using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace SteamWare
{
  /// <summary>
  /// Gestione update applicazioni
  /// </summary>
  public class UpdateMan
  {
    /// <summary>
    /// Init classe
    /// </summary>
    protected UpdateMan()
    { }
    /// <summary>
    /// Init classe
    /// </summary>
    public static UpdateMan obj = new UpdateMan();
    /// <summary>
    /// Recupera l'ultima versione disponibile
    /// </summary>
    /// <param name="remoteUrl"></param>
    /// <returns></returns>
    public UpdateInfoEventArgs getUpdateInfo(string remoteUrl)
    {
      UpdateInfoEventArgs args = new UpdateInfoEventArgs();
      Version CurrentVersion;
      bool Mandatory;
      XmlDocument recXml = new XmlDocument();
      try
      {
        // recupero dati
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.CreateHttp(remoteUrl);
        HttpWebResponse remData = (HttpWebResponse)request.GetResponse();
        // converto in XML
        recXml.Load(remData.GetResponseStream());
        XmlNodeList recData = recXml.SelectNodes("item");
        if (recData != null)
        {
          foreach (XmlNode item in recData)
          {
            XmlNode appCastVersion = item.SelectSingleNode("version");
            Version.TryParse(appCastVersion?.InnerText, out CurrentVersion);
            args.CurrentVersion = CurrentVersion;
            XmlNode appCastChangeLog = item.SelectSingleNode("changelog");
            args.ChangelogURL = appCastChangeLog?.InnerText;
            XmlNode appCastUrl = item.SelectSingleNode("url");
            args.DownloadURL = appCastUrl?.InnerText;
            XmlNode mandatory = item.SelectSingleNode("mandatory");
            Boolean.TryParse(mandatory?.InnerText, out Mandatory);
            args.Mandatory = Mandatory;
            args.IsUpdateAvailable = true;
          }
        }
      }
      catch
      {
        // metto versione = 0 + errore...
        args.IsUpdateAvailable = false;
        args.CurrentVersion= new Version("0.0.0.0");
      }
      return args;
    }
    /// <summary>
    /// Effettua download ultima versione applicativo
    /// </summary>
    /// <param name="remoteUrl"></param>
    /// <param name="localRepo"></param>
    /// <param name="packName"></param>
    public int downloadLatest(string remoteUrl, string localRepo, string packName)
    {
      int done = 0;
      // verifico directory
      if (!Directory.Exists(localRepo))
      {
        Directory.CreateDirectory(localRepo);
      }
      string localFile = "";
      string localLast = "";
      try
      {
        // in primis scarico update info...
        UpdateInfoEventArgs updateData = getUpdateInfo(remoteUrl);
        if (updateData.IsUpdateAvailable)
        {
          string DownloadURL = updateData.DownloadURL;
          localFile = string.Format(@"{0}\{2}_Build_{1}.zip", localRepo, updateData.CurrentVersion, packName);
          localLast = string.Format(@"{0}\{1}.zip", localRepo, packName);
          // scarica file e salva in directory locale...
          var client = new WebClient();
          client.DownloadFile(updateData.DownloadURL, localFile);
          // ora lo copio come latest...
          File.Copy(localFile, localLast, true);
          // indico come fatto!
          done = 1;
        }
        else
        {
          localFile = string.Format(@"{0}\Error.log", localRepo);
          // scrivo file in area target...
          using (StreamWriter sw = File.AppendText(localFile))
          {
            sw.WriteLine(string.Format("{0:yyyy-MM-dd HH:mm:ss} ATTENZIONE! Installer NON disponibile | {1}", DateTime.Now, remoteUrl));
          }
        }
      }
      catch (Exception exc)
      {
        localFile = string.Format(@"{0}\Error.log", localRepo);
        // scrivo file in area target...
        using (StreamWriter sw = File.AppendText(localFile))
        {
          sw.WriteLine(string.Format("{0:yyyy-MM-dd HH:mm:ss} Errore in fase di download installers per {1}", DateTime.Now, remoteUrl));
          sw.WriteLine(exc.ToString());
        }
      }
      return done;
    }
  }
  /// <summary>
  ///     Object of this class gives you all the details about the update useful in handling the update logic yourself.
  /// </summary>
  public class UpdateInfoEventArgs : EventArgs
  {
    /// <summary>
    ///     If new update is available then returns true otherwise false.
    /// </summary>
    public bool IsUpdateAvailable { get; set; }

    /// <summary>
    ///     Download URL of the update file.
    /// </summary>
    public string DownloadURL { get; set; }

    /// <summary>
    ///     URL of the webpage specifying changes in the new update.
    /// </summary>
    public string ChangelogURL { get; set; }

    /// <summary>
    ///     Returns newest version of the application available to download.
    /// </summary>
    public Version CurrentVersion { get; set; }

    /// <summary>
    ///     Returns version of the application currently installed on the user's PC.
    /// </summary>
    public Version InstalledVersion { get; set; }

    /// <summary>
    ///     Shows if the update is required or optional.
    /// </summary>
    public bool Mandatory { get; set; }
  }
}