feat: Implement intro screen with retro 80s aesthetic and unit tests

src/css/screens.css

@@ -60,3 +60,58 @@
   font-size: 14px;
   color: var(--text-color);
 }
+/* Intro Screen Styles */
+.intro-screen {
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    justify-content: center;
+    height: 100vh;
+    background-color: #0a0a1a;
+    color: #00ff00;
+    font-family: 'Courier New', monospace;
+    text-align: center;
+}
+
+.title {
+    font-size: 48px;
+    font-weight: bold;
+    margin-bottom: 20px;
+    text-shadow: 0 0 10px #00ff00;
+    letter-spacing: 4px;
+}
+
+.credits {
+    font-size: 16px;
+    margin-bottom: 30px;
+    color: #a0a0a0;
+}
+
+.instructions {
+    font-size: 14px;
+    margin-bottom: 30px;
+    color: #00ff00;
+    line-height: 1.5;
+}
+
+.options {
+    margin-top: 20px;
+}
+
+.option {
+    padding: 10px 20px;
+    margin: 5px 0;
+    font-size: 18px;
+    cursor: pointer;
+    transition: all 0.2s;
+    border: 2px solid transparent;
+}
+
+.option.selected {
+    border-color: #00ff00;
+    background-color: rgba(0, 255, 0, 0.1);
+}
+
+.option:hover {
+    background-color: rgba(0, 255, 0, 0.2);
+}

src/index.html

@@ -27,3 +27,15 @@
     <script src="js/screens/loading.js"></script>
 </body>
 </html>
+<div id="screen" class="screen">
+    <!-- Screen content will be dynamically loaded -->
+</div>
+<div id="screen" class="screen">
+    <!-- Screen content will be dynamically loaded -->
+</div>
+<div id="screen" class="screen">
+    <!-- Screen content will be dynamically loaded -->
+</div>
+<div id="screen" class="screen">
+    <!-- Screen content will be dynamically loaded -->
+</div>

src/js/screens/intro.js

@@ -0,0 +1,98 @@
+class IntroScreen {
+    constructor() {
+        this.title = 'WINGS88';
+        this.credits = 'A RetroWeb Games Production';
+        this.instructions = 'Use arrow keys to fly\nPress SPACE to start';
+        this.options = ['Start Game', 'Instructions', 'Quit'];
+        this.selectedOption = 0;
+        this.audioContext = null;
+        this.musicTrack = null;
+    }
+
+    init() {
+        this.setupAudio();
+        this.render();
+        this.setupEventListeners();
+    }
+
+    setupAudio() {
+        try {
+            this.audioContext = new (window.AudioContext || window.webkitAudioContext)();
+            this.loadMusic();
+        } catch (e) {
+            console.log('Audio initialization failed:', e);
+        }
+    }
+
+    loadMusic() {
+        // Placeholder for retro MIDI music
+        console.log('Loading retro music...');
+    }
+
+    render() {
+        const screen = document.getElementById('screen');
+        screen.innerHTML = `
+            <div class="intro-screen">
+                <div class="title">${this.title}</div>
+                <div class="credits">${this.credits}</div>
+                <div class="instructions">${this.instructions}</div>
+                <div class="options">
+                    ${this.options.map((option, index) => `
+                        <div class="option ${index === this.selectedOption ? 'selected' : ''}">
+                            ${option}
+                        </div>
+                    `).join('')}
+                </div>
+            </div>
+        `;
+    }
+
+    setupEventListeners() {
+        document.addEventListener('keydown', (e) => this.handleKeyDown(e));
+    }
+
+    handleKeyDown(e) {
+        switch(e.key) {
+            case 'ArrowUp':
+                this.moveSelection(-1);
+                break;
+            case 'ArrowDown':
+                this.moveSelection(1);
+                break;
+            case 'Enter':
+                this.selectOption();
+                break;
+            case 'Escape':
+                this.selectOption();
+                break;
+        }
+    }
+
+    moveSelection(direction) {
+        this.selectedOption = (this.selectedOption + direction + this.options.length) % this.options.length;
+        this.render();
+    }
+
+    selectOption() {
+        switch(this.selectedOption) {
+            case 0:
+                console.log('Starting game...');
+                break;
+            case 1:
+                console.log('Showing instructions...');
+                break;
+            case 2:
+                console.log('Quitting game...');
+                break;
+        }
+    }
+
+    cleanup() {
+        document.removeEventListener('keydown', this.handleKeyDown);
+        if (this.audioContext) {
+            this.audioContext.close();
+        }
+    }
+}
+
+module.exports = IntroScreen;

tests/unit/intro.test.js

@@ -0,0 +1,85 @@
+const IntroScreen = require('../../src/js/screens/intro');
+
+describe('IntroScreen', () => {
+    let introScreen;
+
+    beforeEach(() => {
+        introScreen = new IntroScreen();
+    });
+
+    describe('constructor', () => {
+        it('should initialize with correct default values', () => {
+            expect(introScreen.title).toBe('WINGS88');
+            expect(introScreen.credits).toBe('A RetroWeb Games Production');
+            expect(introScreen.instructions).toBe('Use arrow keys to fly\nPress SPACE to start');
+            expect(introScreen.options).toEqual(['Start Game', 'Instructions', 'Quit']);
+            expect(introScreen.selectedOption).toBe(0);
+            expect(introScreen.audioContext).toBeNull();
+            expect(introScreen.musicTrack).toBeNull();
+        });
+    });
+
+    describe('moveSelection', () => {
+        it('should move selection up', () => {
+            introScreen.selectedOption = 1;
+            // Mock render to prevent DOM access
+            introScreen.render = jest.fn();
+            introScreen.moveSelection(-1);
+            expect(introScreen.selectedOption).toBe(0);
+            expect(introScreen.render).toHaveBeenCalled();
+        });
+
+        it('should move selection down', () => {
+            introScreen.selectedOption = 0;
+            // Mock render to prevent DOM access
+            introScreen.render = jest.fn();
+            introScreen.moveSelection(1);
+            expect(introScreen.selectedOption).toBe(1);
+            expect(introScreen.render).toHaveBeenCalled();
+        });
+
+        it('should wrap around from last to first', () => {
+            introScreen.selectedOption = 2;
+            // Mock render to prevent DOM access
+            introScreen.render = jest.fn();
+            introScreen.moveSelection(1);
+            expect(introScreen.selectedOption).toBe(0);
+            expect(introScreen.render).toHaveBeenCalled();
+        });
+
+        it('should wrap around from first to last', () => {
+            introScreen.selectedOption = 0;
+            // Mock render to prevent DOM access
+            introScreen.render = jest.fn();
+            introScreen.moveSelection(-1);
+            expect(introScreen.selectedOption).toBe(2);
+            expect(introScreen.render).toHaveBeenCalled();
+        });
+    });
+
+    describe('selectOption', () => {
+        it('should handle Start Game selection', () => {
+            introScreen.selectedOption = 0;
+            const logSpy = jest.spyOn(console, 'log');
+            introScreen.selectOption();
+            expect(logSpy).toHaveBeenCalledWith('Starting game...');
+            logSpy.mockRestore();
+        });
+
+        it('should handle Instructions selection', () => {
+            introScreen.selectedOption = 1;
+            const logSpy = jest.spyOn(console, 'log');
+            introScreen.selectOption();
+            expect(logSpy).toHaveBeenCalledWith('Showing instructions...');
+            logSpy.mockRestore();
+        });
+
+        it('should handle Quit selection', () => {
+            introScreen.selectedOption = 2;
+            const logSpy = jest.spyOn(console, 'log');
+            introScreen.selectOption();
+            expect(logSpy).toHaveBeenCalledWith('Quitting game...');
+            logSpy.mockRestore();
+        });
+    });
+});