package public

import (
	"bytes"
	cr "crypto/rand"
	"math/big"
	"math/rand"
	"qfw/util/redis"
	"service/config"
	"strings"
	"sync"
	"time"
)

var VarLSCPool = &LSCPool{
	JobQueue:  make(chan string, config.Sysconfig.JobNum),
	WorkerNum: config.Sysconfig.WorkerNum,
	Lock:      &sync.Mutex{},
	Randoms:   "",
}

type LSCPool struct {
	JobQueue  chan string //待取的口令
	WorkerNum int         //当前工作的协程数
	Lock      *sync.Mutex //口令锁
	Randoms   string      //口令集合
}

func (this *LSCPool) GetJob() string {
	return <-this.JobQueue
}

var r *rand.Rand

func init() {
	r = rand.New(rand.NewSource(time.Now().Unix()))
	for i := 0; i < VarLSCPool.WorkerNum/2; i++ {
		go func() {
			for {
				VarLSCPool.JobQueue <- VarLSCPool.GetRandom()
			}
		}()
	}
}

//获取随机字符串
func (this *LSCPool) GetRandom() string {
	this.Lock.Lock()
	defer this.Lock.Unlock()
	//如果使用过了 重新获取
	for {
		LSC := this.SpecialChar(0) + this.LetterRandom(8)
		if strings.Contains(this.Randoms, LSC) {
			continue
		}
		this.Randoms += LSC + "|"
		ok, _ := redis.Exists("other", "DIS_"+LSC)
		if ok {
			continue
		}
		// log.Println("获取口令:", LSC)
		return LSC
	}
	return ""
}

//字母随机串
func (this *LSCPool) LetterRandom(LL int) (LR string) {
	bytes := make([]byte, LL)
	for i := 0; i < LL; i++ {
		b := r.Intn(26) + 65
		bytes[i] = byte(b)
	}
	LR = string(bytes)
	return
}

//特殊字符随机串
func (this *LSCPool) SpecialChar(LL int) (SC string) {
	var str = "$#"
	b := bytes.NewBufferString(str)
	length := b.Len()
	bigInt := big.NewInt(int64(length))
	for i := 0; i < LL; i++ {
		randomInt, _ := cr.Int(cr.Reader, bigInt)
		SC += string(str[randomInt.Int64()])
	}
	return
}