// Copyright © 2017-2025 QL-Win Contributors
//
// This file is part of QuickLook program.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

using QuickLook.Common.Helpers;
using System;
using System.IO;
using System.Text;
using System.Xml.Linq;

namespace QuickLook.Plugin.ThumbnailViewer.Providors;

internal class PdnProvider : AbstractProvidor
{
    public override Stream ViewImage(string path)
    {
        try
        {
            using TextReader reader = new StreamReader(path, Encoding.UTF8);
            string line = reader.ReadLine();

            if (!line.StartsWith("PDN"))
                return null;

            int indexOfStart = line.IndexOf("<");
            int indexOfEnd = line.LastIndexOf(">");

            if (indexOfStart < 0 || indexOfEnd < 0)
                return null;

            string xml = line.Substring(indexOfStart, indexOfEnd - indexOfStart + 1);

            // <pdnImage>
            //   <custom>
            //     <thumb png="..." />
            //   </custom>
            // </pdnImage>
            XDocument doc = XDocument.Parse(xml);
            var pngBase64 = doc.Root
                ?.Element("custom")
                ?.Element("thumb")
                ?.Attribute("png")
                ?.Value;

            if (pngBase64 != null)
            {
                byte[] imageBytes = Convert.FromBase64String(pngBase64);
                MemoryStream ms = new(imageBytes);
                return ms;
            }

            return null;
        }
        catch (Exception e)
        {
            ProcessHelper.WriteLog(e.ToString());
            return null;
        }
    }
}