using ICSharpCode.SharpZipLib.Zip;
using System;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace AutoUpdate
{
    public partial class UpdateForm : Form
    {
        private string _file;
        private string _fileName;
        private string _path;
        private CancellationTokenSource _cts = new CancellationTokenSource();

        public UpdateForm(string file)
        {
            InitializeComponent();
            this.StartPosition = FormStartPosition.CenterParent;
            this.Text += $" v{Assembly.GetExecutingAssembly().GetName().Version.ToString()}";
            this._file = file;
            this._fileName = Path.GetFileNameWithoutExtension(file);
            this._path = Path.GetDirectoryName(file);
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            if (MessageBox.Show("是否关闭当前运行实例进行更新？", "升级程序提示", MessageBoxButtons.OKCancel) == DialogResult.OK)
            {
                this.button2.Enabled = true;
                Task.Run(() =>
                {
                    this.StartUpdate();
                });
            }
            else
            {
                Application.Exit();
            }
        }

        private void StartUpdate()
        {
            try
            {
                var installZipFile = Path.Combine(this._path, "application.zip");
                //if (File.Exists(installZipFile))
                {
                    //0.关闭进程
                    var instances = Process.GetProcessesByName(_fileName);
                    this.Update(() =>
                    {
                        this.log.Text += "开始关闭实例";
                        this.log.Text += Environment.NewLine;
                    });
                    foreach (var item in instances)
                    {
                        item.Kill();
                    }
                    this.Update(() =>
                    {
                        this.log.Text += "关闭实例完成";
                        this.log.Text += Environment.NewLine;
                    });

                    //1.备份原有内容到backup
                    this.Update(() =>
                    {
                        this.log.Text += "开始备份文件";
                        this.log.Text += Environment.NewLine;
                    });
                    var folder = Path.Combine(_path, "backup");
                    if (Directory.Exists(folder))
                    {
                        Directory.Delete(folder, true);
                        Directory.CreateDirectory(folder);
                        this.Update(() =>
                        {
                            this.log.Text += "删除旧的备份文件完成";
                            this.log.Text += Environment.NewLine;
                        });
                    }
                    this.DirectoryCopy(this._path, folder);
                    //2.解压升级程序到当前文件夹
                    this.Update(() =>
                    {
                        this.log.Text += "开始解压新文件";
                        this.log.Text += Environment.NewLine;
                    });
                    this.UnZip(installZipFile);
                    //3.成功删除备份和升级文件
                    try
                    {
                        this.Update(() =>
                        {
                            this.log.Text += "删除升级文件";
                            this.log.Text += Environment.NewLine;
                        });
                        File.Delete(installZipFile);

                        this.Update(() =>
                        {
                            this.log.Text += "删除备份目录";
                            this.log.Text += Environment.NewLine;
                        });

                        Directory.Delete(folder, true);
                    }
                    catch (Exception ex)
                    {
                        this.Update(() =>
                        {
                            this.log.Text += ex.Message;
                            this.log.Text += Environment.NewLine;
                            this.log.Text += ex.StackTrace;
                            this.log.Text += Environment.NewLine;
                        });
                    }

                    Process.Start(this._file);
                    Application.Exit();
                }
            }
            catch (Exception ex)
            {
                this.Update(() =>
                {
                    this.log.Text += ex.Message;
                    this.log.Text += Environment.NewLine;
                    this.log.Text += ex.StackTrace;
                    this.log.Text += Environment.NewLine;
                });
                //4.失败还原备份
                //File.Delete(file);
            }
        }

        private void DirectoryCopy(string sourceDirName, string destDirName, bool copySubDirs = true)
        {
            if (sourceDirName == Path.Combine(this._path, "backup"))
            {
                return;
            }
            DirectoryInfo dir = new DirectoryInfo(sourceDirName);

            if (!dir.Exists)
            {
                throw new DirectoryNotFoundException("Source directory does not exist or could not be found: " + sourceDirName);
            }

            DirectoryInfo[] dirs = dir.GetDirectories();
            // If the destination directory doesn't exist, create it.
            if (!Directory.Exists(destDirName))
            {
                Directory.CreateDirectory(destDirName);
            }

            // Get the files in the directory and copy them to the new location.
            FileInfo[] files = dir.GetFiles();
            foreach (FileInfo file in files)
            {
                string temppath = Path.Combine(destDirName, file.Name);
                if (file.Name == "application.zip")
                {
                    continue;
                }
                this.Update(() =>
                {
                    this.log.Text += temppath + "开始备份";
                    this.log.Text += Environment.NewLine;
                });
                file.CopyTo(temppath, true);
                this.Update(() =>
                {
                    this.log.Text += temppath + "备份完成";
                    this.log.Text += Environment.NewLine;
                });
            }

            // If copying subdirectories, copy them and their contents to new location.
            if (copySubDirs)
            {
                foreach (DirectoryInfo subdir in dirs)
                {
                    string temppath = Path.Combine(destDirName, subdir.Name);
                    DirectoryCopy(subdir.FullName, temppath, copySubDirs);
                }
            }
        }

        private void UnZip(string file)
        {
            using (var s = new ZipInputStream(File.OpenRead(file)))
            {
                ZipEntry theEntry = null;
                while ((theEntry = s.GetNextEntry()) != null)
                {
                    var directoryName = Path.GetDirectoryName(theEntry.Name);
                    var fileName = Path.GetFileName(theEntry.Name);
                    if (directoryName.Length > 0)
                    {
                        Directory.CreateDirectory(directoryName);
                    }
                    if (fileName != String.Empty)
                    {
                        var entryName = theEntry.Name;
                        if (entryName == "ICSharpCode.SharpZipLib.dll")
                        {
                            continue;
                        }
                        this.Update(() =>
                        {
                            this.log.Text += entryName + "开始解压";
                            this.log.Text += Environment.NewLine;
                        });
                        using (FileStream streamWriter = File.Create(entryName))
                        {
                            int size = 2048;
                            byte[] data = new byte[2048];
                            while (true)
                            {
                                size = s.Read(data, 0, data.Length);
                                if (size > 0)
                                {
                                    streamWriter.Write(data, 0, size);
                                }
                                else
                                {
                                    break;
                                }
                            }
                        }

                        this.Update(() =>
                        {
                            this.log.Text += entryName + "解压完成";
                            this.log.Text += Environment.NewLine;
                        });
                    }
                }
            }
        }

        private void Update(Action function)
        {
            this.Invoke(function);
        }
    }
}