package service

import (
	commonConfig "cicv-data-closedloop/aarch64/pjisuv/common/config"
	masterConfig "cicv-data-closedloop/aarch64/pjisuv/master/package/config"
	"cicv-data-closedloop/common/config/c_log"
	"cicv-data-closedloop/common/domain"
	"cicv-data-closedloop/common/entity"
	"cicv-data-closedloop/common/util"
	"time"
)

// DiskClean 如果磁盘占用过高，则删除timeWindow和对应的文件
func DiskClean() {
	c_log.GlobalLogger.Info("启动timeWindow清理goroutine，根据缓存策略清理copy目录。")
	for {
		time.Sleep(1000 * time.Millisecond)
		bags, _ := util.ListAbsolutePathWithSuffixAndSort(commonConfig.CloudConfig.BagCopyDir, ".bag")
		if len(bags) == 0 {
			continue
		}
		/*
			TTL(0, "删除旧数据")；
			STOP(1, "停止缓存");
			LRU(2, "保留高优先级")
		*/
		policyToDescription := map[string]string{
			"TTL":  "删除旧数据",
			"STOP": "停止缓存",
			"LRU":  "保留高优先级",
		}
		// 1 获取磁盘占用
		diskUsed, _ := util.GetDiskUsed(commonConfig.CloudConfig.Disk.Name)
		if diskUsed > commonConfig.CloudConfig.Disk.Used {
			policy := commonConfig.PlatformConfig.TaskCachePolicy
			c_log.GlobalLogger.Errorf("磁盘占用 %v 超过 %v，触发删除规则 %v", diskUsed, commonConfig.CloudConfig.Disk.Used, policyToDescription[policy])
			if policy == "TTL" {
				// 1 获取时间窗口队列中的第二个
				if len(entity.TimeWindowConsumerQueue) > 2 {
					deleteTimeWindow(1)
				}
			} else if policy == "STOP" {
				// 2 获取时间窗口队列中的倒数第一个
				if len(entity.TimeWindowConsumerQueue) > 2 {
					deleteTimeWindow(len(entity.TimeWindowConsumerQueue) - 1)
				}
			} else if policy == "LRU" {
				// 3 获取优先级最低的时间窗口
				if len(entity.TimeWindowConsumerQueue) > 2 {
					indexToRemove := getIndexToRemoveForLRU()
					if indexToRemove != -1 {
						deleteTimeWindow(indexToRemove)
					}
				}
			} else {
				c_log.GlobalLogger.Error("未知的缓存策略：", policy)
			}
		}
	}
}

func deleteTimeWindow(indexToRemove int) {
	timeWindowToRemove := entity.TimeWindowConsumerQueue[indexToRemove]
	// 1 删除队列中的窗口。使用切片的特性删除指定位置的元素
	entity.TimeWindowConsumerQueueMutex.Lock()
	entity.TimeWindowConsumerQueue = append(entity.TimeWindowConsumerQueue[:indexToRemove], entity.TimeWindowConsumerQueue[indexToRemove+1:]...)
	entity.TimeWindowConsumerQueueMutex.Unlock()
	// 2 删除该窗口对应的文件目录。
	faultTime := timeWindowToRemove.FaultTime
	dir := domain.GetCopyDir(commonConfig.CloudConfig.BagCopyDir, faultTime)
	err := util.RemoveDir(dir)
	if err != nil {
		c_log.GlobalLogger.Error("删除目录", dir, "失败：", err)
	}
}

func getIndexToRemoveForLRU() int {
	lru := commonConfig.PlatformConfig.Lru
	i := len(lru) - 1
	for i >= 0 {
		for i2, window := range entity.TimeWindowConsumerQueue {
			for _, label := range window.Labels {
				value, _ := masterConfig.LabelMapTriggerId.Load(label)
				if value == lru[i] {
					return i2
				}
			}
		}
	}
	return -1
}