package taillog

import (
	"fmt"
	"logagent/etcd"
	"time"
)

var tskMgr *tailLogMgr

//tailTask管理者

type tailLogMgr struct {
	logEntry    []*etcd.LogEntry
	tskMap      map[string]*TailTask
	newConfChan chan []*etcd.LogEntry
}

func Init(logEntryConf []*etcd.LogEntry) {
	tskMgr = &tailLogMgr{
		logEntry:    logEntryConf, //把当前的日志收集项信息保存起来
		tskMap:      make(map[string]*TailTask, 32),
		newConfChan: make(chan []*etcd.LogEntry), //无缓冲区的通道
	}
	for _, logEntry := range logEntryConf {
		//logEntry: *etcd.LogEntry
		//要收集的日志文件的路径
		//初始化的时候启动了多少tailTask，需要记下来
		tailTask := NewTailTask(logEntry.Path, logEntry.Topic)
		mKey := fmt.Sprintf("%v_%v", logEntry.Topic, logEntry.Path)
		tskMgr.tskMap[mKey] = tailTask

	}
	go tskMgr.run()
}

// 监听自己的newConfChan 有了新的配置过来就做对应的处理

func (t *tailLogMgr) run() {
	for {
		select {
		case newConf := <-t.newConfChan:
			// 1.配置新增
			// 2.配置删除
			// 3.配置变更

			for _, conf := range newConf {
				mKey := fmt.Sprintf("%v_%v", conf.Topic, conf.Path)
				_, ok := t.tskMap[mKey]
				if !ok {
					//新增的
					tailTask := NewTailTask(conf.Path, conf.Topic)
					t.tskMap[mKey] = tailTask
				} else {
					//原来就有，不需要操作
					continue
				}
			}
			//找出t.tskMap有，但是newConf里没有的，删除
			for _, c1 := range t.logEntry { //从原来的配置中依次拿出配置项
				isDelete := true
				for _, c2 := range newConf { //去新的配置项中逐一进行比较
					if c1.Path == c2.Path && c1.Topic == c2.Topic {
						isDelete = false
						continue
					}
				}
				if isDelete {
					//把c1对应的tailTask停掉
					mKey := fmt.Sprintf("%v_%v", c1.Topic, c1.Path)
					t.tskMap[mKey].cancel()
				}
			}
			fmt.Printf("新的配置来了%v\n", newConf)
		default:
			time.Sleep(time.Second)
		}
	}
}

//向外暴露tskMgr的newConfChan

func NewConfChan() chan<- []*etcd.LogEntry {
	return tskMgr.newConfChan
}