// 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.Linq;
using System.Windows;
using System.Windows.Threading;
using MsgReader;
using QuickLook.Common.Plugin;
using QuickLook.Plugin.HtmlViewer;

namespace QuickLook.Plugin.MailViewer
{
    public class Plugin : IViewer
    {
        private WebpagePanel _panel;
        private string _tmpDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

        public int Priority => 0;

        public void Init()
        {
        }

        public bool CanHandle(string path)
        {
            return !Directory.Exists(path) && new[] {".eml", ".msg"}.Any(path.ToLower().EndsWith);
        }

        public void Prepare(string path, ContextObject context)
        {
            context.PreferredSize = new Size {Width = 1000, Height = 600};
        }

        public void View(string path, ContextObject context)
        {
            _panel = new WebpagePanel();
            context.ViewerContent = _panel;
            context.Title = Path.GetFileName(path);

            _panel.NavigateToFile(ExtractMailBody(path));
            _panel.Dispatcher.Invoke(() => { context.IsBusy = false; }, DispatcherPriority.Loaded);
        }

        public void Cleanup()
        {
            GC.SuppressFinalize(this);

            _panel?.Dispose();
            _panel = null;

            if (Directory.Exists(_tmpDir))
                Directory.Delete(_tmpDir, true);
        }

        private string ExtractMailBody(string path)
        {
            _tmpDir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
            Directory.CreateDirectory(_tmpDir);

            var msg = new Reader();

            var files = msg.ExtractToFolder(path, _tmpDir, true);

            if (files.Length > 0 && !string.IsNullOrEmpty(files[0]))
                return files[0];

            throw new Exception($"{path} is not a valid msg file.");
        }
    }
}