// --------------------------------------------------------------------------------------------------------------------
// <copyright file="UpdateService.cs" company="HandBrake Project (http://handbrake.fr)">
//   This file is part of the HandBrake source code - It may be used under the terms of the GNU General Public License.
// </copyright>
// <summary>
//   The Update Service
// </summary>
// --------------------------------------------------------------------------------------------------------------------

namespace HandBrake.ApplicationServices.Services
{
    using System;
    using System.IO;
    using System.Net;
    using System.Threading;

    using HandBrake.ApplicationServices.Model.General;
    using HandBrake.ApplicationServices.Utilities;

    /// <summary>
    /// The Update Service
    /// </summary>
    public class UpdateService
    {
        /*
         * TODO: Refactor this to use Caliburn Invocation
         */ 

        /// <summary>
        /// Begins checking for an update to HandBrake.
        /// </summary>
        /// <param name="callback">
        /// The method that will be called when the check is finished.
        /// </param>
        /// <param name="debug">
        /// Whether or not to execute this in debug mode.
        /// </param>
        /// <param name="url">
        /// The url.
        /// </param>
        /// <param name="currentBuild">
        /// The current Build.
        /// </param>
        /// <param name="skipBuild">
        /// The skip Build.
        /// </param>
        public static void BeginCheckForUpdates(AsyncCallback callback, bool debug, string url, int currentBuild, int skipBuild)
        {
            ThreadPool.QueueUserWorkItem(delegate
                {
                    try
                    {
                        // Initialize variables
                        WebRequest request = WebRequest.Create(url);
                        WebResponse response = request.GetResponse();
                        AppcastReader reader = new AppcastReader();

                        // Get the data, convert it to a string, and parse it into the AppcastReader
                        reader.GetUpdateInfo(new StreamReader(response.GetResponseStream()).ReadToEnd());

                        // Further parse the information
                        string build = reader.Build;

                        int latest = int.Parse(build);
                        int current = currentBuild;
                        int skip = skipBuild;

                        // If the user wanted to skip this version, don't report the update
                        if (latest == skip)
                        {
                            UpdateCheckInformation info = new UpdateCheckInformation { NewVersionAvailable = false };
                            callback(new UpdateCheckResult(debug, info));
                            return;
                        }

                        UpdateCheckInformation info2 = new UpdateCheckInformation
                            {
                                NewVersionAvailable = latest > current,
                                DescriptionUrl = reader.DescriptionUrl,
                                DownloadFile = reader.DownloadFile,
                                Build = reader.Build,
                                Version = reader.Version,
                            };
                        callback(new UpdateCheckResult(debug, info2));
                    }
                    catch (Exception exc)
                    {
                        callback(new UpdateCheckResult(debug, new UpdateCheckInformation { Error = exc }));
                    }
                });
        }

        /// <summary>
        /// End Check for Updates
        /// </summary>
        /// <param name="result">
        /// The result.
        /// </param>
        /// <returns>
        /// Update Check information
        /// </returns>
        public static UpdateCheckInformation EndCheckForUpdates(IAsyncResult result)
        {
            return ((UpdateCheckResult)result).Result;
        }
    }
}