import { describe, test, expect, beforeEach, vi } from 'vitest';
import { isTouchDevice, isOptimalTouchTarget } from './touch';

// Mock DOM APIs für Tests
const mockEventListener = vi.fn();
const mockRemoveEventListener = vi.fn();

const createMockElement = (width = 44, height = 44) => ({
	addEventListener: mockEventListener,
	removeEventListener: mockRemoveEventListener,
	getBoundingClientRect: () => ({ width, height, top: 0, left: 0, right: width, bottom: height }),
	style: {},
	appendChild: vi.fn(),
	remove: vi.fn()
});

// Mock global objects
Object.defineProperty(window, 'navigator', {
	value: {
		maxTouchPoints: 0,
		userAgent: 'Mozilla/5.0 (Test Browser)'
	},
	writable: true
});

describe('Touch Utilities', () => {
	beforeEach(() => {
		vi.clearAllMocks();
		// Reset touch support
		delete (window as any).ontouchstart;
		(window.navigator as any).maxTouchPoints = 0;
	});

	describe('isTouchDevice', () => {
		test('should detect touch support via ontouchstart', () => {
			(window as any).ontouchstart = true;
			expect(isTouchDevice()).toBe(true);
		});

		test('should detect touch support via maxTouchPoints', () => {
			(window.navigator as any).maxTouchPoints = 1;
			expect(isTouchDevice()).toBe(true);
		});

		test('should return false for non-touch devices', () => {
			expect(isTouchDevice()).toBe(false);
		});
	});

	describe('isOptimalTouchTarget', () => {
		test('should return true for 44x44 elements', () => {
			const element = createMockElement(44, 44);
			expect(isOptimalTouchTarget(element as any)).toBe(true);
		});

		test('should return true for larger elements', () => {
			const element = createMockElement(50, 60);
			expect(isOptimalTouchTarget(element as any)).toBe(true);
		});

		test('should return false for small width', () => {
			const element = createMockElement(30, 44);
			expect(isOptimalTouchTarget(element as any)).toBe(false);
		});

		test('should return false for small height', () => {
			const element = createMockElement(44, 30);
			expect(isOptimalTouchTarget(element as any)).toBe(false);
		});

		test('should return false for small elements', () => {
			const element = createMockElement(20, 20);
			expect(isOptimalTouchTarget(element as any)).toBe(false);
		});
	});
});

describe('Touch Actions (Integration)', () => {
	let mockElement: any;

	beforeEach(() => {
		mockElement = createMockElement();
		vi.clearAllMocks();
	});

	describe('Event Registration', () => {
		test('should register touch and pointer events', () => {
			// Diese Tests würden die tatsächlichen Touch-Actions testen
			// Für jetzt testen wir nur die Utility-Funktionen
			expect(mockEventListener).not.toHaveBeenCalled();
		});
	});

	describe('Gesture Recognition', () => {
		test('should calculate touch distances correctly', () => {
			const touch1 = { clientX: 0, clientY: 0 };
			const touch2 = { clientX: 100, clientY: 100 };
			
			// Math.sqrt(100^2 + 100^2) = Math.sqrt(20000) ≈ 141.42
			const expectedDistance = Math.sqrt(20000);
			const actualDistance = Math.sqrt(
				Math.pow(touch2.clientX - touch1.clientX, 2) + 
				Math.pow(touch2.clientY - touch1.clientY, 2)
			);
			
			expect(actualDistance).toBeCloseTo(expectedDistance, 2);
		});

		test('should detect horizontal swipes', () => {
			const startTouch = { clientX: 0, clientY: 100 };
			const endTouch = { clientX: 100, clientY: 100 };
			
			const deltaX = endTouch.clientX - startTouch.clientX;
			const deltaY = endTouch.clientY - startTouch.clientY;
			const absDeltaX = Math.abs(deltaX);
			const absDeltaY = Math.abs(deltaY);
			
			// Horizontal swipe: |deltaX| > |deltaY|
			expect(absDeltaX).toBeGreaterThan(absDeltaY);
			expect(deltaX).toBeGreaterThan(0); // Right swipe
		});

		test('should detect vertical swipes', () => {
			const startTouch = { clientX: 100, clientY: 0 };
			const endTouch = { clientX: 100, clientY: 100 };
			
			const deltaX = endTouch.clientX - startTouch.clientX;
			const deltaY = endTouch.clientY - startTouch.clientY;
			const absDeltaX = Math.abs(deltaX);
			const absDeltaY = Math.abs(deltaY);
			
			// Vertical swipe: |deltaY| > |deltaX|
			expect(absDeltaY).toBeGreaterThan(absDeltaX);
			expect(deltaY).toBeGreaterThan(0); // Down swipe
		});
	});

	describe('Touch Target Validation', () => {
		test('should validate minimum touch target sizes', () => {
			const sizes = [
				{ width: 44, height: 44, expected: true },
				{ width: 48, height: 48, expected: true },
				{ width: 40, height: 40, expected: false },
				{ width: 44, height: 40, expected: false },
				{ width: 40, height: 44, expected: false }
			];

			sizes.forEach(({ width, height, expected }) => {
				const element = createMockElement(width, height);
				expect(isOptimalTouchTarget(element as any)).toBe(expected);
			});
		});
	});

	describe('Performance Considerations', () => {
		test('should handle rapid touch events', () => {
			// Simuliere viele schnelle Touch-Events
			const events = Array.from({ length: 100 }, (_, i) => ({
				clientX: i,
				clientY: i,
				timestamp: Date.now() + i
			}));

			// In einer echten Implementation würden wir Throttling/Debouncing testen
			expect(events).toHaveLength(100);
			
			// Teste dass Events innerhalb vernünftiger Zeit verarbeitet werden können
			const startTime = Date.now();
			events.forEach(event => {
				// Simuliere Event-Verarbeitung
				const deltaX = event.clientX;
				const deltaY = event.clientY;
				Math.sqrt(deltaX * deltaX + deltaY * deltaY);
			});
			const endTime = Date.now();
			
			expect(endTime - startTime).toBeLessThan(100); // Sollte sehr schnell sein
		});
	});

	describe('Accessibility Considerations', () => {
		test('should maintain focus accessibility', () => {
			// Touch-Actions sollten Keyboard-Navigation nicht beeinträchtigen
			const element = createMockElement();
			
			// Simuliere dass Element fokussierbar bleibt
			element.tabIndex = 0;
			element.setAttribute = vi.fn();
			
			expect(element.tabIndex).toBe(0);
		});

		test('should work with screen readers', () => {
			// Touch-Targets sollten Screen-Reader-kompatibel bleiben
			const element = createMockElement();
			element.getAttribute = vi.fn().mockReturnValue('button');
			element.textContent = 'Touch Button';
			
			expect(element.getAttribute('role')).toBe('button');
			expect(element.textContent).toBe('Touch Button');
		});
	});
});