package main

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"sync"
	"sync/atomic"
	"time"
)

// 压测配置
type BenchConfig struct {
	URL         string        // 测试URL
	Concurrency int           // 并发数
	Duration    time.Duration // 持续时间
	Timeout     time.Duration // 请求超时时间
}

// 压测结果
type BenchResult struct {
	TotalRequests   int64         // 总请求数
	SuccessRequests int64         // 成功请求数
	FailedRequests  int64         // 失败请求数
	TotalDuration   time.Duration // 总耗时
	MinLatency      time.Duration // 最小延迟
	MaxLatency      time.Duration // 最大延迟
	AvgLatency      time.Duration // 平均延迟
	QPS             float64       // 每秒请求数
}

func main() {
	fmt.Println("==========================================")
	fmt.Println("  HoTime 框架性能压力测试")
	fmt.Println("==========================================")
	fmt.Println()

	// 测试配置
	configs := []BenchConfig{
		{
			URL:         "http://127.0.0.1:8081/app/test/hello",
			Concurrency: 10,
			Duration:    10 * time.Second,
			Timeout:     5 * time.Second,
		},
		{
			URL:         "http://127.0.0.1:8081/app/test/hello",
			Concurrency: 50,
			Duration:    10 * time.Second,
			Timeout:     5 * time.Second,
		},
		{
			URL:         "http://127.0.0.1:8081/app/test/hello",
			Concurrency: 100,
			Duration:    10 * time.Second,
			Timeout:     5 * time.Second,
		},
		{
			URL:         "http://127.0.0.1:8081/app/test/hello",
			Concurrency: 200,
			Duration:    10 * time.Second,
			Timeout:     5 * time.Second,
		},
	}

	// 先检查服务是否可用
	fmt.Println("正在检查服务是否可用...")
	if !checkService(configs[0].URL) {
		fmt.Println("❌ 服务不可用，请先启动示例应用：")
		fmt.Println("   cd example && go run main.go")
		return
	}
	fmt.Println("✅ 服务已就绪")
	fmt.Println()

	// 执行压测
	for i, config := range configs {
		fmt.Printf("【测试 %d】并发数: %d, 持续时间: %v\n", i+1, config.Concurrency, config.Duration)
		fmt.Println("------------------------------------------")

		result := runBenchmark(config)
		printResult(result)
		fmt.Println()

		// 测试间隔，让服务恢复
		if i < len(configs)-1 {
			fmt.Println("等待 3 秒后开始下一轮测试...")
			time.Sleep(3 * time.Second)
			fmt.Println()
		}
	}

	fmt.Println("==========================================")
	fmt.Println("  压力测试完成")
	fmt.Println("==========================================")
}

// 检查服务是否可用
func checkService(url string) bool {
	client := &http.Client{Timeout: 3 * time.Second}
	resp, err := client.Get(url)
	if err != nil {
		return false
	}
	defer resp.Body.Close()
	return resp.StatusCode == 200
}

// 执行压测
func runBenchmark(config BenchConfig) BenchResult {
	var (
		totalRequests   int64
		successRequests int64
		failedRequests  int64
		totalLatency    int64 // 纳秒
		minLatency      int64 = int64(time.Hour)
		maxLatency      int64
		mu              sync.Mutex
	)

	// 创建HTTP客户端
	client := &http.Client{
		Timeout: config.Timeout,
		Transport: &http.Transport{
			MaxIdleConns:        config.Concurrency * 2,
			MaxIdleConnsPerHost: config.Concurrency * 2,
			IdleConnTimeout:     90 * time.Second,
		},
	}

	// 控制退出
	done := make(chan struct{})
	var wg sync.WaitGroup

	startTime := time.Now()

	// 启动并发goroutine
	for i := 0; i < config.Concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()

			for {
				select {
				case <-done:
					return
				default:
					reqStart := time.Now()
					success := makeRequest(client, config.URL)
					latency := time.Since(reqStart).Nanoseconds()

					atomic.AddInt64(&totalRequests, 1)
					atomic.AddInt64(&totalLatency, latency)

					if success {
						atomic.AddInt64(&successRequests, 1)
					} else {
						atomic.AddInt64(&failedRequests, 1)
					}

					// 更新最小/最大延迟
					mu.Lock()
					if latency < minLatency {
						minLatency = latency
					}
					if latency > maxLatency {
						maxLatency = latency
					}
					mu.Unlock()
				}
			}
		}()
	}

	// 等待指定时间
	time.Sleep(config.Duration)
	close(done)
	wg.Wait()

	totalDuration := time.Since(startTime)

	// 计算结果
	result := BenchResult{
		TotalRequests:   totalRequests,
		SuccessRequests: successRequests,
		FailedRequests:  failedRequests,
		TotalDuration:   totalDuration,
		MinLatency:      time.Duration(minLatency),
		MaxLatency:      time.Duration(maxLatency),
	}

	if totalRequests > 0 {
		result.AvgLatency = time.Duration(totalLatency / totalRequests)
		result.QPS = float64(totalRequests) / totalDuration.Seconds()
	}

	return result
}

// 发起单个请求
func makeRequest(client *http.Client, url string) bool {
	resp, err := client.Get(url)
	if err != nil {
		return false
	}
	defer resp.Body.Close()

	// 读取响应体
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return false
	}

	// 验证响应
	if resp.StatusCode != 200 {
		return false
	}

	// 验证JSON格式
	var result map[string]interface{}
	if err := json.Unmarshal(body, &result); err != nil {
		return false
	}

	// 验证返回状态
	if status, ok := result["status"].(float64); !ok || status != 0 {
		return false
	}

	return true
}

// 打印结果
func printResult(result BenchResult) {
	successRate := float64(result.SuccessRequests) / float64(result.TotalRequests) * 100

	fmt.Printf("总请求数:     %d\n", result.TotalRequests)
	fmt.Printf("成功请求:     %d\n", result.SuccessRequests)
	fmt.Printf("失败请求:     %d\n", result.FailedRequests)
	fmt.Printf("成功率:       %.2f%%\n", successRate)
	fmt.Printf("总耗时:       %v\n", result.TotalDuration.Round(time.Millisecond))
	fmt.Printf("QPS:          %.2f 请求/秒\n", result.QPS)
	fmt.Printf("最小延迟:     %v\n", result.MinLatency.Round(time.Microsecond))
	fmt.Printf("最大延迟:     %v\n", result.MaxLatency.Round(time.Microsecond))
	fmt.Printf("平均延迟:     %v\n", result.AvgLatency.Round(time.Microsecond))

	// 性能评级
	fmt.Print("性能评级:     ")
	switch {
	case result.QPS >= 10000:
		fmt.Println("🚀 优秀 (QPS >= 10000)")
	case result.QPS >= 5000:
		fmt.Println("⭐ 良好 (QPS >= 5000)")
	case result.QPS >= 2000:
		fmt.Println("👍 中等 (QPS >= 2000)")
	case result.QPS >= 1000:
		fmt.Println("📊 一般 (QPS >= 1000)")
	default:
		fmt.Println("⚠️ 需优化 (QPS < 1000)")
	}
}