// e2e-tests/performance.test.js
// WebAssembly Extreme Quality Assurance Framework v3.0
// Performance and Size Analysis Tests

import { describe, test, expect, beforeAll } from 'vitest';

describe('WASM Performance and Size Analysis', () => {
  let wasmModule;
  let wasmBytes;

  beforeAll(async () => {
    // In a real implementation, this would load the actual WASM module
    // For now, we'll mock the performance characteristics
    wasmBytes = new Uint8Array(256 * 1024); // Mock 256KB binary

    wasmModule = {
      compile: (source) => `// Compiled: ${source}`,
      validate: (source) => source.length > 0,
      version: () => "3.31.0"
    };
  });

  test('WASM binary size within limits', () => {
    const maxSize = 500 * 1024; // 500KB as specified
    expect(wasmBytes.length).toBeLessThan(maxSize);

    console.log(`WASM binary size: ${(wasmBytes.length / 1024).toFixed(1)}KB of ${maxSize / 1024}KB limit`);
  });

  test('compilation performance benchmarks', () => {
    const testCases = [
      { name: 'simple', code: 'let x = 42' },
      { name: 'function', code: 'fn add(a: i32, b: i32) -> i32 { a + b }' },
      { name: 'complex', code: 'fn fibonacci(n: i32) -> i32 { if n <= 1 { n } else { fibonacci(n-1) + fibonacci(n-2) } }' }
    ];

    for (const { name, code } of testCases) {
      const start = performance.now();
      const result = wasmModule.compile(code);
      const end = performance.now();

      const duration = end - start;

      // Compilation should be fast
      expect(duration).toBeLessThan(100); // 100ms max
      expect(result).toBeTruthy();

      console.log(`${name} compilation: ${duration.toFixed(2)}ms`);
    }
  });

  test('memory allocation stress test', async () => {
    const iterations = 1000;
    const allocSize = 1024; // 1KB per allocation

    // Baseline memory if available
    const baseline = performance.memory?.usedJSHeapSize || 0;

    // Stress test memory allocation
    for (let i = 0; i < iterations; i++) {
      const data = new Uint8Array(allocSize);
      data.fill(i % 256);

      // Simulate processing
      const processed = wasmModule.compile(`data_${i}`);
      expect(processed).toBeTruthy();
    }

    // Force GC
    if (global.gc) {
      global.gc();
      await new Promise(resolve => setTimeout(resolve, 100));
    }

    const final = performance.memory?.usedJSHeapSize || 0;
    const growth = final - baseline;

    // Memory growth should be reasonable
    const maxGrowth = 10 * 1024 * 1024; // 10MB
    expect(growth).toBeLessThan(maxGrowth);

    console.log(`Memory growth: ${(growth / 1024 / 1024).toFixed(2)}MB`);
  });

  test('concurrent compilation performance', async () => {
    const concurrentTasks = 10;
    const testCode = 'fn test() { println("concurrent test") }';

    const start = performance.now();

    const promises = Array.from({ length: concurrentTasks }, async (_, i) => {
      const result = wasmModule.compile(`${testCode} // Task ${i}`);
      return result;
    });

    const results = await Promise.all(promises);
    const end = performance.now();

    const totalTime = end - start;
    const avgTime = totalTime / concurrentTasks;

    expect(results).toHaveLength(concurrentTasks);
    expect(avgTime).toBeLessThan(50); // 50ms average per task

    console.log(`Concurrent compilation: ${totalTime.toFixed(2)}ms total, ${avgTime.toFixed(2)}ms average`);
  });

  test('load time performance', () => {
    // Test WASM module loading time (simulated)
    const start = performance.now();

    // Simulate module instantiation
    const moduleSize = wasmBytes.length;
    const loadTimeMs = moduleSize / (1024 * 1024) * 100; // Simulate 100ms per MB

    const end = start + loadTimeMs;
    const loadTime = end - start;

    // Load time should be reasonable for browser
    expect(loadTime).toBeLessThan(500); // 500ms max

    console.log(`Simulated load time: ${loadTime.toFixed(2)}ms for ${(moduleSize / 1024).toFixed(1)}KB`);
  });

  test('API responsiveness under load', async () => {
    const requests = 100;
    const maxLatency = 10; // 10ms per request

    const latencies = [];

    for (let i = 0; i < requests; i++) {
      const start = performance.now();
      const isValid = wasmModule.validate(`test code ${i}`);
      const end = performance.now();

      const latency = end - start;
      latencies.push(latency);

      expect(isValid).toBe(true);
      expect(latency).toBeLessThan(maxLatency);
    }

    const avgLatency = latencies.reduce((a, b) => a + b, 0) / latencies.length;
    const maxObservedLatency = Math.max(...latencies);

    console.log(`API latency: ${avgLatency.toFixed(2)}ms avg, ${maxObservedLatency.toFixed(2)}ms max`);

    expect(avgLatency).toBeLessThan(5); // 5ms average
  });
});