package integration

import (
	"runtime"
	"sync"
	"sync/atomic"
	"testing"
	"time"

	"github.com/noahlann/nnet/pkg/nnet"
	"github.com/stretchr/testify/assert"
)

// TestHighConcurrencyConnections 测试高并发连接
func TestHighConcurrencyConnections(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0", // 使用随机端口
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("ping", func(ctx nnet.Context) error {
			return ctx.Response().WriteBytes([]byte("pong\n"))
		})
	})
	defer CleanupTestServer(t, ts)

	// 并发连接数（提高并发量）
	concurrency := 500
	requestsPerConn := 20

	var successCount int64
	var errorCount int64
	var wg sync.WaitGroup

	startTime := time.Now()

	// 创建并发连接
	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func(id int) {
			defer wg.Done()

			client := NewTestClient(t, ts.Addr, nil)
			defer CleanupTestClient(t, client)

			ConnectTestClient(t, client)

			// 每个连接发送多个请求
			for j := 0; j < requestsPerConn; j++ {
				resp := RequestWithTimeout(t, client, []byte("ping"), 5*time.Second)
				if string(resp) == "pong\n" {
					atomic.AddInt64(&successCount, 1)
				} else {
					atomic.AddInt64(&errorCount, 1)
				}
			}
		}(i)
	}

	wg.Wait()
	duration := time.Since(startTime)

	totalRequests := int64(concurrency * requestsPerConn)
	successRate := float64(successCount) / float64(totalRequests) * 100

	t.Logf("压力测试结果:")
	t.Logf("  并发连接数: %d", concurrency)
	t.Logf("  每连接请求数: %d", requestsPerConn)
	t.Logf("  总请求数: %d", totalRequests)
	t.Logf("  成功请求数: %d", successCount)
	t.Logf("  失败请求数: %d", errorCount)
	t.Logf("  成功率: %.2f%%", successRate)
	t.Logf("  总耗时: %v", duration)
	t.Logf("  QPS (每秒请求数): %.2f", float64(totalRequests)/duration.Seconds())
	t.Logf("  TPS (每秒事务数): %.2f", float64(successCount)/duration.Seconds())
	t.Logf("  平均响应时间: %.2f ms", duration.Seconds()*1000/float64(totalRequests))
	t.Logf("  峰值并发连接: %d", concurrency)

	// 验证成功率应该大于95%
	assert.GreaterOrEqual(t, successRate, 95.0, "成功率应该大于95%%")
	assert.Equal(t, int64(0), errorCount, "不应该有错误")
}

// TestHighConcurrencyRequests 测试高并发请求（单连接）
// 注意：单连接并发存在技术限制：
// 1. TCP连接是串行的，多个goroutine同时读写会导致数据混乱
// 2. 客户端实现使用互斥锁，高并发时锁竞争成为瓶颈
// 3. 请求和响应的匹配可能出错
// 建议：单连接并发控制在较低水平（50-100），高并发应使用多连接
func TestHighConcurrencyRequests(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0", // 使用随机端口
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("echo", func(ctx nnet.Context) error {
			data := ctx.Request().Raw()
			return ctx.Response().WriteBytes(data)
		})
	})
	defer CleanupTestServer(t, ts)

	client := NewTestClient(t, ts.Addr, nil)
	defer CleanupTestClient(t, client)

	ConnectTestClient(t, client)

	// 并发请求数（单连接，降低到合理范围）
	// 注意：单连接并发建议控制在50-100，超过此范围可能导致数据混乱或锁竞争
	concurrency := 100
	message := []byte("echo")

	var successCount int64
	var errorCount int64
	var wg sync.WaitGroup

	startTime := time.Now()

	// 并发发送请求
	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()

			resp := RequestWithTimeout(t, client, message, 5*time.Second)
			if string(resp) == string(message) {
				atomic.AddInt64(&successCount, 1)
			} else {
				atomic.AddInt64(&errorCount, 1)
			}
		}()
	}

	wg.Wait()
	duration := time.Since(startTime)

	successRate := float64(successCount) / float64(concurrency) * 100

	t.Logf("高并发请求测试结果（单连接）:")
	t.Logf("  并发请求数: %d", concurrency)
	t.Logf("  成功请求数: %d", successCount)
	t.Logf("  失败请求数: %d", errorCount)
	t.Logf("  成功率: %.2f%%", successRate)
	t.Logf("  总耗时: %v", duration)
	t.Logf("  QPS (每秒请求数): %.2f", float64(concurrency)/duration.Seconds())
	t.Logf("  TPS (每秒事务数): %.2f", float64(successCount)/duration.Seconds())
	t.Logf("  平均响应时间: %.2f ms", duration.Seconds()*1000/float64(concurrency))
	t.Logf("  注意：单连接并发存在技术限制，建议使用多连接并发测试")

	// 验证成功率应该大于90%（单连接并发可能受到客户端实现限制）
	assert.GreaterOrEqual(t, successRate, 90.0, "成功率应该大于90%%（单连接并发可能受到客户端实现限制）")
}

// TestMemoryUsage 测试内存使用情况
func TestMemoryUsage(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0", // 使用随机端口
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("echo", func(ctx nnet.Context) error {
			data := ctx.Request().Raw()
			return ctx.Response().WriteBytes(data)
		})
	})
	defer CleanupTestServer(t, ts)

	// 记录初始内存
	runtime.GC()
	var m1, m2 runtime.MemStats
	runtime.ReadMemStats(&m1)

	// 创建多个连接并发送请求（提高并发量）
	concurrency := 200
	var wg sync.WaitGroup

	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()

			client := NewTestClient(t, ts.Addr, nil)
			defer CleanupTestClient(t, client)

			ConnectTestClient(t, client)

			// 发送多个请求
			for j := 0; j < 100; j++ {
				_ = RequestWithTimeout(t, client, []byte("echo"), 5*time.Second)
			}
		}()
	}

	wg.Wait()

	// 记录最终内存
	runtime.GC()
	runtime.ReadMemStats(&m2)

	// 计算内存增长
	memAlloc := m2.Alloc - m1.Alloc
	memTotalAlloc := m2.TotalAlloc - m1.TotalAlloc
	memMallocs := m2.Mallocs - m1.Mallocs

	t.Logf("内存使用测试结果:")
	t.Logf("  并发连接数: %d", concurrency)
	t.Logf("  每连接请求数: 100")
	t.Logf("  内存分配增长: %.2f MB", float64(memAlloc)/1024/1024)
	t.Logf("  总内存分配: %.2f MB", float64(memTotalAlloc)/1024/1024)
	t.Logf("  内存分配次数: %d", memMallocs)
	t.Logf("  当前内存使用: %.2f MB", float64(m2.Alloc)/1024/1024)
	t.Logf("  系统内存使用: %.2f MB", float64(m2.Sys)/1024/1024)

	// 验证内存使用合理（每个连接+请求应该小于1MB）
	maxExpectedMem := float64(concurrency) * 1.0 // 每个连接最多1MB
	assert.Less(t, float64(memAlloc)/1024/1024, maxExpectedMem, "内存使用应该合理")
}

// TestSustainedLoad 测试持续负载
func TestSustainedLoad(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0", // 使用随机端口
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("ping", func(ctx nnet.Context) error {
			return ctx.Response().WriteBytes([]byte("pong\n"))
		})
	})
	defer CleanupTestServer(t, ts)

	// 持续负载参数（提高并发量）
	duration := 10 * time.Second
	concurrency := 100
	requestInterval := 50 * time.Millisecond

	var successCount int64
	var errorCount int64
	var wg sync.WaitGroup
	stopCh := make(chan struct{})

	startTime := time.Now()

	// 启动并发客户端
	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()

			client := NewTestClient(t, ts.Addr, nil)
			defer CleanupTestClient(t, client)

			ConnectTestClient(t, client)

			ticker := time.NewTicker(requestInterval)
			defer ticker.Stop()

			for {
				select {
				case <-stopCh:
					return
				case <-ticker.C:
					resp := RequestWithTimeout(t, client, []byte("ping"), 5*time.Second)
					if string(resp) == "pong\n" {
						atomic.AddInt64(&successCount, 1)
					} else {
						atomic.AddInt64(&errorCount, 1)
					}
				}
			}
		}()
	}

	// 运行指定时间
	time.Sleep(duration)
	close(stopCh)
	wg.Wait()

	totalDuration := time.Since(startTime)
	totalRequests := successCount + errorCount
	successRate := float64(successCount) / float64(totalRequests) * 100

	t.Logf("持续负载测试结果:")
	t.Logf("  持续时间: %v", duration)
	t.Logf("  并发连接数: %d", concurrency)
	t.Logf("  请求间隔: %v", requestInterval)
	t.Logf("  总请求数: %d", totalRequests)
	t.Logf("  成功请求数: %d", successCount)
	t.Logf("  失败请求数: %d", errorCount)
	t.Logf("  成功率: %.2f%%", successRate)
	t.Logf("  总耗时: %v", totalDuration)
	t.Logf("  平均QPS (每秒请求数): %.2f", float64(totalRequests)/totalDuration.Seconds())
	t.Logf("  平均TPS (每秒事务数): %.2f", float64(successCount)/totalDuration.Seconds())
	t.Logf("  峰值并发连接: %d", concurrency)

	// 验证成功率应该大于95%
	assert.GreaterOrEqual(t, successRate, 95.0, "成功率应该大于95%%")
}

// TestLargeMessageStress 测试大消息压力
func TestLargeMessageStress(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0", // 使用随机端口
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("echo", func(ctx nnet.Context) error {
			data := ctx.Request().Raw()
			return ctx.Response().WriteBytes(data)
		})
	})
	defer CleanupTestServer(t, ts)

	client := NewTestClient(t, ts.Addr, nil)
	defer CleanupTestClient(t, client)

	ConnectTestClient(t, client)

	// 大消息大小（100KB，降低到合理范围）
	messageSize := 100 * 1024
	message := make([]byte, messageSize)
	for i := range message {
		message[i] = byte(i % 256)
	}
	// 注意：大消息测试使用echo路由，消息本身不包含路由匹配字符串
	// 需要在消息前添加路由标识
	echoMsg := append([]byte("echo"), message...)

	// 并发发送大消息（提高超时时间）
	concurrency := 30
	var successCount int64
	var errorCount int64
	var wg sync.WaitGroup

	startTime := time.Now()

	for i := 0; i < concurrency; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()

			// 大消息需要更长的超时时间（60秒）
			resp := RequestWithTimeout(t, client, echoMsg, 60*time.Second)
			// 响应应该包含原始消息（echo路由会返回原始数据）
			if len(resp) >= len(echoMsg) {
				atomic.AddInt64(&successCount, 1)
			} else {
				atomic.AddInt64(&errorCount, 1)
			}
		}()
	}

	wg.Wait()
	duration := time.Since(startTime)

	successRate := float64(successCount) / float64(concurrency) * 100
	// 计算吞吐量（使用实际消息大小）
	actualMessageSize := int64(len(echoMsg))
	throughput := float64(successCount*actualMessageSize) / duration.Seconds() / 1024 / 1024

	t.Logf("大消息压力测试结果:")
	t.Logf("  消息大小: %d bytes (%.2f KB)", messageSize, float64(messageSize)/1024)
	t.Logf("  并发数: %d", concurrency)
	t.Logf("  成功请求数: %d", successCount)
	t.Logf("  失败请求数: %d", errorCount)
	t.Logf("  成功率: %.2f%%", successRate)
	t.Logf("  总耗时: %v", duration)
	t.Logf("  吞吐量: %.2f MB/s", throughput)
	t.Logf("  QPS (每秒请求数): %.2f", float64(concurrency)/duration.Seconds())
	t.Logf("  TPS (每秒事务数): %.2f", float64(successCount)/duration.Seconds())
	t.Logf("  平均响应时间: %.2f ms", duration.Seconds()*1000/float64(concurrency))

	// 验证成功率应该大于90%（大消息可能更容易失败）
	assert.GreaterOrEqual(t, successRate, 90.0, "成功率应该大于90%%")
}

// TestMaxConcurrency 测试最大并发连接数（极限测试）
func TestMaxConcurrency(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0",
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("ping", func(ctx nnet.Context) error {
			return ctx.Response().WriteBytes([]byte("pong\n"))
		})
	})
	defer CleanupTestServer(t, ts)

	// 逐步增加并发数，找到最大并发
	maxConcurrency := 0
	successThreshold := 95.0

	for testConcurrency := 100; testConcurrency <= 2000; testConcurrency += 100 {
		var successCount int64
		var errorCount int64
		var wg sync.WaitGroup

		startTime := time.Now()

		// 创建并发连接
		for i := 0; i < testConcurrency; i++ {
			wg.Add(1)
			go func() {
				defer wg.Done()

				client := NewTestClient(t, ts.Addr, nil)
				defer CleanupTestClient(t, client)

				ConnectTestClient(t, client)

				// 每个连接发送一个请求
				resp := RequestWithTimeout(t, client, []byte("ping"), 5*time.Second)
				if string(resp) == "pong\n" {
					atomic.AddInt64(&successCount, 1)
				} else {
					atomic.AddInt64(&errorCount, 1)
				}
			}()
		}

		wg.Wait()
		duration := time.Since(startTime)

		totalRequests := int64(testConcurrency)
		successRate := float64(successCount) / float64(totalRequests) * 100
		qps := float64(totalRequests) / duration.Seconds()
		tps := float64(successCount) / duration.Seconds()

		t.Logf("并发数: %d, 成功率: %.2f%%, QPS: %.2f, TPS: %.2f, 耗时: %v", testConcurrency, successRate, qps, tps, duration)

		if successRate >= successThreshold {
			maxConcurrency = testConcurrency
		} else {
			// 如果成功率低于阈值，停止测试
			break
		}
	}

	t.Logf("最大并发连接数（成功率>=%.0f%%）: %d", successThreshold, maxConcurrency)
	assert.Greater(t, maxConcurrency, 0, "应该找到最大并发数")
}

// TestMaxQPS 测试最大QPS（极限测试）
func TestMaxQPS(t *testing.T) {
	cfg := &nnet.Config{
		Addr: "tcp://127.0.0.1:0",
		Codec: &nnet.CodecConfig{
			DefaultCodec: "plain",
		},
	}

	ts := StartTestServerWithRoutes(t, cfg, func(server nnet.Server) {
		server.Router().RegisterString("ping", func(ctx nnet.Context) error {
			return ctx.Response().WriteBytes([]byte("pong\n"))
		})
	})
	defer CleanupTestServer(t, ts)

	client := NewTestClient(t, ts.Addr, nil)
	defer CleanupTestClient(t, client)

	ConnectTestClient(t, client)

	// 测试不同并发请求数下的QPS
	maxQPS := 0.0
	maxTPS := 0.0
	bestConcurrency := 0

	for testConcurrency := 100; testConcurrency <= 2000; testConcurrency += 100 {
		var successCount int64
		var errorCount int64
		var wg sync.WaitGroup

		startTime := time.Now()

		// 并发发送请求
		for i := 0; i < testConcurrency; i++ {
			wg.Add(1)
			go func() {
				defer wg.Done()

				resp := RequestWithTimeout(t, client, []byte("ping"), 5*time.Second)
				if string(resp) == "pong\n" {
					atomic.AddInt64(&successCount, 1)
				} else {
					atomic.AddInt64(&errorCount, 1)
				}
			}()
		}

		wg.Wait()
		duration := time.Since(startTime)

		successRate := float64(successCount) / float64(testConcurrency) * 100
		qps := float64(testConcurrency) / duration.Seconds()
		tps := float64(successCount) / duration.Seconds()

		t.Logf("并发数: %d, 成功率: %.2f%%, QPS: %.2f, TPS: %.2f, 耗时: %v", testConcurrency, successRate, qps, tps, duration)

		if successRate >= 95.0 && qps > float64(maxQPS) {
			maxQPS = qps
			maxTPS = tps
			bestConcurrency = testConcurrency
		}

		// 如果成功率太低，停止测试
		if successRate < 80.0 {
			break
		}
	}

	t.Logf("最大QPS: %.2f, 最大TPS: %.2f (并发数: %d)", maxQPS, maxTPS, bestConcurrency)
	assert.Greater(t, maxQPS, 0.0, "应该找到最大QPS")
}