package netutil

import (
	"net"
	"net/url"
	"path"
	"strings"
)

func GetLocalIP() string {
	addrs, err := net.InterfaceAddrs()
	if err != nil {
		return ""
	}
	for _, address := range addrs {
		if ipnet, ok := address.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
			if ipnet.IP.To4() != nil {
				return ipnet.IP.String()
			}
		}
	}
	return ""
}

func MergeURL(baseURL, relativePath string) string {
	// 解析基础URL
	base, err := url.Parse(baseURL)
	if err != nil {
		return ""
	}

	// 如果相对路径是绝对URL，直接返回
	if strings.HasPrefix(relativePath, "http://") || strings.HasPrefix(relativePath, "https://") {
		return relativePath
	}

	// 合并路径
	mergedPath := path.Join(base.Path, relativePath)

	// 处理路径中的 ./ 和 ../
	mergedPath = path.Clean(mergedPath)

	// 确保路径以/开头（如果原始base.Path以/结尾）
	if strings.HasSuffix(base.Path, "/") && !strings.HasPrefix(mergedPath, "/") {
		mergedPath = "/" + mergedPath
	}

	// 更新URL的Path部分
	base.Path = mergedPath

	return base.String()
}