/**
 * @fileoverview Cross-Platform Compatibility Tests
 * @author GrabZilla Development Team
 * @version 2.1.0
 * @since 2024-01-01
 */

import { describe, it, expect, beforeEach, vi } from 'vitest';
import os from 'os';
import path from 'path';
import fs from 'fs';

/**
 * CROSS-PLATFORM COMPATIBILITY TESTS
 * 
 * These tests verify that the application works correctly across:
 * - macOS (darwin)
 * - Windows (win32)
 * - Linux (linux)
 * 
 * Testing areas:
 * - Binary path resolution
 * - File system operations
 * - Path handling
 * - Process spawning
 * - Platform-specific features
 */

describe('Cross-Platform Compatibility', () => {
    let currentPlatform;
    let mockPlatformInfo;

    beforeEach(() => {
        currentPlatform = process.platform;
        mockPlatformInfo = {
            platform: currentPlatform,
            arch: process.arch,
            homedir: os.homedir(),
            tmpdir: os.tmpdir(),
            pathSep: path.sep
        };
    });

    describe('Platform Detection and Binary Paths', () => {
        it('should detect current platform correctly', () => {
            const supportedPlatforms = ['darwin', 'win32', 'linux'];
            expect(supportedPlatforms).toContain(currentPlatform);
        });

        it('should resolve correct binary paths for each platform', () => {
            const getBinaryPath = (binaryName, platform = currentPlatform) => {
                const extension = platform === 'win32' ? '.exe' : '';
                return path.join('binaries', `${binaryName}${extension}`);
            };

            // Test for current platform
            const ytDlpPath = getBinaryPath('yt-dlp');
            const ffmpegPath = getBinaryPath('ffmpeg');

            if (currentPlatform === 'win32') {
                expect(ytDlpPath).toBe('binaries\\yt-dlp.exe');
                expect(ffmpegPath).toBe('binaries\\ffmpeg.exe');
            } else {
                expect(ytDlpPath).toBe('binaries/yt-dlp');
                expect(ffmpegPath).toBe('binaries/ffmpeg');
            }

            // Test for all platforms
            expect(getBinaryPath('yt-dlp', 'win32')).toMatch(/\.exe$/);
            expect(getBinaryPath('yt-dlp', 'darwin')).not.toMatch(/\.exe$/);
            expect(getBinaryPath('yt-dlp', 'linux')).not.toMatch(/\.exe$/);
        });

        it('should handle platform-specific path separators', () => {
            const createPath = (...segments) => path.join(...segments);

            const testPath = createPath('downloads', 'videos', 'test.mp4');
            
            if (currentPlatform === 'win32') {
                expect(testPath).toMatch(/\\/);
            } else {
                expect(testPath).toMatch(/\//);
            }
        });

        it('should resolve home directory correctly on all platforms', () => {
            const homeDir = os.homedir();
            
            expect(homeDir).toBeTruthy();
            expect(path.isAbsolute(homeDir)).toBe(true);
            
            // Platform-specific home directory patterns
            if (currentPlatform === 'win32') {
                expect(homeDir).toMatch(/^[A-Z]:\\/);
            } else {
                expect(homeDir).toMatch(/^\/.*\/[^/]+$/);
            }
        });
    });

    describe('File System Operations', () => {
        it('should handle file paths with different separators', () => {
            // Use path.join for cross-platform compatibility
            const testPaths = [
                path.join('downloads', 'video.mp4'),
                path.join('downloads', 'subfolder', 'video.mp4')
            ];

            testPaths.forEach(testPath => {
                const normalized = path.normalize(testPath);
                expect(normalized).toBeTruthy();

                const parsed = path.parse(normalized);
                expect(parsed.name).toBe('video');
                expect(parsed.ext).toBe('.mp4');

                // The base name should be consistent regardless of path separators
                expect(parsed.base).toBe('video.mp4');

                // Verify the path contains the expected directory
                expect(normalized).toMatch(/downloads/);
            });
        });

        it('should create directories with correct permissions', () => {
            const testDir = path.join(os.tmpdir(), 'grabzilla-test-' + Date.now());
            
            try {
                fs.mkdirSync(testDir, { recursive: true });
                expect(fs.existsSync(testDir)).toBe(true);
                
                const stats = fs.statSync(testDir);
                expect(stats.isDirectory()).toBe(true);
                
                // Check permissions (Unix-like systems)
                if (currentPlatform !== 'win32') {
                    expect(stats.mode & 0o777).toBeGreaterThan(0);
                }
            } finally {
                // Cleanup
                if (fs.existsSync(testDir)) {
                    fs.rmSync(testDir, { recursive: true, force: true });
                }
            }
        });

        it('should handle long file paths appropriately', () => {
            const longFileName = 'a'.repeat(200) + '.mp4';
            const longPath = path.join(os.tmpdir(), longFileName);
            
            // Windows has path length limitations
            if (currentPlatform === 'win32') {
                expect(longPath.length).toBeLessThan(260); // Windows MAX_PATH
            }
            
            // Test path parsing with long names
            const parsed = path.parse(longPath);
            expect(parsed.ext).toBe('.mp4');
        });

        it('should handle special characters in file names', () => {
            const specialChars = {
                'win32': ['<', '>', ':', '"', '|', '?', '*'],
                'darwin': [':'],
                'linux': []
            };

            const invalidChars = specialChars[currentPlatform] || [];
            
            const testFileName = 'test_video_with_special_chars.mp4';
            
            // Verify our test filename doesn't contain invalid characters
            invalidChars.forEach(char => {
                expect(testFileName).not.toContain(char);
            });
            
            // Test sanitization function
            const sanitizeFileName = (name) => {
                let sanitized = name;
                invalidChars.forEach(char => {
                    sanitized = sanitized.replace(new RegExp(`\\${char}`, 'g'), '_');
                });
                return sanitized;
            };

            const dirtyName = 'test<video>file.mp4';
            const cleanName = sanitizeFileName(dirtyName);
            
            if (currentPlatform === 'win32') {
                expect(cleanName).toBe('test_video_file.mp4');
            } else {
                expect(cleanName).toBe(dirtyName); // No changes needed on Unix-like systems
            }
        });
    });

    describe('Process Management', () => {
        it('should handle process spawning correctly on all platforms', () => {
            const getShellCommand = () => {
                switch (currentPlatform) {
                    case 'win32':
                        return { cmd: 'cmd', args: ['/c', 'echo', 'test'] };
                    default:
                        return { cmd: 'echo', args: ['test'] };
                }
            };

            const { cmd, args } = getShellCommand();
            expect(cmd).toBeTruthy();
            expect(Array.isArray(args)).toBe(true);
        });

        it('should handle process termination signals correctly', () => {
            const getTerminationSignal = () => {
                return currentPlatform === 'win32' ? 'SIGTERM' : 'SIGTERM';
            };

            const signal = getTerminationSignal();
            expect(['SIGTERM', 'SIGKILL', 'SIGINT']).toContain(signal);
        });

        it('should handle environment variables correctly', () => {
            const pathVar = process.env.PATH || process.env.Path;
            expect(pathVar).toBeTruthy();
            
            const pathSeparator = currentPlatform === 'win32' ? ';' : ':';
            const paths = pathVar.split(pathSeparator);
            expect(paths.length).toBeGreaterThan(0);
        });
    });

    describe('Platform-Specific Features', () => {
        it('should handle macOS-specific features', () => {
            if (currentPlatform === 'darwin') {
                // Test macOS-specific paths
                const applicationsPath = '/Applications';
                expect(fs.existsSync(applicationsPath)).toBe(true);
                
                // Test bundle handling
                const bundleExtensions = ['.app', '.bundle'];
                bundleExtensions.forEach(ext => {
                    expect(ext.startsWith('.')).toBe(true);
                });
            } else {
                // Skip macOS-specific tests on other platforms
                expect(currentPlatform).not.toBe('darwin');
            }
        });

        it('should handle Windows-specific features', () => {
            if (currentPlatform === 'win32') {
                // Test Windows-specific paths
                const systemRoot = process.env.SystemRoot;
                expect(systemRoot).toBeTruthy();
                expect(systemRoot).toMatch(/^[A-Z]:\\/);
                
                // Test executable extensions
                const executableExtensions = ['.exe', '.bat', '.cmd'];
                executableExtensions.forEach(ext => {
                    expect(ext.startsWith('.')).toBe(true);
                });
            } else {
                // Skip Windows-specific tests on other platforms
                expect(currentPlatform).not.toBe('win32');
            }
        });

        it('should handle Linux-specific features', () => {
            if (currentPlatform === 'linux') {
                // Test Linux-specific paths
                const homeDir = os.homedir();
                expect(homeDir).toMatch(/^\/home\/|^\/root$/);
                
                // Test executable permissions
                const executableMode = 0o755;
                expect(executableMode & 0o111).toBeGreaterThan(0); // Execute permissions
            } else {
                // Skip Linux-specific tests on other platforms
                expect(currentPlatform).not.toBe('linux');
            }
        });
    });

    describe('File Dialog Integration', () => {
        it('should provide platform-appropriate file dialog options', () => {
            const getFileDialogOptions = (type) => {
                const baseOptions = {
                    title: 'Select File',
                    buttonLabel: 'Select'
                };

                switch (type) {
                    case 'save':
                        return {
                            ...baseOptions,
                            defaultPath: path.join(os.homedir(), 'Downloads'),
                            filters: [
                                { name: 'Video Files', extensions: ['mp4', 'mkv', 'avi'] },
                                { name: 'All Files', extensions: ['*'] }
                            ]
                        };
                    case 'cookie':
                        return {
                            ...baseOptions,
                            filters: [
                                { name: 'Text Files', extensions: ['txt'] },
                                { name: 'All Files', extensions: ['*'] }
                            ]
                        };
                    default:
                        return baseOptions;
                }
            };

            const saveOptions = getFileDialogOptions('save');
            const cookieOptions = getFileDialogOptions('cookie');

            expect(saveOptions.defaultPath).toContain(os.homedir());
            expect(saveOptions.filters).toHaveLength(2);
            expect(cookieOptions.filters).toHaveLength(2);
        });

        it('should handle default download directories per platform', () => {
            const getDefaultDownloadPath = () => {
                const homeDir = os.homedir();
                
                switch (currentPlatform) {
                    case 'win32':
                        return path.join(homeDir, 'Downloads');
                    case 'darwin':
                        return path.join(homeDir, 'Downloads');
                    case 'linux':
                        return path.join(homeDir, 'Downloads');
                    default:
                        return homeDir;
                }
            };

            const downloadPath = getDefaultDownloadPath();
            expect(path.isAbsolute(downloadPath)).toBe(true);
            expect(downloadPath).toContain(os.homedir());
        });
    });

    describe('Notification System', () => {
        it('should provide platform-appropriate notification options', () => {
            const getNotificationOptions = (title, body) => {
                const baseOptions = {
                    title,
                    body,
                    silent: false
                };

                switch (currentPlatform) {
                    case 'win32':
                        return {
                            ...baseOptions,
                            toastXml: null // Windows-specific toast XML
                        };
                    case 'darwin':
                        return {
                            ...baseOptions,
                            sound: 'default' // macOS notification sound
                        };
                    case 'linux':
                        return {
                            ...baseOptions,
                            urgency: 'normal' // Linux notification urgency
                        };
                    default:
                        return baseOptions;
                }
            };

            const options = getNotificationOptions('Test', 'Test notification');
            expect(options.title).toBe('Test');
            expect(options.body).toBe('Test notification');
            
            // Platform-specific properties
            if (currentPlatform === 'win32') {
                expect(options).toHaveProperty('toastXml');
            } else if (currentPlatform === 'darwin') {
                expect(options).toHaveProperty('sound');
            } else if (currentPlatform === 'linux') {
                expect(options).toHaveProperty('urgency');
            }
        });
    });

    describe('Performance Characteristics', () => {
        it('should account for platform-specific performance differences', () => {
            const performanceMetrics = {
                startupTime: 0,
                memoryUsage: process.memoryUsage(),
                cpuUsage: process.cpuUsage()
            };

            // Simulate startup time measurement
            const startTime = Date.now();
            // Simulate some work
            for (let i = 0; i < 1000000; i++) {
                Math.random();
            }
            performanceMetrics.startupTime = Date.now() - startTime;

            expect(performanceMetrics.startupTime).toBeGreaterThan(0);
            expect(performanceMetrics.memoryUsage.heapUsed).toBeGreaterThan(0);
            expect(performanceMetrics.cpuUsage.user).toBeGreaterThanOrEqual(0);
        });

        it('should handle concurrent operations efficiently per platform', () => {
            const maxConcurrency = currentPlatform === 'win32' ? 2 : 3; // Windows might be more conservative
            
            expect(maxConcurrency).toBeGreaterThan(0);
            expect(maxConcurrency).toBeLessThanOrEqual(4);
        });
    });

    describe('Error Handling and Recovery', () => {
        it('should provide platform-specific error messages', () => {
            const getErrorMessage = (errorType) => {
                const messages = {
                    'file_not_found': {
                        'win32': 'The system cannot find the file specified.',
                        'darwin': 'No such file or directory',
                        'linux': 'No such file or directory'
                    },
                    'permission_denied': {
                        'win32': 'Access is denied.',
                        'darwin': 'Permission denied',
                        'linux': 'Permission denied'
                    }
                };

                return messages[errorType]?.[currentPlatform] || 'Unknown error';
            };

            const fileNotFoundMsg = getErrorMessage('file_not_found');
            const permissionDeniedMsg = getErrorMessage('permission_denied');

            expect(fileNotFoundMsg).toBeTruthy();
            expect(permissionDeniedMsg).toBeTruthy();
            
            if (currentPlatform === 'win32') {
                expect(fileNotFoundMsg).toContain('system cannot find');
                expect(permissionDeniedMsg).toContain('Access is denied');
            } else {
                expect(fileNotFoundMsg).toContain('No such file');
                expect(permissionDeniedMsg).toContain('Permission denied');
            }
        });

        it('should handle platform-specific recovery strategies', () => {
            const getRecoveryStrategy = (errorType) => {
                switch (errorType) {
                    case 'binary_not_found':
                        return currentPlatform === 'win32' 
                            ? 'Check PATH environment variable and .exe extension'
                            : 'Check PATH and executable permissions';
                    case 'network_error':
                        return 'Check internet connection and firewall settings';
                    default:
                        return 'Try restarting the application';
                }
            };

            const binaryStrategy = getRecoveryStrategy('binary_not_found');
            const networkStrategy = getRecoveryStrategy('network_error');

            expect(binaryStrategy).toBeTruthy();
            expect(networkStrategy).toBeTruthy();
            
            if (currentPlatform === 'win32') {
                expect(binaryStrategy).toContain('.exe');
            } else {
                expect(binaryStrategy).toContain('permissions');
            }
        });
    });
});