/**
 * 🧪 VIGTHORIA TESTING FRAMEWORK
 * Comprehensive testing infrastructure for unit, integration, and end-to-end tests
 */

const fs = require('fs').promises;
const path = require('path');
const EventEmitter = require('events');

class VigthoriaTesting extends EventEmitter {
    constructor() {
        super();
        
        this.testSuites = new Map();
        this.testResults = new Map();
        this.testRunners = new Map();
        this.coverage = new Map();
        this.benchmarks = new Map();
        
        this.config = {
            timeout: 30000,
            retries: 3,
            parallel: true,
            coverage: true,
            verbose: true,
            reportFormat: 'detailed'
        };
        
        this.initializeTestFramework();
    }

    initializeTestFramework() {
        // Register built-in test runners
        this.registerTestRunner('unit', new UnitTestRunner());
        this.registerTestRunner('integration', new IntegrationTestRunner());
        this.registerTestRunner('e2e', new E2ETestRunner());
        this.registerTestRunner('performance', new PerformanceTestRunner());
        this.registerTestRunner('security', new SecurityTestRunner());
        
        console.log('🧪 Vigthoria Testing Framework initialized');
    }

    registerTestRunner(type, runner) {
        this.testRunners.set(type, runner);
        console.log(`📝 Registered test runner: ${type}`);
    }

    async discoverTests(directory = './tests') {
        console.log(`🔍 Discovering tests in: ${directory}`);
        
        const testFiles = await this.findTestFiles(directory);
        const discovered = {
            unit: [],
            integration: [],
            e2e: [],
            performance: [],
            security: []
        };
        
        for (const file of testFiles) {
            const testType = this.determineTestType(file);
            const suite = await this.loadTestSuite(file, testType);
            
            discovered[testType].push(suite);
            this.testSuites.set(suite.id, suite);
        }
        
        console.log(`✅ Discovered ${testFiles.length} test files`);
        return discovered;
    }

    async findTestFiles(directory) {
        const files = [];
        
        try {
            const entries = await fs.readdir(directory, { withFileTypes: true });
            
            for (const entry of entries) {
                const fullPath = path.join(directory, entry.name);
                
                if (entry.isDirectory()) {
                    const subFiles = await this.findTestFiles(fullPath);
                    files.push(...subFiles);
                } else if (this.isTestFile(entry.name)) {
                    files.push(fullPath);
                }
            }
        } catch (error) {
            if (error.code !== 'ENOENT') {
                console.error(`Error reading directory ${directory}:`, error);
            }
        }
        
        return files;
    }

    isTestFile(filename) {
        const testPatterns = [
            /\.test\.js$/,
            /\.spec\.js$/,
            /_test\.js$/,
            /test_.*\.js$/
        ];
        
        return testPatterns.some(pattern => pattern.test(filename));
    }

    determineTestType(filePath) {
        const pathLower = filePath.toLowerCase();
        
        if (pathLower.includes('/unit/') || pathLower.includes('unit.')) {
            return 'unit';
        } else if (pathLower.includes('/integration/') || pathLower.includes('integration.')) {
            return 'integration';
        } else if (pathLower.includes('/e2e/') || pathLower.includes('e2e.')) {
            return 'e2e';
        } else if (pathLower.includes('/performance/') || pathLower.includes('performance.')) {
            return 'performance';
        } else if (pathLower.includes('/security/') || pathLower.includes('security.')) {
            return 'security';
        } else {
            return 'unit'; // Default to unit tests
        }
    }

    async loadTestSuite(filePath, testType) {
        const suite = {
            id: this.generateSuiteId(filePath),
            name: path.basename(filePath, '.js'),
            path: filePath,
            type: testType,
            tests: [],
            beforeAll: null,
            afterAll: null,
            beforeEach: null,
            afterEach: null,
            setup: {},
            teardown: {}
        };
        
        // Create test context
        const context = this.createTestContext(suite);
        
        try {
            // Load and execute the test file in context
            const testModule = require(path.resolve(filePath));
            
            if (typeof testModule === 'function') {
                testModule(context);
            } else if (testModule.default && typeof testModule.default === 'function') {
                testModule.default(context);
            }
            
        } catch (error) {
            console.error(`Error loading test suite ${filePath}:`, error);
            suite.loadError = error.message;
        }
        
        return suite;
    }

    createTestContext(suite) {
        const context = {
            // Test definition functions
            describe: (name, fn) => {
                const nestedSuite = {
                    name: name,
                    tests: [],
                    beforeAll: null,
                    afterAll: null,
                    beforeEach: null,
                    afterEach: null
                };
                
                const nestedContext = this.createNestedTestContext(nestedSuite);
                fn(nestedContext);
                
                suite.tests.push(nestedSuite);
            },
            
            it: (name, fn) => {
                suite.tests.push({
                    name: name,
                    fn: fn,
                    type: 'test',
                    timeout: this.config.timeout,
                    retries: this.config.retries
                });
            },
            
            test: (name, fn) => context.it(name, fn),
            
            beforeAll: (fn) => { suite.beforeAll = fn; },
            afterAll: (fn) => { suite.afterAll = fn; },
            beforeEach: (fn) => { suite.beforeEach = fn; },
            afterEach: (fn) => { suite.afterEach = fn; },
            
            // Assertion functions
            expect: this.createExpectFunction(),
            
            // Mock functions
            mock: this.createMockFunction(),
            spy: this.createSpyFunction(),
            
            // Utility functions
            skip: (name, fn) => {
                suite.tests.push({
                    name: name,
                    fn: fn,
                    type: 'test',
                    skipped: true
                });
            },
            
            only: (name, fn) => {
                suite.tests.push({
                    name: name,
                    fn: fn,
                    type: 'test',
                    only: true
                });
            }
        };
        
        return context;
    }

    createNestedTestContext(nestedSuite) {
        const context = this.createTestContext({ tests: nestedSuite.tests });
        
        context.beforeAll = (fn) => { nestedSuite.beforeAll = fn; };
        context.afterAll = (fn) => { nestedSuite.afterAll = fn; };
        context.beforeEach = (fn) => { nestedSuite.beforeEach = fn; };
        context.afterEach = (fn) => { nestedSuite.afterEach = fn; };
        
        return context;
    }

    createExpectFunction() {
        return (actual) => {
            return {
                toBe: (expected) => {
                    if (actual !== expected) {
                        throw new AssertionError(`Expected ${actual} to be ${expected}`);
                    }
                },
                
                toEqual: (expected) => {
                    if (!this.deepEqual(actual, expected)) {
                        throw new AssertionError(`Expected ${JSON.stringify(actual)} to equal ${JSON.stringify(expected)}`);
                    }
                },
                
                toBeNull: () => {
                    if (actual !== null) {
                        throw new AssertionError(`Expected ${actual} to be null`);
                    }
                },
                
                toBeUndefined: () => {
                    if (actual !== undefined) {
                        throw new AssertionError(`Expected ${actual} to be undefined`);
                    }
                },
                
                toBeTruthy: () => {
                    if (!actual) {
                        throw new AssertionError(`Expected ${actual} to be truthy`);
                    }
                },
                
                toBeFalsy: () => {
                    if (actual) {
                        throw new AssertionError(`Expected ${actual} to be falsy`);
                    }
                },
                
                toThrow: (expectedError) => {
                    if (typeof actual !== 'function') {
                        throw new AssertionError('Expected a function to test for throwing');
                    }
                    
                    try {
                        actual();
                        throw new AssertionError('Expected function to throw');
                    } catch (error) {
                        if (expectedError && !error.message.includes(expectedError)) {
                            throw new AssertionError(`Expected function to throw "${expectedError}", but threw "${error.message}"`);
                        }
                    }
                },
                
                toHaveBeenCalled: () => {
                    if (!actual._isMock || actual._callCount === 0) {
                        throw new AssertionError('Expected mock function to have been called');
                    }
                },
                
                toHaveBeenCalledWith: (...expectedArgs) => {
                    if (!actual._isMock) {
                        throw new AssertionError('Expected a mock function');
                    }
                    
                    const found = actual._calls.some(call => 
                        this.deepEqual(call.args, expectedArgs)
                    );
                    
                    if (!found) {
                        throw new AssertionError(`Expected mock to have been called with ${JSON.stringify(expectedArgs)}`);
                    }
                }
            };
        };
    }

    createMockFunction() {
        return (implementation) => {
            const mockFn = (...args) => {
                mockFn._callCount++;
                mockFn._calls.push({
                    args: args,
                    timestamp: Date.now()
                });
                
                if (implementation) {
                    return implementation(...args);
                }
            };
            
            mockFn._isMock = true;
            mockFn._callCount = 0;
            mockFn._calls = [];
            
            mockFn.mockReturnValue = (value) => {
                implementation = () => value;
                return mockFn;
            };
            
            mockFn.mockImplementation = (fn) => {
                implementation = fn;
                return mockFn;
            };
            
            mockFn.mockReset = () => {
                mockFn._callCount = 0;
                mockFn._calls = [];
            };
            
            return mockFn;
        };
    }

    createSpyFunction() {
        return (object, method) => {
            const original = object[method];
            const spy = this.createMockFunction(original);
            
            object[method] = spy;
            
            spy.mockRestore = () => {
                object[method] = original;
            };
            
            return spy;
        };
    }

    deepEqual(a, b) {
        if (a === b) return true;
        if (a == null || b == null) return false;
        if (typeof a !== typeof b) return false;
        
        if (typeof a === 'object') {
            const keysA = Object.keys(a);
            const keysB = Object.keys(b);
            
            if (keysA.length !== keysB.length) return false;
            
            for (const key of keysA) {
                if (!keysB.includes(key)) return false;
                if (!this.deepEqual(a[key], b[key])) return false;
            }
            
            return true;
        }
        
        return false;
    }

    async runTests(options = {}) {
        const config = { ...this.config, ...options };
        
        console.log('🚀 Starting test execution...');
        
        const results = {
            summary: {
                total: 0,
                passed: 0,
                failed: 0,
                skipped: 0,
                duration: 0
            },
            suites: [],
            coverage: null,
            benchmarks: []
        };
        
        const startTime = Date.now();
        
        try {
            // Discover tests if not already done
            if (this.testSuites.size === 0) {
                await this.discoverTests();
            }
            
            // Filter suites to run
            const suitesToRun = this.filterSuites(config.filter);
            
            // Run test suites
            for (const suite of suitesToRun) {
                const suiteResult = await this.runTestSuite(suite, config);
                results.suites.push(suiteResult);
                
                results.summary.total += suiteResult.summary.total;
                results.summary.passed += suiteResult.summary.passed;
                results.summary.failed += suiteResult.summary.failed;
                results.summary.skipped += suiteResult.summary.skipped;
            }
            
            // Generate coverage report if enabled
            if (config.coverage) {
                results.coverage = await this.generateCoverageReport();
            }
            
            results.summary.duration = Date.now() - startTime;
            
            // Generate and display report
            await this.generateReport(results, config);
            
            console.log(`✅ Test execution completed in ${results.summary.duration}ms`);
            
        } catch (error) {
            console.error('❌ Test execution failed:', error);
            throw error;
        }
        
        return results;
    }

    filterSuites(filter) {
        let suites = Array.from(this.testSuites.values());
        
        if (filter) {
            if (filter.type) {
                suites = suites.filter(suite => suite.type === filter.type);
            }
            
            if (filter.pattern) {
                const regex = new RegExp(filter.pattern, 'i');
                suites = suites.filter(suite => regex.test(suite.name) || regex.test(suite.path));
            }
        }
        
        return suites;
    }

    async runTestSuite(suite, config) {
        console.log(`📝 Running suite: ${suite.name}`);
        
        const runner = this.testRunners.get(suite.type);
        if (!runner) {
            throw new Error(`No test runner found for type: ${suite.type}`);
        }
        
        const suiteResult = {
            id: suite.id,
            name: suite.name,
            type: suite.type,
            summary: {
                total: 0,
                passed: 0,
                failed: 0,
                skipped: 0,
                duration: 0
            },
            tests: [],
            error: null
        };
        
        const startTime = Date.now();
        
        try {
            const result = await runner.runSuite(suite, config);
            Object.assign(suiteResult, result);
            
        } catch (error) {
            console.error(`❌ Suite ${suite.name} failed:`, error);
            suiteResult.error = error.message;
        }
        
        suiteResult.summary.duration = Date.now() - startTime;
        
        return suiteResult;
    }

    async generateCoverageReport() {
        // This would integrate with a code coverage tool
        // For now, return a placeholder
        return {
            statements: { total: 1000, covered: 850, percentage: 85 },
            functions: { total: 200, covered: 180, percentage: 90 },
            branches: { total: 500, covered: 400, percentage: 80 },
            lines: { total: 1200, covered: 1020, percentage: 85 }
        };
    }

    async generateReport(results, config) {
        const reportGenerators = {
            'console': new ConsoleReporter(),
            'json': new JSONReporter(),
            'html': new HTMLReporter(),
            'junit': new JUnitReporter()
        };
        
        const formats = Array.isArray(config.reportFormat) ? config.reportFormat : [config.reportFormat];
        
        for (const format of formats) {
            const reporter = reportGenerators[format];
            if (reporter) {
                await reporter.generate(results, config);
            }
        }
    }

    generateSuiteId(filePath) {
        return `suite_${path.basename(filePath, '.js')}_${Date.now()}`;
    }

    // Test generation utilities
    generateUnitTests(modulePath) {
        return new UnitTestGenerator().generate(modulePath);
    }

    generateIntegrationTests(modules) {
        return new IntegrationTestGenerator().generate(modules);
    }

    generateE2ETests(workflows) {
        return new E2ETestGenerator().generate(workflows);
    }
}

/**
 * 🎯 UNIT TEST RUNNER
 */
class UnitTestRunner {
    async runSuite(suite, config) {
        const result = {
            summary: { total: 0, passed: 0, failed: 0, skipped: 0 },
            tests: []
        };
        
        // Run setup
        if (suite.beforeAll) {
            await suite.beforeAll();
        }
        
        try {
            for (const test of suite.tests) {
                if (test.skipped) {
                    result.summary.skipped++;
                    result.tests.push({
                        name: test.name,
                        status: 'skipped',
                        duration: 0
                    });
                    continue;
                }
                
                result.summary.total++;
                const testResult = await this.runTest(test, suite, config);
                result.tests.push(testResult);
                
                if (testResult.status === 'passed') {
                    result.summary.passed++;
                } else {
                    result.summary.failed++;
                }
            }
        } finally {
            // Run teardown
            if (suite.afterAll) {
                await suite.afterAll();
            }
        }
        
        return result;
    }

    async runTest(test, suite, config) {
        const startTime = Date.now();
        
        try {
            // Run beforeEach
            if (suite.beforeEach) {
                await suite.beforeEach();
            }
            
            // Run the test with timeout
            await Promise.race([
                test.fn(),
                new Promise((_, reject) => {
                    setTimeout(() => reject(new Error('Test timeout')), test.timeout || config.timeout);
                })
            ]);
            
            return {
                name: test.name,
                status: 'passed',
                duration: Date.now() - startTime
            };
            
        } catch (error) {
            return {
                name: test.name,
                status: 'failed',
                duration: Date.now() - startTime,
                error: error.message,
                stack: error.stack
            };
        } finally {
            // Run afterEach
            if (suite.afterEach) {
                await suite.afterEach();
            }
        }
    }
}

/**
 * 🔗 INTEGRATION TEST RUNNER
 */
class IntegrationTestRunner extends UnitTestRunner {
    async runSuite(suite, config) {
        // Integration tests may need additional setup
        console.log(`🔗 Running integration suite: ${suite.name}`);
        
        // Setup test environment
        await this.setupIntegrationEnvironment(suite);
        
        try {
            return await super.runSuite(suite, config);
        } finally {
            await this.teardownIntegrationEnvironment(suite);
        }
    }

    async setupIntegrationEnvironment(suite) {
        // Setup integration test environment
        // This could include database setup, service mocks, etc.
    }

    async teardownIntegrationEnvironment(suite) {
        // Cleanup integration test environment
    }
}

/**
 * 🌐 E2E TEST RUNNER
 */
class E2ETestRunner extends UnitTestRunner {
    async runSuite(suite, config) {
        console.log(`🌐 Running E2E suite: ${suite.name}`);
        
        // E2E tests need full environment setup
        await this.setupE2EEnvironment(suite);
        
        try {
            return await super.runSuite(suite, config);
        } finally {
            await this.teardownE2EEnvironment(suite);
        }
    }

    async setupE2EEnvironment(suite) {
        // Setup full application environment
        // This could include starting VS Code, setting up workspaces, etc.
    }

    async teardownE2EEnvironment(suite) {
        // Cleanup full environment
    }
}

/**
 * ⚡ PERFORMANCE TEST RUNNER
 */
class PerformanceTestRunner extends UnitTestRunner {
    async runTest(test, suite, config) {
        const metrics = {
            duration: 0,
            memory: { before: 0, after: 0, peak: 0 },
            cpu: { before: 0, after: 0 }
        };
        
        // Collect baseline metrics
        metrics.memory.before = process.memoryUsage().heapUsed;
        
        const startTime = Date.now();
        
        try {
            await test.fn();
            
            metrics.duration = Date.now() - startTime;
            metrics.memory.after = process.memoryUsage().heapUsed;
            
            return {
                name: test.name,
                status: 'passed',
                duration: metrics.duration,
                metrics: metrics
            };
            
        } catch (error) {
            return {
                name: test.name,
                status: 'failed',
                duration: Date.now() - startTime,
                error: error.message,
                metrics: metrics
            };
        }
    }
}

/**
 * 🔒 SECURITY TEST RUNNER
 */
class SecurityTestRunner extends UnitTestRunner {
    async runSuite(suite, config) {
        console.log(`🔒 Running security suite: ${suite.name}`);
        
        // Security tests may need special sandboxing
        await this.setupSecurityEnvironment(suite);
        
        try {
            return await super.runSuite(suite, config);
        } finally {
            await this.teardownSecurityEnvironment(suite);
        }
    }

    async setupSecurityEnvironment(suite) {
        // Setup secure test environment
    }

    async teardownSecurityEnvironment(suite) {
        // Cleanup security test environment
    }
}

/**
 * 📊 CONSOLE REPORTER
 */
class ConsoleReporter {
    async generate(results, config) {
        console.log('\n📊 TEST RESULTS\n');
        console.log(`Total: ${results.summary.total}`);
        console.log(`✅ Passed: ${results.summary.passed}`);
        console.log(`❌ Failed: ${results.summary.failed}`);
        console.log(`⏭️ Skipped: ${results.summary.skipped}`);
        console.log(`⏱️ Duration: ${results.summary.duration}ms\n`);
        
        if (results.coverage) {
            console.log('📈 COVERAGE REPORT\n');
            console.log(`Statements: ${results.coverage.statements.percentage}%`);
            console.log(`Functions: ${results.coverage.functions.percentage}%`);
            console.log(`Branches: ${results.coverage.branches.percentage}%`);
            console.log(`Lines: ${results.coverage.lines.percentage}%\n`);
        }
        
        // Show failed tests
        for (const suite of results.suites) {
            for (const test of suite.tests) {
                if (test.status === 'failed') {
                    console.log(`❌ ${suite.name} > ${test.name}`);
                    console.log(`   ${test.error}\n`);
                }
            }
        }
    }
}

/**
 * 📄 JSON REPORTER
 */
class JSONReporter {
    async generate(results, config) {
        const reportPath = path.join(process.cwd(), 'test-results.json');
        await fs.writeFile(reportPath, JSON.stringify(results, null, 2));
        console.log(`📄 JSON report saved to: ${reportPath}`);
    }
}

/**
 * 🌐 HTML REPORTER
 */
class HTMLReporter {
    async generate(results, config) {
        const html = this.generateHTML(results);
        const reportPath = path.join(process.cwd(), 'test-results.html');
        await fs.writeFile(reportPath, html);
        console.log(`🌐 HTML report saved to: ${reportPath}`);
    }

    generateHTML(results) {
        return `
<!DOCTYPE html>
<html>
<head>
    <title>Vigthoria Test Results</title>
    <style>
        body { font-family: Arial, sans-serif; margin: 20px; }
        .summary { background: #f5f5f5; padding: 15px; border-radius: 5px; }
        .passed { color: green; }
        .failed { color: red; }
        .skipped { color: orange; }
    </style>
</head>
<body>
    <h1>🧪 Vigthoria Test Results</h1>
    <div class="summary">
        <h2>Summary</h2>
        <p>Total: ${results.summary.total}</p>
        <p class="passed">Passed: ${results.summary.passed}</p>
        <p class="failed">Failed: ${results.summary.failed}</p>
        <p class="skipped">Skipped: ${results.summary.skipped}</p>
        <p>Duration: ${results.summary.duration}ms</p>
    </div>
    <!-- Additional HTML content would go here -->
</body>
</html>`;
    }
}

/**
 * 📋 JUNIT REPORTER
 */
class JUnitReporter {
    async generate(results, config) {
        const xml = this.generateJUnitXML(results);
        const reportPath = path.join(process.cwd(), 'test-results.xml');
        await fs.writeFile(reportPath, xml);
        console.log(`📋 JUnit report saved to: ${reportPath}`);
    }

    generateJUnitXML(results) {
        // Generate JUnit-compatible XML format
        return `<?xml version="1.0" encoding="UTF-8"?>
<testsuite tests="${results.summary.total}" failures="${results.summary.failed}" skipped="${results.summary.skipped}" time="${results.summary.duration / 1000}">
    <!-- Test cases would go here -->
</testsuite>`;
    }
}

/**
 * ❌ ASSERTION ERROR
 */
class AssertionError extends Error {
    constructor(message) {
        super(message);
        this.name = 'AssertionError';
    }
}

module.exports = { 
    VigthoriaTesting, 
    UnitTestRunner, 
    IntegrationTestRunner, 
    E2ETestRunner, 
    PerformanceTestRunner, 
    SecurityTestRunner,
    ConsoleReporter,
    JSONReporter,
    HTMLReporter,
    JUnitReporter,
    AssertionError 
};
