     },
+    "trie-prefix-tree": {
+      "version": "1.5.1",
+      "resolved": "https://registry.npmjs.org/trie-prefix-tree/-/trie-prefix-tree-1.5.1.tgz",
+      "integrity": "sha512-Jjvj/dA97wXnabG/NLJUgo4IQMj6vucH+Qxm7of/omfWSmZlPqdRU6Ta4GmQqCZH+n3/iYZUwfvUoEhB0Hs83Q=="
+    },
     "triple-beam": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/triple-beam/-/triple-beam-1.3.0.tgz",

package.json

@@ -9,6 +9,7 @@
   },
   "dependencies": {
     "matrix-js-sdk": "2.4.5",
+    "trie-prefix-tree": "^1.5.1",
     "winston": "^3.2.1"
   },
   "devDependencies": {