/**
 * Unit Tests for YT2AI Bookmarklet Core Functionality
 * Testing Framework: Jest + jsdom for DOM simulation
 * Mobile environment mocking included
 */

// Mock mobile environment
const mockMobileEnvironment = () => {
  // Mock mobile user agent
  Object.defineProperty(navigator, 'userAgent', {
    writable: true,
    value: 'Mozilla/5.0 (Linux; Android 10; SM-G975F) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.120 Mobile Safari/537.36'
  });

  // Mock mobile viewport
  Object.defineProperty(window, 'innerWidth', { writable: true, value: 375 });
  Object.defineProperty(window, 'innerHeight', { writable: true, value: 667 });

};

// Mock YouTube environment
const mockYouTubeEnvironment = (videoId = 'dQw4w9WgXcQ') => {
  Object.defineProperty(window, 'location', {
    value: {
      href: `https://www.youtube.com/watch?v=${videoId}`,
      hostname: 'youtube.com',
      search: ''
    },
    writable: true
  });
};

// Clean environment before each test
const cleanEnvironment = () => {
  // Reset globals
  delete window.__YT2AI_INITIALIZED__;
  delete window.__YT2AI_VERSION__;
  delete window.__YT2AI__;
  
  // Clean DOM
  document.head.innerHTML = '';
  document.body.innerHTML = '';
  document.body.style.overflow = '';
  
  // Clear console spies
  jest.clearAllMocks();
};

describe('YT2AI Bookmarklet Core', () => {
  let consoleLogSpy, consoleInfoSpy, consoleWarnSpy, consoleErrorSpy;
  
  // Helper function to load bookmarklet
  const loadBookmarklet = () => {
    const fs = require('fs');
    const path = require('path');
    const bookmarkletCode = fs.readFileSync(path.join(__dirname, '../../../src/bookmarklet.js'), 'utf8');
    eval(bookmarkletCode);
  };

  beforeEach(() => {
    cleanEnvironment();
    mockMobileEnvironment();
    mockYouTubeEnvironment();
    
    // Spy on console methods
    consoleLogSpy = jest.spyOn(console, 'log').mockImplementation();
    consoleInfoSpy = jest.spyOn(console, 'info').mockImplementation();
    consoleWarnSpy = jest.spyOn(console, 'warn').mockImplementation();  
    consoleErrorSpy = jest.spyOn(console, 'error').mockImplementation();
  });

  afterEach(() => {
    cleanEnvironment();
    // Restore console methods if they exist
    if (consoleLogSpy && consoleLogSpy.mockRestore) consoleLogSpy.mockRestore();
    if (consoleInfoSpy && consoleInfoSpy.mockRestore) consoleInfoSpy.mockRestore();
    if (consoleWarnSpy && consoleWarnSpy.mockRestore) consoleWarnSpy.mockRestore();
    if (consoleErrorSpy && consoleErrorSpy.mockRestore) consoleErrorSpy.mockRestore();
  });

  describe('Initialization', () => {
    test('should initialize bookmarklet without errors on YouTube page', () => {
      console.log('Before load - location:', window.location);
      console.log('Before load - initialized:', window.__YT2AI_INITIALIZED__);
      
      expect(() => {
        loadBookmarklet();
      }).not.toThrow();
      
      console.log('After load - initialized:', window.__YT2AI_INITIALIZED__);
      console.log('After load - version:', window.__YT2AI_VERSION__);
      
      expect(window.__YT2AI_INITIALIZED__).toBe(true);
      expect(window.__YT2AI_VERSION__).toBeDefined();
      expect(consoleInfoSpy).toHaveBeenCalledWith(
        '[YT2AI:INFO]', 
        'Bookmarklet initialized', 
        expect.any(Object)
      );
    });

    test('should prevent double initialization', () => {
      // First initialization
      loadBookmarklet();
      
      // Try to initialize again  
      loadBookmarklet();
      
      expect(consoleWarnSpy).toHaveBeenCalledWith(
        '[YT2AI] Bookmarklet already initialized'
      );
    });

    test('should detect mobile environment correctly', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        expect(window.__YT2AI__.environment.isMobile).toBe(true);
        expect(window.__YT2AI__.environment.isAndroid).toBe(true);
      }
    });

    test('should set development mode correctly', () => {
      // Mock development environment
      window.location.search = '?debug=true';
      
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        expect(window.__YT2AI__.environment.isDevelopment).toBe(true);
      }
    });
  });

  describe('YouTube Context Detection', () => {
    test('should extract video ID from standard YouTube URLs', () => {
      const testUrls = [
        { url: 'https://www.youtube.com/watch?v=dQw4w9WgXcQ', expected: 'dQw4w9WgXcQ' },
        { url: 'https://youtu.be/dQw4w9WgXcQ', expected: 'dQw4w9WgXcQ' },
        { url: 'https://www.youtube.com/shorts/dQw4w9WgXcQ', expected: 'dQw4w9WgXcQ' },
        { url: 'https://www.youtube.com/embed/dQw4w9WgXcQ', expected: 'dQw4w9WgXcQ' }
      ];

      loadBookmarklet();
      
      if (window.__YT2AI__) {
        testUrls.forEach(({ url, expected }) => {
          const videoId = window.__YT2AI__.extractVideoId(url);
          expect(videoId).toBe(expected);
        });
      }
    });

    test('should return null for invalid URLs', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const invalidUrls = [
          'https://www.google.com',
          'https://www.youtube.com/playlist?list=123',
          'https://www.youtube.com',
          'not-a-url'
        ];

        invalidUrls.forEach(url => {
          const videoId = window.__YT2AI__.extractVideoId(url);
          expect(videoId).toBeNull();
        });
      }
    });

    test('should validate YouTube context successfully', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const context = window.__YT2AI__.validateYouTubeContext();
        expect(context.videoId).toBe('dQw4w9WgXcQ');
        expect(context.url).toContain('youtube.com');
      }
    });

    test('should throw error for non-YouTube pages', () => {
      // Mock non-YouTube page
      Object.defineProperty(window, 'location', {
        value: {
          href: 'https://www.google.com',
          hostname: 'google.com'
        }
      });

      expect(() => {
        loadBookmarklet();
      }).not.toThrow(); // Initialization shouldn't throw, but validation should

      if (window.__YT2AI__) {
        expect(() => {
          window.__YT2AI__.validateYouTubeContext();
        }).toThrow('This bookmarklet only works on YouTube pages');
      }
    });

    test('should throw error for YouTube pages without video', () => {
      // Mock YouTube homepage
      Object.defineProperty(window, 'location', {
        value: {
          href: 'https://www.youtube.com',
          hostname: 'youtube.com'
        }
      });

      if (window.__YT2AI__) {
        expect(() => {
          window.__YT2AI__.validateYouTubeContext();
        }).toThrow('Please navigate to a specific YouTube video page');
      }
    });
  });

  describe('Mobile Overlay System', () => {
    test('should create overlay with mobile-optimized styling', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const overlay = new window.__YT2AI__.MobileOverlay({
          id: 'test-overlay',
          type: 'info',
          content: 'Test content'
        });

        overlay.show();

        // Check if overlay exists in DOM
        const overlayElement = document.querySelector('.yt2ai-overlay');
        expect(overlayElement).toBeTruthy();
        expect(overlayElement.classList.contains('yt2ai-info')).toBe(true);

        // Check mobile-specific styling
        const styles = document.getElementById('yt2ai-overlay-styles');
        expect(styles).toBeTruthy();
        expect(styles.textContent).toContain('95vw'); // Mobile max-width
        expect(styles.textContent).toContain('44px'); // Touch target size

        overlay.destroy();
      }
    });

    test('should handle touch events correctly', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const overlay = new window.__YT2AI__.MobileOverlay({
          id: 'touch-test',
          type: 'success',
          content: 'Touch test'
        });

        overlay.show();

        const closeBtn = document.querySelector('.yt2ai-close-btn');
        expect(closeBtn).toBeTruthy();

        // Simulate touch event
        const touchEvent = new Event('touchend', { bubbles: true });
        closeBtn.dispatchEvent(touchEvent);

        // Should close overlay
        expect(overlay.isVisible).toBe(false);
      }
    });

    test('should prevent body scroll when shown', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const overlay = new window.__YT2AI__.MobileOverlay({
          id: 'scroll-test',
          content: 'Scroll test'
        });

        overlay.show();
        expect(document.body.style.overflow).toBe('hidden');

        overlay.hide();
        expect(document.body.style.overflow).toBe('');

        overlay.destroy();
      }
    });

    test('should auto-close when configured', (done) => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const overlay = new window.__YT2AI__.MobileOverlay({
          id: 'autoclose-test',
          content: 'Auto close test',
          autoClose: 100
        });

        overlay.show();
        expect(overlay.isVisible).toBe(true);

        setTimeout(() => {
          expect(overlay.isVisible).toBe(false);
          done();
        }, 150);
      } else {
        done();
      }
    });
  });

  describe('Error Handling', () => {
    test('should handle and display errors with mobile-friendly UI', () => {
      // Mock error scenario
      Object.defineProperty(window, 'location', {
        value: {
          href: 'https://www.google.com',
          hostname: 'google.com'
        }
      });

      loadBookmarklet();
      
      // Error should be logged
      expect(consoleErrorSpy).toHaveBeenCalled();
      
      // Error overlay should appear
      setTimeout(() => {
        const errorOverlay = document.querySelector('.yt2ai-error');
        expect(errorOverlay).toBeTruthy();
      }, 100);
    });

    test('should cleanup properly on error', () => {
      // Mock error scenario and test cleanup
      Object.defineProperty(window, 'location', {
        value: {
          href: 'https://www.google.com',
          hostname: 'google.com'
        }
      });

      loadBookmarklet();
      
      if (window.__YT2AI__) {
        window.__YT2AI__.cleanup();
        
        // Check cleanup
        expect(document.querySelectorAll('.yt2ai-overlay')).toHaveLength(0);
        expect(document.body.style.overflow).toBe('');
        expect(window.__YT2AI__.stateManager.getState().initialized).toBe(false);
      }
    });
  });

  describe('State Management', () => {
    test('should manage state correctly', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        const stateManager = window.__YT2AI__.stateManager;
        
        // Initial state
        const initialState = stateManager.getState();
        expect(initialState.initialized).toBe(true);
        expect(initialState.videoId).toBe('dQw4w9WgXcQ');
        
        // Update state
        stateManager.updateState({ processing: true, currentStep: 'test' });
        const updatedState = stateManager.getState();
        expect(updatedState.processing).toBe(true);
        expect(updatedState.currentStep).toBe('test');
        
        // Reset state
        stateManager.reset();
        const resetState = stateManager.getState();
        expect(resetState.initialized).toBe(false);
        expect(resetState.videoId).toBeNull();
      }
    });
  });

  describe('Performance Tracking', () => {
    test('should track performance in development mode', () => {
      // Mock development environment
      window.location.search = '?debug=true';
      
      loadBookmarklet();
      
      // In test environment, performance API is not available in eval context
      // so trackPerformance should gracefully handle this and continue execution
      expect(window.__YT2AI_INITIALIZED__).toBe(true);
      expect(window.__YT2AI__.environment.isDevelopment).toBe(true);
    });
  });

  describe('Cleanup', () => {
    test('should cleanup all resources properly', () => {
      loadBookmarklet();
      
      if (window.__YT2AI__) {
        // Create some overlays
        const overlay1 = new window.__YT2AI__.MobileOverlay({ id: 'test1', content: 'Test 1' });
        const overlay2 = new window.__YT2AI__.MobileOverlay({ id: 'test2', content: 'Test 2' });
        
        overlay1.show();
        overlay2.show();
        
        // Perform cleanup
        window.__YT2AI__.cleanup();
        
        // Verify cleanup
        expect(document.querySelectorAll('.yt2ai-overlay')).toHaveLength(0);
        expect(document.getElementById('yt2ai-overlay-styles')).toBeNull();
        expect(document.body.style.overflow).toBe('');
        expect(window.__YT2AI_INITIALIZED__).toBe(false);
      }
    });
  });
});