package utils

import (
	"math/rand"
	"simple-memo/global"
	"simple-memo/models"
	"time"
)

const userCodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

func init() {
	rand.Seed(time.Now().UnixNano())
}

func GenerateUserCode() string {
	for {
		code := generateRandomCode(8)
		if isUserCodeUnique(code) {
			return code
		}
	}
}

func generateRandomCode(length int) string {
	result := make([]byte, length)
	for i := range result {
		result[i] = userCodeChars[rand.Intn(len(userCodeChars))]
	}
	return string(result)
}

func isUserCodeUnique(code string) bool {
	var count int64
	global.DB.Model(&models.User{}).Where("user_code = ?", code).Count(&count)
	return count == 0
}