package utils

import (
	"crypto/rand"
	"fmt"
	"math/big"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"time"
)

// GetCurrentTime 获取当前时间的格式化字符串
func GetCurrentTime() string {
	return time.Now().Format("2006-01-02 15:04:05")
}

// FormatTimestamp 将时间戳转换为日期字符串
func FormatTimestamp(timestamp int64) string {
	t := time.Unix(timestamp, 0)
	return t.Format("2006-01-02")
}

// CreateDir 创建目录
func CreateDir(dirPath string) error {
	return os.MkdirAll(dirPath, 0755)
}

// ExtractFromRegex 使用正则表达式提取内容
func ExtractFromRegex(content, pattern string) (string, error) {
	re := regexp.MustCompile(pattern)
	matches := re.FindStringSubmatch(content)
	if len(matches) < 2 {
		return "", fmt.Errorf("no match found for pattern: %s", pattern)
	}
	return matches[1], nil
}

// TransformLink 将原始链接转换为可直接访问的链接
func TransformLink(originalLink string) string {
	// 删除 amp; 字符
	return strings.ReplaceAll(originalLink, "amp;", "")
}

// GenerateRandomString 生成随机字符串
func GenerateRandomString(length int) string {
	const charset = "0123456789"
	result := make([]byte, length)
	for i := range result {
		num, _ := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
		result[i] = charset[num.Int64()]
	}
	return string(result)
}

// EnsureParentDir 确保父目录存在
func EnsureParentDir(filePath string) error {
	parentDir := filepath.Dir(filePath)
	return CreateDir(parentDir)
}