using System.Text;

namespace Atomx.Utils.Extension
{
    public static class PathExtension
    {
        /// <summary>
        /// 是否是绝对路径
        /// windows下判断 路径是否包含 ":"
        /// Mac OS、Linux下判断 路径是否包含 "\"
        /// </summary>
        /// <param name="path"></param>
        /// <returns></returns>
        public static bool IsAbsolute(this string path)
        {
            return Path.VolumeSeparatorChar == ':' ? path.IndexOf(Path.VolumeSeparatorChar) > 0 : path.IndexOf('\\') > 0;
        }

        /// <summary>
        /// 获取文件绝对路径
        /// </summary>
        /// <param name="path"></param>
        /// <returns></returns>
        public static string MapPath(string root, string path)
        {

            return path.IsAbsolute() ? path : Path.Combine(root, path.TrimStart('~', '/').Replace('/', Path.DirectorySeparatorChar));
        }

        /// <summary>
        /// 检测指定路径是否存在
        /// </summary>
        /// <param name="path">路径</param>
        /// <param name="isDirectory">是否是目录</param>
        /// <returns></returns>
        public static bool IsExist(string root, string path, bool isDirectory)
        {
            if (isDirectory)
            {
                return Directory.Exists(path.IsAbsolute() ? path : MapPath(root, path));
            }
            else
            {
                return File.Exists(path.IsAbsolute() ? path : MapPath(root, path));
            }
        }


        /// <summary>
        /// 根据指定目录，当前日期和扩展名，获取一个完整的存储路径和名称
        /// </summary>
        /// <param name="path">指定存储文件根目录，默认 upload，</param>
        /// <param name="fixedpath">是否固定存储在根目录，如果不固定，将自动根据时间生成子文件夹进行存储</param>
        /// <param name="name">存储文件名，如果为空将自动生成文件名</param>
        /// <param name="extension">文件存储后缀，不能为空</param>
        /// <returns></returns>
        public static string GetFileNameByData(string path, bool fixedpath, string name, string extension)
        {
            if (string.IsNullOrEmpty(extension)) throw new ArgumentNullException("extension");
            if (!extension.StartsWith(".")) extension = "." + extension;

            if (string.IsNullOrEmpty(path))
            {
                path = "/uploads";
            }
            if (path.StartsWith("/")) path = path.Substring(1, path.Length - 1);
            if (path.EndsWith("/")) path = path.Substring(0, path.Length - 1);

            StringBuilder fileName = new StringBuilder(path);
            if (!fixedpath)
            {
                fileName.AppendFormat("/{0}/{1}/", DateTime.Now.ToString("yyyyMM"), DateTime.Now.ToString("dd"));
            }
            if (string.IsNullOrEmpty(name))
            {
                Random random = new Random(Guid.NewGuid().GetHashCode());
                fileName.Append(DateTime.Now.ToString("yyyyMMddHHmmss") + random.Next(1000, 10000));
            }
            else
            {
                fileName.Append("/" + name);
            }
            return fileName.ToString() + extension;
        }
    }
}