package dao

import (
	"regexp"
	"strings"
	"yintai-api/base/global"

	"gorm.io/gorm"
)

func getDB(db ...*gorm.DB) *gorm.DB {
	if len(db) > 0 {
		return db[0]
	}

	return global.GetDB()
}

var sortCol = regexp.MustCompile(`^[A-Za-z_][A-Za-z0-9_]*$`)

func ezSort(a string) string {
	items := strings.Split(a, ",")
	parts := make([]string, 0, len(items))
	for _, item := range items {
		s := strings.Fields(item)
		if len(s) != 2 || !sortCol.MatchString(s[0]) {
			return ""
		}
		dir := strings.ToUpper(s[1])
		if dir != "ASC" && dir != "DESC" {
			return ""
		}
		parts = append(parts, "`"+s[0]+"` "+dir)
	}
	return strings.Join(parts, ",")
}