// Copyright © 2017 Paddy Xu
// 
// 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 System;
using System.IO;
using System.IO.Compression;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Xml;
using QuickLook.Common.ExtensionMethods;
using QuickLook.Common.Plugin;

namespace QuickLook.Plugin.PluginInstaller
{
    public partial class PluginInfoPanel : UserControl
    {
        private readonly ContextObject _context;
        private readonly string _path;
        private string _namespace;

        public PluginInfoPanel(string path, ContextObject context)
        {
            InitializeComponent();

            // apply global theme
            Resources.MergedDictionaries[0].Clear();

            _path = path;
            _context = context;
            ReadInfo();

            btnInstall.Click += BtnInstall_Click;
        }

        private void BtnInstall_Click(object sender, RoutedEventArgs e)
        {
            btnInstall.Content = "Installing ...";
            btnInstall.IsEnabled = false;

            var t = DoInstall();
            t.ContinueWith(_ =>
                Dispatcher.BeginInvoke(new Action(() => btnInstall.Content = "Done! Please restart QuickLook.")));
            t.Start();
        }

        private Task DoInstall()
        {
            var targetFolder = Path.Combine(App.UserPluginPath, _namespace);
            return new Task(() =>
            {
                CleanUp();

                try
                {
                    ZipFile.ExtractToDirectory(_path, targetFolder);
                }
                catch (Exception ex)
                {
                    Dispatcher.BeginInvoke(new Action(() => description.Text = ex.Message));
                    Dispatcher.BeginInvoke(new Action(() => btnInstall.Content = "Installation failed."));
                    CleanUp();
                }
            });

            void CleanUp()
            {
                if (!Directory.Exists(targetFolder))
                {
                    Directory.CreateDirectory(targetFolder);
                    return;
                }

                try
                {
                    Directory.GetFiles(targetFolder, "*", SearchOption.AllDirectories)
                        .ForEach(file => File.Move(file,
                            Path.Combine(Path.GetDirectoryName(file), Guid.NewGuid() + ".to_be_deleted")));
                }
                catch (Exception ex)
                {
                    Dispatcher.BeginInvoke(new Action(() => description.Text = ex.Message));
                    Dispatcher.BeginInvoke(new Action(() => btnInstall.Content = "Installation failed."));
                }
            }
        }


        private void ReadInfo()
        {
            filename.Text = Path.GetFileNameWithoutExtension(_path);

            var xml = LoadXml(GetFileFromZip(_path, "QuickLook.Plugin.Metadata.config"));

            _namespace = GetString(xml, @"/Metadata/Namespace");

            var okay = _namespace != null && _namespace.StartsWith("QuickLook.Plugin.");

            filename.Text = okay ? _namespace : "Invalid plugin.";
            version.Text = "Version " + GetString(xml, @"/Metadata/Version", "not defined");
            description.Text = GetString(xml, @"/Metadata/Description", string.Empty);

            btnInstall.Visibility = okay ? Visibility.Visible : Visibility.Collapsed;
        }

        private static string GetString(XmlNode xml, string xpath, string def = null)
        {
            var n = xml?.SelectSingleNode(xpath);

            return n?.InnerText ?? def;
        }

        private static XmlDocument LoadXml(Stream data)
        {
            var doc = new XmlDocument();
            try
            {
                doc.Load(data);
                return doc;
            }
            catch (XmlException)
            {
                return null;
            }
        }

        private static MemoryStream GetFileFromZip(string archive, string entry)
        {
            var ms = new MemoryStream();

            try
            {
                using (var zip = ZipFile.Open(archive, ZipArchiveMode.Read))
                {
                    using (var s = zip?.GetEntry(entry)?.Open())
                    {
                        s?.CopyTo(ms);
                    }
                }
            }
            catch (Exception)
            {
                return ms;
            }

            ms.Position = 0;
            return ms;
        }
    }
}