using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Linq;
using System.Net;
using System.Reflection;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using UpdateLib.Data;
using UpdateLib.UI;

namespace UpdateLib
{
    public class Updater : Component
    {
        private const String localUpdateFile = @".\UpdateInfo";
        public String UpdateUrl { get; set; }

        public void CheckForUpdates()
        {
            try
            {
                CleanUp();
                WebClient downloadclient = new WebClient();
                downloadclient.DownloadFile(UpdateUrl, localUpdateFile);
                downloadclient.Dispose();

                if(!File.Exists(localUpdateFile))
                {
                    throw new FileNotFoundException("Lokale Update datei ist beschädigt");
                }

                UpdateSaveFile localFile = DecodeSaveFile(localUpdateFile);

                Version localVersion = Assembly.GetEntryAssembly().GetName().Version;
                Version onlineVersion = Version.Parse(localFile.VersionString);

                if(onlineVersion > localVersion)
                {
                    string MsgBox = String.Format("Version {0} verfügbar",onlineVersion);
                    if(MessageBox.Show(MsgBox,"Update",MessageBoxButtons.YesNo) == DialogResult.Yes)
                    {
                        frmUpdater updateform = new frmUpdater(localFile,GetPath(UpdateUrl));
                        updateform.ShowDialog();
                    }
                }
                else
                {
                    MessageBox.Show(onlineVersion.ToString());
                    MessageBox.Show(localVersion.ToString());
                    MessageBox.Show("Software ist in der aktuellste Version");
                }
            }
            catch(Exception e)
            {
                //MessageBox.Show("Fehler beim uberprüfen von Updates\nVersuchen Sie später nochmal!\n\nFehlertext: " + e.Message, "Update", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }

        private string GetPath(string UpdateUrl)
        {
            StringBuilder sb = new StringBuilder();
            String[] updatePieces = UpdateUrl.Split('/');
            for(int i = 0; i < updatePieces.Length -1; i++)
            {
                sb.Append(updatePieces[i] + "/");
            }
            return sb.ToString();
        }

        private UpdateSaveFile DecodeSaveFile(string localUpdateFile)
        {
            FileStream localFileStream = null;
            BinaryFormatter decoder = null;

            try
            {
                localFileStream = File.Open(localUpdateFile, FileMode.Open, FileAccess.Read);
                decoder = new BinaryFormatter();
                return (UpdateSaveFile)decoder.Deserialize(localFileStream);
            }
            catch(Exception e)
            {
                throw new InvalidDataException("Der lokale updatedatei ist beschädigt "+e.Message);
            }
            finally
            {
                if (localFileStream != null)
                    localFileStream.Dispose();
            }
        }


        private void CleanUp()
        {
            DirectoryInfo di = new DirectoryInfo(Application.StartupPath);
            foreach (FileInfo fi in di.GetFiles("*.old", SearchOption.TopDirectoryOnly))
                fi.Delete();
            
        }
    }
}