//using System.CommandLine;
using Serilog;
using Spectre.Console;
using System.IO.Compression;
using System.Text.Json;
using System.Security.Cryptography;
using System.Text;

namespace EdgeInstaller;

public static class EdgeInstall
{
    private static HttpClient _client = new HttpClient();

    private static readonly string DataDir =
        Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
                "ClosedLess",
                "EdgeInstall-Jankmode");

    public static async Task<int> Main()
    {
        // WARN: Hardcoded variables are bad m'kay...
        string Arch = "amd64";

        // Ensure DataDir exists.
        // NOTE: Directory.CreateDirectory will ALWAYS create the entire path
        Directory.CreateDirectory(DataDir);

        // TODO: wrap this code in foot detection since foot isn't detected properly
        // BUG: Report detection error to Spectre.Console (foot == xterm)
        // HACK: We have to force this right now for foot to work properly...
        AnsiConsole.Console.Profile.Capabilities.Ansi = true;

        Log.Logger = new LoggerConfiguration()
            .MinimumLevel.Debug()
            .WriteTo.File(".EdgeInstaller.Log") // Only ever log to the logfile
            .CreateLogger();

        var Release = AnsiConsole.Status()
            .Spinner(Spinner.Known.Dots)
            .SpinnerStyle(Style.Parse("green"))
            .StartAsync(
                    "Getting Latest Release data",
                    _ => GetRelease()
                    );

        string ReleaseString = await Release;
        Log.Debug("{rs}", ReleaseString);

        AnsiConsole.MarkupLine("[green]Attempting to decode release data now[/]");
        ReleaseData data = getReleaseData(ReleaseString);

        RenderReleaseTable(data);

        Arch = AnsiConsole.Prompt(
            new SelectionPrompt<string>()
            .Title("Choose Architecture")
            .PageSize(10)
            .MoreChoicesText("[grey]Scroll for more...[/]")
            .AddChoices(data.Architectures)
            );

        // create a directory for the chosen architecture
        // NOTE: we also grab the path here so we can use it later.
        var Archdir = Directory.CreateDirectory(Path.Combine(DataDir, Arch)).FullName;

        // Check if the Release data we just grabbed is newer than the one that exists.
        // NOTE: we only do this if our chosen architecture hasn't been downloaded

        // OOF semaphores..
        bool NeedDownload = true;

        Log.Information("Reached Package download Stage");
        if (File.Exists(Path.Combine(Archdir, "Packages.gz")))
        {
            Log.Information("Checking for release.json");
            // we need to check the release since we have an existing package.gz

            string JSONstring = File.ReadAllText(Path.Combine(DataDir, "release.json"));
            ReleaseData? oldData = JsonSerializer.Deserialize<ReleaseData>(JSONstring);
            if (oldData is not null)
            {
                // if equal then our data is the newest available
                if (DateTime.Compare(oldData.Date, data.Date) == 0)
                {
                    Log.Information("Our packages.gz is up to date");
                    NeedDownload = false;
                }
            }
        }


        if (NeedDownload)
        {
            PackageFile gzFile =
                data.PackageFiles
                .Where(
                        file =>
                        file.filename.Contains(".gz") &&
                        file.filename.Contains(Arch)) // ensure we only fetch for the chosen architecture
                .First();
            if (gzFile is null)
            {
                throw new NullReferenceException("OOPS gzfile null");
            }
            string URL = "http://packages.microsoft.com/repos/edge/dists/stable/" + gzFile.filename;

            string filename = await AnsiConsole.Progress()
                .Columns(new ProgressColumn[]
                        {
                            new TaskDescriptionColumn(),
                            new ProgressBarColumn(),
                            new PercentageColumn(),
                            new RemainingTimeColumn(),
                            new SpinnerColumn(),
                        })
                .StartAsync<string>(async ctx =>
                        {
                            var task = ctx.AddTask(URL, new ProgressTaskSettings { AutoStart = false });

                            return await downloadFile(URL, Archdir, task);

                        });

            string JSONdata = JsonSerializer.Serialize<ReleaseData>(data);
            File.WriteAllText(Path.Combine(DataDir, "release.json"), JSONdata);
            if (!ValidateChecksum(filename, gzFile.Checksum))
            {
                File.Delete(filename);
                Environment.Exit(1);
            }
        }

        string PackagesFile = Path.Combine(Archdir, "Packages.gz");
        string PackagesString = GetPackagesString(PackagesFile);
        AnsiConsole.MarkupLineInterpolated($"Read {PackagesFile} see log for contents");
        Log.Debug("{packagesString}", PackagesString);

        List<Package> packages = new();
        StringBuilder sb = new();

        foreach (var line in PackagesString.Split('\n'))
        {
            if (line == "")
            {
                string PackageString = sb.ToString();
                sb.Clear(); // ensure we clear the StringBuilder when we are done with it.

                try
                {   // Just in case we somehow get a broken Package
                    Package p = new Package(PackageString);
                    packages.Add(p);
                }
                catch (Exception e)
                {
                    AnsiConsole.MarkupLine("[red]Error:[/] Could not create package from string");
                    AnsiConsole.MarkupLine("[yellow i]see log for more details[/]");
                    Log.Error("Could not create Package from passed string:\n{string}", PackageString);
                    Log.Error(e, "Exception thrown");
                }
            }
            sb.AppendLine(line);
        }

        /* INFO: This LINQ query allows sorting.
		 *	Pay special attention to the usage of the version comparer
		 */
        packages = packages
            .OrderBy(package => package.PackageName)
            .ThenByDescending(package => package.Version).ToList();
        // Print any packages we have
        var Variant = AnsiConsole.Prompt(
            new SelectionPrompt<string>()
            .Title("Choose variant")
            .PageSize(4)
            .AddChoices(new[] {
                    "stable",
                    "beta",
                    "dev",
                    "all"
                })
                );


        List<Package> VariantPackages = new();
        if (Variant == "" || Variant == "all")
        {
            VariantPackages = packages;
        }
        else
        {
            VariantPackages = packages
                    .Where(package =>
                        package.PackageName.Contains(Variant))
                    .ToList();
        }

        RenderPackagesTable(VariantPackages);


        var Package = AnsiConsole.Prompt(
            new SelectionPrompt<string>()
            .Title("Choose Package to Install")
            .PageSize(5)
            .AddChoices(VariantPackages.ConvertAll(pack => pack.PackageName).Distinct())
                );

        var ChosenPackages = packages
            .Where(package =>
                    package.PackageName == Package)
            .ToList();

        Package LatestVersion = ChosenPackages.OrderByDescending(pack => pack.Version).First();

        RenderPackageAsTable(LatestVersion);

        return 0;
    }

    static void RenderPackageAsTable(Package package)
    {
        Table Package = new Table()
            .Centered()
            .Border(TableBorder.Rounded)
            .HideHeaders()
            .Title("Package To Install");

        AnsiConsole.Live(Package)
            .AutoClear(false)
            .Start(context =>
            {
                Package.AddColumns("", "");
                context.Refresh();
                Thread.Sleep(250);

                Package.AddRow("[bold yellow]Package Name : [/]", $"{package.PackageName}");
                context.Refresh();
                Thread.Sleep(100);
                Package.AddRow("[bold yellow]Version : [/]", $"{package.Version.ToString()}");
                context.Refresh();
                Thread.Sleep(100);
                Package.AddRow("[bold yellow]Size : [/]", $"{package.Size.ToString()}B");
                context.Refresh();
                Thread.Sleep(100);
                Package.AddRow("[bold yellow]SHA256 : [/]", $"{package.SHA256}");
                context.Refresh();
                Thread.Sleep(100);
                Package.AddRow("[bold yellow]Filename : [/]", $"{package.Filename}");
                context.Refresh();
            });
    }

    static void RenderPackagesTable(List<Package> Packages)
    {
        Table PackageTable = new Table()
            .Centered()
            .Expand()
            .Border(TableBorder.Rounded)
            .Title("Packages");

        AnsiConsole.Live(PackageTable)
            .AutoClear(false)
            .Start(context =>
            {
                PackageTable
                .AddColumn("[bold]PackageName[/]")
                .AddColumn("[bold]Version[/]")
                .AddColumn("[bold]Size (bytes)[/]")
                .AddColumn("[bold]SHA256[/]")
                .AddColumn("[bold]Filename[/]");
                context.Refresh();
                Thread.Sleep(500);

                foreach (var pack in Packages)
                {
                    PackageTable.AddRow(FormatPackageName(pack.PackageName), $"[i blue]{pack.Version.ToString()}[/]", $"[grey]{pack.Size.ToString()}[/][b]B[/]", pack.SHA256, pack.Filename);
                    context.Refresh();
                    Thread.Sleep(100);
                }
            });

    }

    static string FormatPackageName(string name)
    {
        if (name.Contains("dev"))
        {
            return $"[red]{name}[/]";
        }
        if (name.Contains("beta"))
        {
            return $"[yellow]{name}[/]";
        }
        if (name.Contains("stable"))
        {
            return $"[green]{name}[/]";
        }
        return name;
    }

    static async Task<string> GetRelease()
    {
        string releaseURL = "http://packages.microsoft.com/repos/edge/dists/stable/Release";
        using HttpResponseMessage response = await _client.GetAsync(releaseURL);
        await Task.Delay(5000);
        response.EnsureSuccessStatusCode(); // WARNING: this can throw an exception, Please wrap in try/catch or rewrite function

        var body = await response.Content.ReadAsStringAsync();
        Log.Debug("{body}", body);
        return body;
    }

    static ReleaseData getReleaseData(string release)
    {
        return new ReleaseData(release);
    }

    static async Task<string> downloadFile(string URL, string DestinationDirectory)
    {

        Uri file = new Uri(URL);

        string fileLocation = Path.Combine(DestinationDirectory, file.Segments.Last());

        using HttpResponseMessage response = await _client.GetAsync(URL);
        response.EnsureSuccessStatusCode();

        await Task.Delay(2000);

        var fileData = response.Content.ReadAsStreamAsync();

        using var fileStream = new FileStream(fileLocation, FileMode.OpenOrCreate);
        await response.Content.CopyToAsync(fileStream);

        return fileLocation;
    }

    static async Task<string> downloadFile(string URL, string DestinationDirectory, ProgressTask task)
    {
        Uri file = new Uri(URL);
        string fileLocation = Path.Combine(DestinationDirectory, file.Segments.Last());

        using (HttpResponseMessage response = await _client.GetAsync(URL, HttpCompletionOption.ResponseHeadersRead))
        {
            response.EnsureSuccessStatusCode();


            task.MaxValue = response.Content.Headers.ContentLength ?? 0;
            task.StartTask();
            await Task.Delay(2000);

            AnsiConsole.MarkupLineInterpolated($"Starting download of [u]{URL}[/] ({task.MaxValue} Bytes)");

            using (var contentStream = await response.Content.ReadAsStreamAsync())
            using (var fileStream = File.Open(fileLocation, FileMode.OpenOrCreate))
            {
                var buffer = new byte[512];
                while (true)
                {
                    var read = await contentStream.ReadAsync(buffer, 0, buffer.Length);
                    await Task.Delay(500);
                    if (read == 0)
                    {
                        AnsiConsole.MarkupLineInterpolated($"Download of [u]{URL}[/] [green b]Complete![/]");
                        break;
                    }
                    task.Increment(read);

                    await fileStream.WriteAsync(buffer, 0, read);
                }
            }
        }

        return fileLocation;
    }

    static bool ValidateChecksum(string path, string checksum)
    {
        using (SHA256 mySHA256 = SHA256.Create())
        {
            using (FileStream fs = File.Open(path, FileMode.Open))
            {
                fs.Position = 0;

                byte[] hashValue = mySHA256.ComputeHash(fs);
                if (hashValue is null)
                {
                    throw new NullReferenceException("Hash be null??");
                }
                Log.Debug("Computed hash = {hash}", hashValue);
                byte[] storedHash = Convert.FromHexString(checksum);
                Log.Debug("Stored Hash = {hash}", storedHash);

                Log.Debug("Compare result = {result}", hashValue.SequenceEqual(storedHash));
                return (storedHash.SequenceEqual(hashValue));
            }
        }
    }

    static void RenderReleaseTable(ReleaseData data)
    {
        // Lets output this ReleaseData now
        Table ReleaseTable = new Table()
            .Centered()
            .Border(TableBorder.Rounded)
            .Expand()
            .Title("Release Data");

        AnsiConsole.Live(ReleaseTable)
            .AutoClear(false)
            .Start(context =>
                    {
                        ReleaseTable.AddColumn("[bold]Field[/]");
                        ReleaseTable.AddColumn("[bold]Value[/]");
                        context.Refresh();
                        Thread.Sleep(500);

                        ReleaseTable.AddRow("[bold yellow]Date:[/]", $"[blue]{data.Date:R}[/]");
                        context.Refresh();
                        Thread.Sleep(500);

                        Table archs = new Table()
                        .Centered()
                        .Border(TableBorder.None)
                        .HideFooters()
                        .HideHeaders()
                        .AddColumn(new TableColumn(Text.Empty));
                        ReleaseTable.AddRow(new Markup("[bold yellow]Architectures:[/]"), archs);
                        foreach (var arch in data.Architectures)
                        {
                            archs.AddRow(arch);
                            context.Refresh();
                            Thread.Sleep(250);
                        }

                        Table PackageFilesTable = new Table()
                            .Centered()
                            .Border(TableBorder.Square)
                            .BorderColor(Color.Red)
                            .AddColumn("[bold]Filename[/]")
                            .AddColumn("[bold]Checksum[/]")
                            .AddColumn("[bold]Size[/]");
                        ReleaseTable.AddRow(
                                new Markup("[bold yellow]Package Files:[/]"),
                                PackageFilesTable);
                        context.Refresh();
                        foreach (var PackageFile in data.PackageFiles)
                        {
                            PackageFilesTable.AddRow(PackageFile.filename, PackageFile.Checksum, PackageFile.size.ToString());
                            context.Refresh();
                            Thread.Sleep(250);
                        }
                    });
    }

    private static string GetPackagesString(string filepath)
    {
        using (var CompressedStream = File.Open(filepath, FileMode.Open))
        using (var decompressor = new GZipStream(CompressedStream, CompressionMode.Decompress))
        using (var streamReader = new StreamReader(decompressor))
        {
            return streamReader.ReadToEnd();
        }
    }

    /*TODO:
	  - Parse package to find latest version
	  - Check version
	  - Offer update
	  - Make SENSIBLE backup
	  - Do install
	  = if install fails revert backup
	  */
}