Pilz.Updating/Pilz.Updating.Client/UpdateClient.cs

using Microsoft.VisualBasic.CompilerServices;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;

namespace Pilz.Updating;

public class UpdateClient
{

    // E b v e n t s

    public event UpdateStatusChangedEventHandler UpdateStatusChanged;

    public delegate void UpdateStatusChangedEventHandler(UpdateStatus newStatus);

    public event DownloadingUpdateEventHandler DownloadingUpdate;

    public delegate void DownloadingUpdateEventHandler(UpdatePackageInfo pkg, CancelEventArgs e);

    public event InstallingUpdateEventHandler InstallingUpdate;

    public delegate void InstallingUpdateEventHandler(UpdatePackageInfo pkg, CancelEventArgs e);

    public event UpdateInstallerStartedEventHandler UpdateInstallerStarted;

    public delegate void UpdateInstallerStartedEventHandler();

    public event NoUpdatesFoundEventHandler NoUpdatesFound;

    public delegate void NoUpdatesFoundEventHandler();

    // F i e l d s

    private readonly Dictionary<UpdatePackageInfo, string> dicPackagePaths = [];
    private UpdateStatus curDownloadingStatus = UpdateStatus.Waiting;

    // P r o p e r t i e s

    public HttpClient WebClient { get; private set; } = new();
    public string UpdateUrl { get; private set; }
    public ApplicationVersion CurrentVersion { get; private set; }
    public Channels MinimumChannel { get; private set; }
    public UpdateInfo UpdateInfo { get; private set; } = null;
    public UpdatePackageInfo UpdatePackageInfo { get; private set; } = null;
    public bool AutoCloseHostApplication { get; set; } = false;
    public bool AutoRestartHostApplication { get; set; } = false;
    public string RestartHostApplicationArguments { get; set; }
    public string HostApplicationPath { get; set; } = string.Empty;
    public string ApplicationName { get; set; } = string.Empty;
    public bool InstallAsAdmin { get; set; } = false;
    public uint MillisecondsToWaitForHostApplicationToClose { get; set; } = 10000;
    public bool ForceClosingHostApplication { get; set; } = true;
    public bool UIDarkMode { get; set; } = false;

    // C o n s t r u c t o r s

    public UpdateClient(string updateUrl, ApplicationVersion currentVersion, Channels minimumChannel)
    {
        UpdateUrl = updateUrl;
        CurrentVersion = currentVersion;
        MinimumChannel = (Channels)Math.Max((int)minimumChannel, (int)currentVersion.Channel);
    }

    // E v e n t   M e t h o d s

    private bool RaiseDownloadingUpdate(UpdatePackageInfo pkg)
    {
        var e = new CancelEventArgs(false);
        DownloadingUpdate?.Invoke(pkg, e);
        return e.Cancel;
    }

    private bool RaiseInstallingUpdate(UpdatePackageInfo pkg)
    {
        var e = new CancelEventArgs(true);
        InstallingUpdate?.Invoke(pkg, e);
        return e.Cancel;
    }

    // U p d a t e   R o u t i n e s

    public async Task UpdateInteractive()
    {
        var latestVersion = await CheckForUpdate();
        if (latestVersion is null)
            NoUpdatesFound?.Invoke();
        else
            await UpdateInteractive(latestVersion);
    }

    public async Task UpdateInteractive(UpdatePackageInfo package)
    {
        if (!RaiseDownloadingUpdate(package) && await DownloadPackageAsync(package))
        {
            if (!RaiseInstallingUpdate(package))
                await InstallPackage(package);
        }
    }

    public void RaiseUpdateStatusChanged(UpdateStatus newStatus)
    {
        UpdateStatusChanged?.Invoke(newStatus);
    }

    // F e a t u r e s

    public async Task<UpdateInfo> GetUpdateInfo()
    {
        string str = await WebClient.GetStringAsync(UpdateUrl);
        var info = UpdateInfo.Parse(str);
        return info;
    }

    public async Task<UpdatePackageInfo> CheckForUpdate()
    {
        RaiseUpdateStatusChanged(UpdateStatus.Searching);
        UpdateInfo = await GetUpdateInfo();
        if (UpdateInfo is not null)
            return CheckForUpdate(UpdateInfo);
        else
            return null;
    }

    public UpdatePackageInfo CheckForUpdate(UpdateInfo updateInfo)
    {
        UpdatePackageInfo foundPkgInfo = null;
        var latestVersion = CurrentVersion;
        RaiseUpdateStatusChanged(UpdateStatus.Searching);
        foreach (UpdatePackageInfo pkgInfo in updateInfo.Packages)
        {
            if (pkgInfo.Version.Channel <= MinimumChannel && pkgInfo.Version > latestVersion)
            {
                foundPkgInfo = pkgInfo;
                latestVersion = pkgInfo.Version;
            }
        }

        UpdatePackageInfo = foundPkgInfo;
        return foundPkgInfo;
    }

    public async Task<bool> DownloadPackageAsync(UpdatePackageInfo package)
    {
        curDownloadingStatus = UpdateStatus.DownloadingPackage;
        RaiseUpdateStatusChanged(curDownloadingStatus);
        string dirPath = Path.Combine(MyPaths.GetMyAppDataPath(), Conversions.ToString(package.GetHashCode()));
        string zipPath = Path.Combine(dirPath, PackageFileNameDefinations.ZIP_PACKAGE_FILENAME);
        var dir = new DirectoryInfo(dirPath);
        try
        {
            // Ensure existing and empty directory for the Zip File
            if (dir.Exists)
                dir.Delete(true);

            dir.Create();

            // Download zip package
            using var zipFile = new FileStream(zipPath, FileMode.Create, FileAccess.ReadWrite);
            using var zipStream = await WebClient.GetStreamAsync(package.Packagelink);
            await zipStream.CopyToAsync(zipFile);

            // Remember path to package directory
            dicPackagePaths.Add(package, dirPath);
        }
        catch (Exception)
        {
            return false;
        }

        return true;
    }

    private async Task<FileInfo> DownloadUpdateInstaller()
    {
        curDownloadingStatus = UpdateStatus.DownloadingInstaller;
        RaiseUpdateStatusChanged(curDownloadingStatus);

        // Ensure update installer path is empty
        var installerDirPath = new DirectoryInfo(Path.Combine(MyPaths.GetMyAppDataPath(), "UpdateInstallerTool"));
        if (installerDirPath.Exists)
            installerDirPath.Delete(true);

        await Task.Delay(100);
        installerDirPath.Create();
        await Task.Delay(100);

        // Download update installer zip
        var installerZipPath = Path.Combine(installerDirPath.FullName, "UpdatenInstaller.zip");
        using (var installerZipFile = new FileStream(installerZipPath, FileMode.Create, FileAccess.ReadWrite))
        {
            using var installerZipStream = await WebClient.GetStreamAsync(UpdateInfo.UpdateInstallerLink);
            await installerZipStream.CopyToAsync(installerZipFile);
        }

        // Extract update installer
        var installerExtractPath = installerDirPath.CreateSubdirectory("extracted");
        ZipFile.ExtractToDirectory(installerZipPath, installerExtractPath.FullName);
        File.Delete(installerZipPath);

        // Get UpdateInstaller.exe file
        return installerExtractPath.EnumerateFiles("*.exe").FirstOrDefault();
    }

    private void StartUpdateInstaller(string packagePath, string installerPath)
    {
        RaiseUpdateStatusChanged(UpdateStatus.StartingInstaller);

        // Create update settings
        var myAppPath = IO.Extensions.GetExecutablePath();
        var updateConfig = new UpdateInstallerConfig
        {
            PackagePath = packagePath,
            RestartHostApplication = AutoRestartHostApplication,
            RestartHostApplicationArguments = AutoRestartHostApplication ? RestartHostApplicationArguments : string.Empty,
            ApplicationName = ApplicationName,
            HostApplicationPath = string.IsNullOrEmpty(HostApplicationPath) ? Path.GetDirectoryName(myAppPath) : HostApplicationPath,
            HostApplicationProcessPath = myAppPath,
            MillisecondsToWaitForHostApplicationToClose = MillisecondsToWaitForHostApplicationToClose,
            ForceClosingHostApplication = ForceClosingHostApplication,
            UIDarkMode = UIDarkMode
        };

        // Start UpdateInstaller
        var procStartInfo = new ProcessStartInfo
        {
            FileName = installerPath,
            Arguments = updateConfig.ToString(),
            UseShellExecute = false,
            Verb = InstallAsAdmin ? "runas" : string.Empty
        };
        Process.Start(procStartInfo);
        UpdateInstallerStarted?.Invoke();
    }

    public async Task<bool> InstallPackage(UpdatePackageInfo package)
    {
        if (dicPackagePaths.TryGetValue(package, out var packagePath))
        {
            // Download update installer
            var installerPath = await DownloadUpdateInstaller();

            // Start update installer
            StartUpdateInstaller(packagePath, installerPath.FullName);

            // Close Host Application
            if (AutoCloseHostApplication)
                Environment.Exit(Environment.ExitCode);

            return true;
        }

        return false;
    }
}