package main

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"sync"
	"sync/atomic"
	"time"

	"code.tczkiot.com/seqlog"
)

func main() {
	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
		Level: slog.LevelInfo,
	}))

	fmt.Println("=== Seqlog 高并发示例 ===")
	fmt.Println("预计运行时间: 约 5 分钟")
	fmt.Println()
	totalStartTime := time.Now()

	// 清理并创建测试目录
	testDir := "test_concurrent"
	os.RemoveAll(testDir)
	if err := os.MkdirAll(testDir, 0755); err != nil {
		logger.Error("failed to create test directory", "error", err)
		return
	}
	defer os.RemoveAll(testDir)

	// 注册 3 个 topic，每个 topic 都有并发处理能力
	var processedCount atomic.Int64
	handler := func(rec *seqlog.Record) error {
		processedCount.Add(1)
		// 快速处理，无需模拟延迟
		return nil
	}

	// 创建 Seqlog 实例（默认处理器）
	seq := seqlog.NewLogHub(testDir, logger, nil)

	topics := []string{"app", "access", "error"}
	for _, topic := range topics {
		seq.RegisterHandlerWithConfig(topic, &seqlog.TopicConfig{
			Handler: handler,
		})
	}

	// 启动
	if err := seq.Start(); err != nil {
		logger.Error("failed to start seqlog", "error", err)
		return
	}
	defer seq.Stop()

	// ===== 场景 1: 并发写入不同 topic =====
	fmt.Println("场景 1: 并发写入测试（每个 goroutine 写入不同 topic）")
	fmt.Println("  - 3 个 topic，每个 topic 一个专用写入 goroutine")
	fmt.Println("  - 每个 goroutine 写入 2000 条消息")
	fmt.Println()

	startTime := time.Now()
	var writeWg sync.WaitGroup
	messagesPerTopic := 2000

	var totalWritten atomic.Int64
	var writeErrors atomic.Int64

	for i, topic := range topics {
		writeWg.Add(1)
		go func(topicName string, writerID int) {
			defer writeWg.Done()

			for j := 0; j < messagesPerTopic; j++ {
				data := fmt.Sprintf("topic-%s-msg-%d", topicName, j)

				_, err := seq.Write(topicName, []byte(data))
				if err != nil {
					writeErrors.Add(1)
					logger.Error("write failed", "topic", topicName, "msg", j, "error", err)
				} else {
					totalWritten.Add(1)
				}
			}
		}(topic, i)
	}

	writeWg.Wait()
	writeDuration := time.Since(startTime)

	fmt.Printf("写入完成:\n")
	fmt.Printf("  总消息数: %d\n", totalWritten.Load())
	fmt.Printf("  错误数: %d\n", writeErrors.Load())
	fmt.Printf("  耗时: %v\n", writeDuration)
	fmt.Printf("  吞吐量: %.0f msg/s\n\n", float64(totalWritten.Load())/writeDuration.Seconds())

	// 等待一段时间让消息被处理
	time.Sleep(2 * time.Second)

	// ===== 场景 2: 并发查询 =====
	fmt.Println("场景 2: 并发查询测试")
	fmt.Println("  - 20 个 goroutine 并发查询")
	fmt.Println("  - 每个 goroutine 执行 200 次查询操作")
	fmt.Println()

	startTime = time.Now()
	var queryWg sync.WaitGroup
	queryCount := 20
	queriesPerGoroutine := 200

	var totalQueries atomic.Int64
	var queryErrors atomic.Int64

	for i := range queryCount {
		queryWg.Add(1)
		go func(queryID int) {
			defer queryWg.Done()

			for j := range queriesPerGoroutine {
				// 随机选择一个 topic 进行查询
				topic := topics[j%len(topics)]

				processor, err := seq.GetProcessor(topic)
				if err != nil {
					queryErrors.Add(1)
					continue
				}

				// 获取记录总数
				count := processor.GetRecordCount()
				if count == 0 {
					continue
				}

				// 查询最新的 10 条记录
				querySize := min(count, 10)

				_, err = processor.QueryNewest(count-1, querySize)
				if err != nil {
					queryErrors.Add(1)
					logger.Error("query failed", "query", queryID, "error", err)
				} else {
					totalQueries.Add(1)
				}
			}
		}(i)
	}

	queryWg.Wait()
	queryDuration := time.Since(startTime)

	fmt.Printf("查询完成:\n")
	fmt.Printf("  总查询数: %d\n", totalQueries.Load())
	fmt.Printf("  错误数: %d\n", queryErrors.Load())
	fmt.Printf("  耗时: %v\n", queryDuration)
	fmt.Printf("  吞吐量: %.0f query/s\n\n", float64(totalQueries.Load())/queryDuration.Seconds())

	// ===== 场景 3: 混合读写 =====
	fmt.Println("场景 3: 混合读写测试")
	fmt.Println("  - 3 个写入 goroutine（每个 topic 一个），每个写入 1000 条消息")
	fmt.Println("  - 10 个查询 goroutine，每个执行 200 次查询")
	fmt.Println("  - 同时进行")
	fmt.Println()

	startTime = time.Now()
	var mixWg sync.WaitGroup

	var mixWriteCount atomic.Int64
	var mixQueryCount atomic.Int64

	// 启动写入 goroutine（每个 topic 一个专用 goroutine）
	for _, topic := range topics {
		mixWg.Add(1)
		go func(topicName string) {
			defer mixWg.Done()

			for j := range 1000 {
				data := fmt.Sprintf("mix-%s-msg-%d", topicName, j)

				if _, err := seq.Write(topicName, []byte(data)); err == nil {
					mixWriteCount.Add(1)
				}

				// 稍微降低写入速率
				time.Sleep(100 * time.Microsecond)
			}
		}(topic)
	}

	// 启动查询 goroutine
	for i := range 10 {
		mixWg.Add(1)
		go func(queryID int) {
			defer mixWg.Done()

			for j := range 200 {
				topic := topics[j%len(topics)]

				processor, err := seq.GetProcessor(topic)
				if err != nil {
					continue
				}

				count := processor.GetRecordCount()
				if count > 0 {
					if _, err := processor.QueryNewest(count-1, 5); err == nil {
						mixQueryCount.Add(1)
					}
				}

				time.Sleep(200 * time.Microsecond)
			}
		}(i)
	}

	mixWg.Wait()
	mixDuration := time.Since(startTime)

	fmt.Printf("混合操作完成:\n")
	fmt.Printf("  写入: %d 条消息\n", mixWriteCount.Load())
	fmt.Printf("  查询: %d 次\n", mixQueryCount.Load())
	fmt.Printf("  耗时: %v\n\n", mixDuration)

	// ===== 场景 4: 持续压测 =====
	fmt.Println("场景 4: 持续压测（运行 4 分钟）")
	fmt.Println("  - 3 个写入 goroutine 持续写入")
	fmt.Println("  - 5 个查询 goroutine 持续查询")
	fmt.Println("  - 实时显示进度")
	fmt.Println()

	stressTestDuration := 4 * time.Minute
	stressTestStart := time.Now()
	stressCtx, stressCancel := context.WithTimeout(context.Background(), stressTestDuration)
	defer stressCancel()

	var stressWriteCount atomic.Int64
	var stressQueryCount atomic.Int64
	var stressWg sync.WaitGroup

	// 持续写入 goroutine
	for _, topic := range topics {
		stressWg.Add(1)
		go func(topicName string) {
			defer stressWg.Done()
			msgCounter := 0

			for {
				select {
				case <-stressCtx.Done():
					return
				default:
					data := fmt.Sprintf("stress-%s-msg-%d", topicName, msgCounter)
					if _, err := seq.Write(topicName, []byte(data)); err == nil {
						stressWriteCount.Add(1)
						msgCounter++
					}
					time.Sleep(10 * time.Millisecond) // 控制写入速率
				}
			}
		}(topic)
	}

	// 持续查询 goroutine
	for i := range 5 {
		stressWg.Add(1)
		go func(queryID int) {
			defer stressWg.Done()

			for {
				select {
				case <-stressCtx.Done():
					return
				default:
					topic := topics[queryID%len(topics)]
					processor, err := seq.GetProcessor(topic)
					if err != nil {
						continue
					}

					count := processor.GetRecordCount()
					if count > 10 {
						if _, err := processor.QueryNewest(count-1, 10); err == nil {
							stressQueryCount.Add(1)
						}
					}
					time.Sleep(20 * time.Millisecond) // 控制查询速率
				}
			}
		}(i)
	}

	// 进度显示 goroutine
	stressWg.Go(func() {
		defer stressWg.Done()
		ticker := time.NewTicker(10 * time.Second)
		defer ticker.Stop()

		for {
			select {
			case <-stressCtx.Done():
				return
			case <-ticker.C:
				elapsed := time.Since(stressTestStart)
				fmt.Printf("  [进度] 已运行 %.0f 秒 - 写入: %d 条, 查询: %d 次\n",
					elapsed.Seconds(),
					stressWriteCount.Load(),
					stressQueryCount.Load())
			}
		}
	})

	stressWg.Wait()
	stressDuration := time.Since(stressTestStart)

	fmt.Printf("\n持续压测完成:\n")
	fmt.Printf("  运行时间: %v\n", stressDuration)
	fmt.Printf("  写入: %d 条消息\n", stressWriteCount.Load())
	fmt.Printf("  查询: %d 次\n", stressQueryCount.Load())
	fmt.Printf("  写入速率: %.0f msg/s\n", float64(stressWriteCount.Load())/stressDuration.Seconds())
	fmt.Printf("  查询速率: %.0f query/s\n\n", float64(stressQueryCount.Load())/stressDuration.Seconds())

	// ===== 场景 5: 统计信息汇总 =====
	fmt.Println("场景 5: 统计信息汇总")
	fmt.Println()

	var totalWriteCount, totalWriteBytes, totalProcessedCount, totalErrorCount int64
	for _, topic := range topics {
		processor, _ := seq.GetProcessor(topic)
		stats := processor.GetStats()

		fmt.Printf("Topic [%s]:\n", topic)
		fmt.Printf("  记录总数: %d\n", processor.GetRecordCount())
		fmt.Printf("  写入: %d 条, %d 字节\n", stats.WriteCount, stats.WriteBytes)
		fmt.Printf("  已处理: %d 条\n", stats.ProcessedCount)
		fmt.Printf("  处理错误: %d 次\n", stats.ErrorCount)
		if !stats.LastWriteTime.IsZero() {
			fmt.Printf("  最后写入: %v\n", stats.LastWriteTime.Format("15:04:05"))
		}
		fmt.Println()

		totalWriteCount += stats.WriteCount
		totalWriteBytes += stats.WriteBytes
		totalProcessedCount += stats.ProcessedCount
		totalErrorCount += stats.ErrorCount
	}

	fmt.Printf("总计:\n")
	fmt.Printf("  写入: %d 条, %d 字节\n", totalWriteCount, totalWriteBytes)
	fmt.Printf("  已处理: %d 条\n", totalProcessedCount)
	fmt.Printf("  处理错误: %d 次\n", totalErrorCount)
	fmt.Println()

	// 等待所有消息处理完成
	fmt.Println("等待消息处理...")
	maxWait := 5 * time.Second
	checkInterval := 100 * time.Millisecond
	elapsed := time.Duration(0)

	for elapsed < maxWait {
		processed := processedCount.Load()
		if processed >= totalWriteCount {
			break
		}
		time.Sleep(checkInterval)
		elapsed += checkInterval
	}

	fmt.Printf("处理完成: %d/%d 条消息\n", processedCount.Load(), totalWriteCount)

	totalDuration := time.Since(totalStartTime)
	fmt.Printf("\n=== 所有测试完成 ===\n\n")

	fmt.Println("场景耗时总结:")
	fmt.Printf("  场景 1 (并发写入):     %v\n", writeDuration)
	fmt.Printf("  场景 2 (并发查询):     %v\n", queryDuration)
	fmt.Printf("  场景 3 (混合读写):     %v\n", mixDuration)
	fmt.Printf("  场景 4 (持续压测):     %v\n", stressDuration)
	fmt.Printf("  总运行时间:           %v (%.1f 分钟)\n", totalDuration, totalDuration.Minutes())
}