package public

import (
	"fmt"
	"sync"
)

func PageNumParse(pageNum, pageSize, maxNum int64) (num, size int64, err error) {
	if pageNum < 1 {
		pageNum = 1
	}
	if pageSize < 1 {
		pageSize = 1
	}
	if maxNum > 0 && pageNum*pageSize > maxNum {
		err = fmt.Errorf("超出检索限制")
	}
	num = pageNum
	size = pageSize
	return
}

func PageRange(num, min, max int64) int64 {
	if num < min {
		return min
	}
	if num > max {
		return max
	}
	return num
}

var (
	PLock *DocBuyLock
)

type DocBuyLock struct {
	sync.Mutex
	UserLock map[string]*sync.Mutex
}

func NewDocBuyLock() *DocBuyLock {
	return &DocBuyLock{
		UserLock: make(map[string]*sync.Mutex),
	}
}
func init() {
	PLock = NewDocBuyLock()
}

func GetNewDocBuyLock(str string) *sync.Mutex {
	PLock.Lock()
	if PLock.UserLock[str] == nil {
		PLock.UserLock[str] = &sync.Mutex{}
	}
	PLock.Unlock()
	return PLock.UserLock[str]
}