Implement unscrambling reaction tests

Part of #718

Author: RussellLVP

data/irc_messages.json

@@ -52,11 +52,12 @@
     "fightclub-winner": "<color:13>*** %s (Id:%d) has won the fight against %s (Id:%d) with a score of %d : %d.",
     "fightclub-draw": "<color:13>*** The fight between %s (Id:%d) and %s (Id:%d) ended in a draw.",
 
+    "reaction-calculate": "<color:6>*** First player to calculate %s wins %$!",
     "reaction-remember": "<color:6>*** Players have been asked to remember a number in order to win %$!",
     "reaction-remember-2": "<color:6>*** Players have been asked to repeat the number they were asked to remember to win %$!",
     "reaction-repeat": "<color:6>*** First player to type %s wins %$!",
-    "reaction-calculate": "<color:6>*** First player to calculate %s wins %$!",
     "reaction-result": "<color:6>*** %s (Id:%d) has won the reaction test in %d seconds!",
+    "reaction-unscramble": "<color:6>*** First player to unscramble \"%s\" wins %$!",
 
     "merchant": "<color:3>*** The merchant wants to purchase a %{1}s for %{0}$."
 }

data/messages.json

@@ -500,6 +500,7 @@
   "REACTION_TEST_ANNOUNCE_REMEMBER": "{FFFF00}You've been asked to remember the number %d...",
   "REACTION_TEST_ANNOUNCE_REMEMBER_2": "{FFFF00}The first one to repeat the number you had to remember wins %$!",
   "REACTION_TEST_ANNOUNCE_REPEAT": "{FFFF00}The first one who repeats \"%s\" wins %$!",
+  "REACTION_TEST_ANNOUNCE_UNSCRAMBLE": "{FFFF00}The first one who unscrambles \"%s\" wins %$!",
   "REACTION_TEST_ANNOUNCE_WINNER_FIRST": "{FFFF00}%s has won the reaction test in %.2f seconds. This is their first win!",
   "REACTION_TEST_ANNOUNCE_WINNER_SECOND": "{FFFF00}%s has won the reaction test in %.2f seconds. They've won once before.",
   "REACTION_TEST_ANNOUNCE_WINNER": "{FFFF00}%s has won the reaction test in %.2f seconds. They've won %d times before.",

javascript/features/reaction_tests/reaction_tests.js

@@ -6,6 +6,7 @@ import { CalculationStrategy } from 'features/reaction_tests/strategies/calculat
 import { Feature } from 'components/feature_manager/feature.js';
 import { RandomStrategy } from 'features/reaction_tests/strategies/random_strategy.js';
 import { RememberStrategy } from 'features/reaction_tests/strategies/remember_strategy.js';
+import { UnscrambleStrategy } from 'features/reaction_tests/strategies/unscramble_strategy.js';
 
 import * as achievements from 'features/collectables/achievements.js';
 
@@ -65,6 +66,7 @@ export default class ReactionTests extends Feature {
             CalculationStrategy,
             RandomStrategy,
             RememberStrategy,
+            UnscrambleStrategy,
         ];
 
         // Immediately schedule the first reaction test to start.

javascript/features/reaction_tests/strategies/random_strategy.js

@@ -48,6 +48,6 @@ export class RandomStrategy extends Strategy {
 
     // Verifies whether the |message| is, or contains, the answer to this reaction test.
     verify(message) {
-        return message.toUpperCase() === this.answer_;
+        return message.toUpperCase().startsWith(this.answer_);
     }
 }

javascript/features/reaction_tests/strategies/unscramble_strategy.js

@@ -0,0 +1,141 @@
+// Copyright 2020 Las Venturas Playground. All rights reserved.
+// Use of this source code is governed by the MIT license, a copy of which can
+// be found in the LICENSE file.
+
+import { Strategy } from 'features/reaction_tests/strategy.js';
+
+import { random } from 'base/random.js';
+
+// File that contains the word definitions for scrambled word games.
+const kWordDefinitionFile = 'data/scrambled_words.json';
+
+// Utility function to determine whether the given |charCode| should be scrambled.
+function shouldScramble(charCode) {
+    return (charCode >= 48 && charCode <= 57) || /* numbers */
+           (charCode >= 65 && charCode <= 90) || /* upper case */
+           (charCode >= 97 && charCode <= 122);  /* lower case */
+}
+
+// This strategy works by scrambling the characters in a list of predefined phrases, and requiring
+// players to guess the right word. The actual list is defined in |kWordDefinitionFile|.
+export class UnscrambleStrategy extends Strategy {
+    // How many players should be on the server in order to consider this strategy?
+    static kMinimumPlayerCount = 1;
+
+    answer_ = null;
+    scrambled_ = null;
+    settings_ = null;
+    words_ = new Set();
+
+    constructor(settings) {
+        super();
+
+        this.settings_ = settings;
+    }
+
+    // Gets the answer to the current reaction test. May be NULL.
+    get answer() { return this.answer_; }
+
+    // Gets the scrambled answer, primarily for testing purposes.
+    get scrambled() { return this.scrambled_; }
+
+    // Initializes the list of words that players should unscramble. Will be called when a test is
+    // starting, to avoid doing this too often while running tests.
+    ensureWordListInitialized() {
+        if (this.words_.size)
+            return;
+
+        const words = JSON.parse(readFile(kWordDefinitionFile));
+        for (const word of words) {
+            if (word.startsWith('__'))
+                continue;  // considered as a note/comment, ignore it
+            
+            this.words_.add(word);
+        }
+    }
+
+    // Starts a new test provided by this strategy. The question must be determined, and it should
+    // be announced to people in-game and available through Nuwani accordingly.
+    start(announceFn, nuwani, prize) {
+        this.ensureWordListInitialized();
+
+        // Pick a random phrase from the loaded word list.
+        this.answer_ = ([ ...this.words_ ][ random(this.words_.size) ]).toUpperCase();
+        this.scrambled_ = this.scramble(this.answer_);
+
+        // Announce the test to all in-game participants.
+        announceFn(Message.REACTION_TEST_ANNOUNCE_UNSCRAMBLE, this.scrambled_, prize);
+
+        // Announce the test to everyone reading along through Nuwani.
+        nuwani().echo('reaction-unscramble', this.scrambled_, prize);
+    }
+
+    // Scrambles the given |phrase| and returns the result. We decide which characters are valid to
+    // be scrambled, then scramble them, re-compose the word, and return it as a string.
+    scramble(phrase) {
+        if (phrase.trim() !== phrase)
+            console.log(`[reaction test] warning: "${phrase}" has excess spacing.`);
+        
+        const kStaticPercentage =
+            this.settings_().getValue('playground/reaction_test_unscramble_fixed');
+
+        const words = phrase.split(' ');
+        const result = [];
+
+        for (const word of words) {
+            const characters = [];
+            const fixed = new Set();
+
+            // (1) Decide which characters are supposed to be fixed.
+            for (let index = 0; index < word.length; ++index) {
+                if (random(100) < kStaticPercentage)
+                    fixed.add(index);
+            }
+
+            // (1) Collect all the characters in the |word|.
+            for (let index = 0; index < word.length; ++index) {
+                if (!shouldScramble(word.charCodeAt(index)) || fixed.has(index))
+                    continue;
+                
+                characters.push(word.charAt(index));
+            }
+
+            const shuffled = this.shuffle(characters);
+            const composed = [];
+
+            // (2) Re-compose the scrambled word.
+            for (let index = 0; index < word.length; ++index) {
+                if (shouldScramble(word.charCodeAt(index)) && !fixed.has(index))
+                    composed.push(shuffled.shift());
+                else
+                    composed.push(word.charAt(index));
+            }
+
+            result.push(composed.join(''));
+        }
+
+        // (3) Join the composed word together, then translate to upper case.
+        return result.join(' ');
+    }
+
+    // Shuffles the given |array| with the Fisher-Yates algorithm:
+    // https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
+    shuffle(array) {
+        let counter = array.length;
+
+        while (counter > 0) {
+            const index = random(counter--);
+            const temp = array[counter];
+
+            array[counter] = array[index];
+            array[index] = temp;
+        }
+
+        return array;
+    }
+
+    // Verifies whether the |message| is, or contains, the answer to this reaction test.
+    verify(message) {
+        return message.toUpperCase().startsWith(this.answer_);
+    }
+}

javascript/features/reaction_tests/strategies/unscramble_strategy.test.js

@@ -0,0 +1,79 @@
+// Copyright 2020 Las Venturas Playground. All rights reserved.
+// Use of this source code is governed by the MIT license, a copy of which can
+// be found in the LICENSE file.
+
+import { UnscrambleStrategy } from 'features/reaction_tests/strategies/unscramble_strategy.js';
+
+import { range } from 'base/range.js';
+import { symmetricDifference } from 'base/set_extensions.js';
+
+describe('UnscrambleStrategy', (it, beforeEach) => {
+    let announceFn = null;
+    let nuwani = null;
+    let settings = null;
+
+    beforeEach(() => {
+        const driver = server.featureManager.loadFeature('reaction_tests');
+
+        announceFn = driver.__proto__.announceToPlayers.bind(driver);
+        nuwani = server.featureManager.loadFeature('nuwani');
+        settings = server.featureManager.loadFeature('settings');
+    });
+
+    it('is able to scramble words while maintaining the correct answer', assert => {
+        const strategy = new UnscrambleStrategy(() => settings);
+
+        // (1) Test the shuffling function.
+        const values = range(100);
+        const shuffled = strategy.shuffle(values);
+
+        assert.equal(values.length, shuffled.length);
+        assert.equal(symmetricDifference(new Set(values), new Set(shuffled)).size, 0);
+
+        // (2) Test the scrambling function.
+        const input = 'This abcdef is xyz123 a test';
+        const scrambled = strategy.scramble(input);
+
+        assert.equal(input.length, scrambled.length);
+        assert.equal(symmetricDifference(new Set(values), new Set(shuffled)).size, 0);
+    });
+
+    it('is able to change difficulty level through static letters', assert => {
+        const strategy = new UnscrambleStrategy(() => settings);
+
+        // (1) Don't scramble the words at all.
+        settings.setValue('playground/reaction_test_unscramble_fixed', 100);
+
+        strategy.start(announceFn, () => nuwani, 1234);
+        assert.equal(strategy.answer, strategy.scrambled);
+
+        // (2) Heavily scramble the words, with on fixed letters.
+        settings.setValue('playground/reaction_test_unscramble_fixed', 0);
+
+        strategy.start(announceFn, () => nuwani, 1234);
+        assert.notEqual(strategy.answer, strategy.scrambled);
+    });
+
+    it('announces new tests to in-game players and Nuwani users', assert => {
+        const gunther = server.playerManager.getById(/* Gunther= */ 0);
+        const strategy = new UnscrambleStrategy(() => settings);
+
+        assert.equal(gunther.messages.length, 0);
+        assert.equal(nuwani.messagesForTesting.length, 0);
+
+        strategy.start(announceFn, () => nuwani, 1234);
+
+        assert.equal(gunther.messages.length, 1);
+        assert.equal(
+            gunther.messages[0],
+            Message.format(Message.REACTION_TEST_ANNOUNCE_UNSCRAMBLE, strategy.scrambled, 1234));
+
+        assert.equal(nuwani.messagesForTesting.length, 1);
+        assert.deepEqual(nuwani.messagesForTesting[0], {
+            tag: 'reaction-unscramble',
+            params: [ strategy.scrambled, 1234 ]
+        });
+
+        strategy.stop();
+    });
+});