package lib

import (
	"fmt"
	"math"
	"math/rand"
	"regexp"
	"strings"
	"time"
)

// #取得随机字符串：通过打乱slice来操作
func GetRandstring(length int, char string, rand_x int64) string {
	if length < 1 {
		return ""
	}

	if len(char) <= 6 || len(char) <= length {
		char = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
	}

	charArr := strings.Split(char, "")
	ran := rand.New(rand.NewSource(time.Now().UnixMilli() + rand_x))

	l := len(charArr)
	for i := l - 1; i > 0; i-- {
		r := ran.Intn(i)
		charArr[r], charArr[i] = charArr[i], charArr[r]
	}
	rchar := charArr[:length]
	return strings.Join(rchar, "")
}

// 检查日期格式
func IsDateStr(date string) bool {
	if _, err := time.Parse("2006-01-02", date); err != nil {
		return false
	}
	return true
}

// 转化
func TimeStrToTime(T_time string) (time.Time, bool) {
	stamp, err := time.ParseInLocation("2006-01-02 15:04:05", T_time, time.Local) // +8
	if err != nil {
		return time.Time{}, false
	}

	return stamp, true
}

func TimeStrToTime2(T_time string) (time.Time, bool) {
	stamp, err := time.ParseInLocation("2006-01-02 15:04:05", T_time, time.Local) // +8
	if err != nil {
		return time.Time{}, false
	}

	return stamp, true
}

// 判断字符串是否为纯数字
func IsNumeric(str string) bool {
	// 定义一个正则表达式来匹配纯数字字符串
	re := regexp.MustCompile(`^\d+$`)
	return re.MatchString(str)
}

// 计算两个时间字符串之间的分钟差
func MinutesDifference(startTime, endTime string) (float64, error) {
	layout := "2006-01-02 15:04:05"

	st, err := time.Parse(layout, startTime)
	if err != nil {
		return 0, fmt.Errorf("error parsing timeStr1: %w", err)
	}

	et, err := time.Parse(layout, endTime)
	if err != nil {
		return 0, fmt.Errorf("error parsing timeStr2: %w", err)
	}
	duration := et.Sub(st)
	minutes := math.Ceil(duration.Minutes())
	return minutes, nil
}