// Package monitor 提供系统资源监控（CPU/内存/磁盘/网络/进程/连接/主机），后台定时采集，GetInfo 随时取最新快照。
package monitor

import (
	"fmt"
	"sync"
	"time"
)

// MonInfo 全量监控信息快照
type MonInfo struct {
	Host    HostInfo      `json:"host"`
	Cpu     CpuInfo       `json:"cpu"`
	Mem     MemInfo       `json:"mem"`
	Load    LoadInfo      `json:"load"`
	Process []ProcessInfo `json:"process"`
	Disk    []DiskInfo    `json:"disk"`
	Net     []NetInfo     `json:"net"`
	Conn    NetConnInfo   `json:"conn"`
	Ver     string        `json:"ver"`
}

// MonInfoSimple 精简版监控信息（适合定时上报）
type MonInfoSimple struct {
	Host HostInfo       `json:"host"`
	Cpu  CpuInfoLite    `json:"cpu"`
	Mem  MemInfo        `json:"mem"`
	Load LoadInfo       `json:"load"`
	Conn NetConnInfo    `json:"conn"`
	Net  NetInfoLite    `json:"net"`
	Disk []DiskInfoLite `json:"disk"`
	Ver  string         `json:"ver"`
}

var (
	interval int = 1
	monInfo  MonInfo
	mux      sync.Mutex
	one      sync.Once
)

// Start 启动后台采集
// 普通信息每秒刷新，主机/连接信息每 5 秒刷新一次；ver 为程序版本号
func Start(ver string) {
	monInfo.Ver = ver
	one.Do(proc)
}

// GetInfo 获取最新的监控信息快照
func GetInfo() MonInfo {
	mux.Lock()
	info := monInfo
	mux.Unlock()
	return info
}

// proc 监控采集主循环
func proc() {

	go func() {
		var i uint64 = 0
		// CPU信息应该不会变，CPU热插拨除外
		{
			cpuBaseVal, _ := getCpuInfo()
			monInfo.Cpu.Core = cpuBaseVal.Core
			monInfo.Cpu.Logic = cpuBaseVal.Logic
			monInfo.Cpu.Info = cpuBaseVal.Info
			monInfo.Cpu.Core = cpuBaseVal.Core
		}

		// 循环获取信息
		for {
			i = i + uint64(interval)

			//每次都获取
			diskVal, err := getDiskInfo()
			if err != nil {
				fmt.Println("获取硬盘信出错:", err.Error())
			}
			cpuUsedVal, _ := getCpuUsed()
			memVal, _ := getMemInfo()
			netVal, _ := getNetInfo()
			loadVal, _ := getLoadInfo()
			process, _ := GetProcessInfo()

			mux.Lock()
			//只获取CPU使用率，CPU基本信息一般不会发生改变
			monInfo.Cpu.UsedPercent = cpuUsedVal.UsedPercent
			monInfo.Cpu.Used = cpuUsedVal.Used
			monInfo.Load = loadVal
			monInfo.Disk = diskVal
			monInfo.Mem = memVal
			monInfo.Net = netVal
			monInfo.Process = process
			mux.Unlock()

			// 间隔5次调用一次 		// 建议60秒获取一次，例如更改计算机名，导致获取不准确
			if i%5 == 0 {
				hostVal, _ := getHostInfo()
				connVal, _ := getNetConnInfo()

				mux.Lock()
				monInfo.Host = hostVal
				monInfo.Conn = connVal
				mux.Unlock()
			}

			time.Sleep(time.Second * time.Duration(interval))
		}
	}()

}

// ToLiteInfo 将全量信息转换为精简版
func ToLiteInfo(info MonInfo) MonInfoSimple {
	lite := MonInfoSimple{}

	lite.Host = info.Host
	lite.Load = info.Load
	lite.Mem = info.Mem
	lite.Conn = info.Conn

	lite.Cpu.Core = info.Cpu.Core
	lite.Cpu.Logic = info.Cpu.Logic
	lite.Cpu.UsedPercent = info.Cpu.UsedPercent
	lite.Cpu.Logic = info.Cpu.Logic

	lite.Cpu.Name = make([]string, len(info.Cpu.Info))
	for index, c := range info.Cpu.Info {
		lite.Cpu.Name[index] = c.ModelName
	}

	lite.Disk = make([]DiskInfoLite, len(info.Disk))
	for index, d := range info.Disk {
		lite.Disk[index].Device = d.Device
		lite.Disk[index].MountPoint = d.MountPoint
		lite.Disk[index].UsedPercent = d.UsedPercent
		lite.Disk[index].UsedVolume = d.UsedVolume
		lite.Disk[index].ReadBytes = d.ReadBytes
		lite.Disk[index].WriteBytes = d.WriteBytes
	}

	lite.Net = NetInfoLite{}
	for _, n := range info.Net {
		lite.Net.BytesSent += n.BytesSent
		lite.Net.BytesRecv += n.BytesRecv
		lite.Net.PacketsSent += n.PacketsSent
		lite.Net.PacketsRecv += n.PacketsRecv
		lite.Net.TotalBytesSent += n.TotalBytesSent
		lite.Net.TotalBytesRecv += n.TotalBytesRecv
	}
	lite.Ver = info.Ver
	return lite
}

// 字节的单位转换 保留两位小数
func formatFileSize(fileSize uint64) (size string) {
	if fileSize < 1024 {
		//return strconv.FormatInt(fileSize, 10) + "B"
		return fmt.Sprintf("%.2fB", float64(fileSize)/float64(1))
	} else if fileSize < (1024 * 1024) {
		return fmt.Sprintf("%.2fKB", float64(fileSize)/float64(1024))
	} else if fileSize < (1024 * 1024 * 1024) {
		return fmt.Sprintf("%.2fMB", float64(fileSize)/float64(1024*1024))
	} else if fileSize < (1024 * 1024 * 1024 * 1024) {
		return fmt.Sprintf("%.2fGB", float64(fileSize)/float64(1024*1024*1024))
	} else if fileSize < (1024 * 1024 * 1024 * 1024 * 1024) {
		return fmt.Sprintf("%.2fTB", float64(fileSize)/float64(1024*1024*1024*1024))
	} else { //if fileSize < (1024 * 1024 * 1024 * 1024 * 1024 * 1024)
		return fmt.Sprintf("%.2fEB", float64(fileSize)/float64(1024*1024*1024*1024*1024))
	}
}