package monitor

import (
	"backend/Type"
	"backend/client"
	"backend/middleware/alibaba"
	"backend/model"
	"backend/msg"
	"backend/util"
	"errors"
	"fmt"
	"net"
	"time"

	"google.golang.org/protobuf/encoding/protojson"
)

func UserAliveMonitor(AppId int) {
	for {
		curCount, yCount, err := util.CountDistinctUidLastHour()
		if err != nil {
			continue
		}

		if yCount > 0 {
			drop := float64(yCount-curCount) / float64(yCount)
			str := `
# **游戏数据监控异常**
- 项目名称: meowment
- 监控项名称: 用户存活监控<br/>
-------------------------
监控时间段: 	%s ~ %s<br/>
昨日活跃用户数: %d<br/>
当前活跃用户数: %d<br/>
用户流失率:   **%.2f%%**<br/>
<a>@所有人</a>
			`
			if drop >= 0.3 && (yCount-curCount) >= int64(10) {
				alibaba.SendAliveMsg("服务器报警", fmt.Sprintf(str,
					time.Now().Add(-time.Hour).Format("2006-01-02 15:04:05"),
					time.Now().Format("2006-01-02 15:04:05"),
					yCount,
					curCount,
					drop*100), "red")
			}
		}

		time.Sleep(time.Until(time.Now().Truncate(time.Hour).Add(time.Hour)))
	}
}

func ServerInfoMonitor() {
	for {
		time.Sleep(time.Second * 10)
		monitorServerInfo()
	}
}

func monitorServerInfo() {
	db := util.MPool.GetGameDB()
	var server []*Type.ServerInfo
	defer db.Close()
	err := db.Select(&server, "SELECT `AppId`, `ServerId`, `ServerName`, `Status`, `CreateTime`, `OpenServerTime`, `Host`, `Port` FROM server ")
	if err != nil {
		return
	}
	for _, v := range server {
		if v.Status == 2 || v.Status == 3 { // 维护中或停用跳过
			continue
		}
		go func(v *Type.ServerInfo) {
			if err := monitorServerByFallback(v); err != nil {
				markServerOffline(v.AppId, v.ServerId)
			}
		}(v)
	}
}

func monitorServerByFallback(v *Type.ServerInfo) error {
	// 默认优先使用第一种方式；失败后自动切换第二种，再反向回退第一种重试一次。
	firstErr := monitorServerByMethod1(v)
	if firstErr == nil {
		return nil
	}

	secondErr := monitorServerByMethod2(v)
	if secondErr == nil {
		return nil
	}

	if err := monitorServerByMethod1(v); err == nil {
		return nil
	}

	return fmt.Errorf("method1 and method2 both failed, method1Err=%v, method2Err=%v", firstErr, secondErr)
}

func monitorServerByMethod1(v *Type.ServerInfo) error {
	resp, err := client.GetServerInfo(v.AppId, v.ServerId, &msg.ReqServerInfo{})
	if err != nil {
		return err
	}

	latency, err := util.GetAddressLatency(v.Host, v.Port)
	if err != nil {
		return err
	}

	tmpDb := util.MPool.GetGameDB()
	defer tmpDb.Close()
	weight := util.GetServerWeight(resp)
	extra, _ := protojson.Marshal(resp)
	_, err = tmpDb.Exec("update server set Status=1, Online=?,free_mem=?,cpu=?,weight=?,latency=?,extra=? where AppId=? and ServerId=?", resp.PlayerNum, resp.Sys, resp.CPU, weight, latency, string(extra), v.AppId, v.ServerId)
	return err
}

func monitorServerByMethod2(v *Type.ServerInfo) error {
	address := fmt.Sprintf("%s:%d", v.Host, v.Port)
	timeout := 3 * time.Second
	start := time.Now()
	conn, err := net.DialTimeout("tcp", address, timeout)
	latency := time.Since(start).Milliseconds()
	if err != nil {
		return err
	}
	conn.Close()

	res, err := model.GetServerInfo(v.AppId, v.ServerId)
	if err != nil {
		return err
	}

	serverInfo, ok := res.(map[string]interface{})
	if !ok {
		return errors.New("invalid server info response type")
	}

	freeMem := util.Int(serverInfo["FreeMem"])
	usageMem := util.Int(serverInfo["Sys"])
	cpu := util.Int(serverInfo["CPU"])
	weight := calcServerWeight(freeMem, cpu)

	tmpDb := util.MPool.GetGameDB()
	defer tmpDb.Close()
	_, err = tmpDb.Exec("update server set Status=1, Online=?,free_mem=?,cpu=?,weight=?,latency=? where AppId=? and ServerId=?", util.Int(serverInfo["PlayerNum"]), usageMem, cpu, weight, latency, v.AppId, v.ServerId)
	return err
}

func calcServerWeight(freeMem int, cpu int) int {
	memCap := 8192 // 8GB as reference cap for normalization
	if freeMem < 0 {
		freeMem = 0
	}
	memScore := 0
	if freeMem >= memCap {
		memScore = 100
	} else {
		memScore = freeMem * 100 / memCap
	}

	if cpu < 0 {
		cpu = 0
	}
	if cpu > 100 {
		cpu = 100
	}
	cpuScore := 100 - cpu

	weight := (memScore*6 + cpuScore*4) / 10
	if weight < 0 {
		return 0
	}
	if weight > 100 {
		return 100
	}
	return weight
}

func markServerOffline(appID int, serverID int) {
	tmpDb := util.MPool.GetGameDB()
	defer tmpDb.Close()
	_, _ = tmpDb.Exec("update server set Status=0 where AppId=? and ServerId=?", appID, serverID)
}