package logger

import (
	"log"
	"sync"
	"time"

	"gorm.io/gorm"
)

type LogTask struct {
	Timestamp int64
	Level     string
	Source    string
	Action    string
	Message   string
}

type LogWorkerPool struct {
	db            *gorm.DB
	taskChan      chan LogTask   // 任务通道
	workerCount   int            // 工作协程数量
	wg            sync.WaitGroup // 等待所有工作协程完成
	stopChan      chan struct{}  // 通知工作协程停止
	isClosing     bool           // 标记日志系统是否正在关闭
	batchSize     int            // 批量写入日志数量
	batchInterval time.Duration  // 批量写入间隔时间
}

// 实际执行日志写入的协程
func (p *LogWorkerPool) worker(id int) {
	defer p.wg.Done()

	log.Printf("日志工作协程 #%d 启动。", id)

	batch := make([]Log, 0, p.batchSize)      // 用于存储当前批次的日志
	ticker := time.NewTicker(p.batchInterval) // 定时器，用于触发超时写入
	defer ticker.Stop()

	for {
		select {
		case task, ok := <-p.taskChan:
			if !ok {
				p.flushBatch(batch)
				return
			}

			dbLog := Log{
				Timestamp: task.Timestamp,
				Level:     task.Level,
				Source:    task.Source,
				Action:    task.Action,
				Message:   task.Message,
			}
			batch = append(batch, dbLog)

			// 批次达到指定大小则立即写入
			if len(batch) >= p.batchSize {
				p.flushBatch(batch)
				batch = make([]Log, 0, p.batchSize) // 重置批次
				ticker.Reset(p.batchInterval)       // 重置定时器
			}

		case <-ticker.C:
			// 定时器触发
			if len(batch) > 0 {
				p.flushBatch(batch)
				batch = make([]Log, 0, p.batchSize) // 重置批次
			}

		case <-p.stopChan: // 关闭通道
			for {
				select {
				case task, ok := <-p.taskChan:
					if !ok { // 通道已关闭且所有任务已处理
						p.flushBatch(batch) // 刷新剩余批次
						return
					}

					dbLog := Log{
						Timestamp: task.Timestamp,
						Level:     task.Level,
						Source:    task.Source,
						Action:    task.Action,
						Message:   task.Message,
					}
					batch = append(batch, dbLog)
					// 达到批次大小或通道为空时刷新
					if len(batch) >= p.batchSize || len(p.taskChan) == 0 {
						p.flushBatch(batch)
						batch = make([]Log, 0, p.batchSize)
					}
				default:
					p.flushBatch(batch)
					return
				}
			}
		}
	}
}

// 日志批量写入
func (p *LogWorkerPool) flushBatch(batch []Log) {
	if len(batch) == 0 {
		return
	}
	if result := p.db.CreateInBatches(batch, len(batch)); result.Error != nil {
		log.Printf("工作协程批量写入数据库日志失败, 批次大小: %d", len(batch))
	}
}

// 提交日志任务的公共接口
// 此函数会阻塞，直到日志任务被通道接收
func (p *LogWorkerPool) SubmitLog(level, source, action, message string) {
	if p.isClosing {
		log.Printf("日志系统正在关闭，无法提交日志: %s - %s", level, message)
		return
	}

	// 直接发送到通道，如果通道满则阻塞
	p.taskChan <- LogTask{
		Timestamp: time.Now().Unix(),
		Level:     level,
		Source:    source,
		Action:    action,
		Message:   message,
	}
}

// 关闭工作池
func (p *LogWorkerPool) Close() {
	p.isClosing = true // 标记正在关闭
	close(p.stopChan)  // 关闭停止通道
	p.wg.Wait()        // 等待所有工作协程完成其工作
	close(p.taskChan)  // 关闭任务通道
}

func NewLogWorkerPool(db *gorm.DB, workerCount, queueSize, batchSize int, batchInterval time.Duration) *LogWorkerPool {
	if workerCount <= 0 {
		workerCount = 1
	}
	if queueSize <= 0 {
		queueSize = 1000 // 默认队列大小
	}
	if batchSize <= 0 {
		batchSize = 50 // 默认批量大小
	}
	if batchInterval <= 0 {
		batchInterval = 5 * time.Second // 默认批量间隔
	}

	pool := &LogWorkerPool{
		db:            db,
		taskChan:      make(chan LogTask, queueSize),
		workerCount:   workerCount,
		stopChan:      make(chan struct{}),
		isClosing:     false,
		batchSize:     batchSize,
		batchInterval: batchInterval,
	}

	// 启动指定数量的工作协程
	for i := 0; i < workerCount; i++ {
		pool.wg.Add(1)
		go pool.worker(i + 1)
	}

	return pool
}