namespace MeloongCore;
public static class PathUtils {

    /// <summary>
    /// 若路径较长，则尽量将其转换为短路径。
    /// 若输入的是文件夹路径，不保证其结尾是否有 \ 。
    /// </summary>
    public static string Shorten(string fullName, bool keepFileName = false) {
        if (string.IsNullOrEmpty(fullName) || fullName.Length <= 200) return fullName;
        fullName = fullName.Replace('/', '\\');

        // 保留文件名
        string pathToKeep = "";
        string pathToShorten = fullName;
        if (fullName.EndsWithF(".jar", true)) keepFileName = true; // jar 文件的文件名需要保留原样，否则会导致 Forge 1.20.1 无法通过文件名识别模块名
        if (keepFileName && File.Exists(fullName)) {
            pathToKeep = Path.GetFileName(fullName);
            pathToShorten = Path.GetDirectoryName(fullName);
        }

        // 逐级向上寻找已存在的文件夹，将不存在的部分挪到 suffix，不再缩短
        while (!Directory.Exists(pathToShorten) && !File.Exists(pathToShorten)) { // 如果路径不存在
            string parentPath = Path.GetDirectoryName(pathToShorten);
            if (string.IsNullOrEmpty(parentPath) || parentPath == pathToShorten) return fullName; // 已经到达根目录，全都不存在，直接返回
            pathToKeep = Path.Combine(Path.GetFileName(pathToShorten), pathToKeep);
            pathToShorten = parentPath;
        }
        if (pathToShorten.Length <= 10) return fullName;

        // 缩短路径
        var buffer = new StringBuilder(260);
        if (GetShortPathNameW(pathToShorten, buffer, buffer.Capacity) == 0) return fullName;
        return Path.Combine(buffer.ToString(), pathToKeep);
    }
    [DllImport("kernel32.dll", CharSet = CharSet.Unicode)]
    private static extern int GetShortPathNameW(string lpszLongPath, StringBuilder lpszShortPath, int cchBuffer);

}