using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using SpotXInstaller.Models;

namespace SpotXInstaller.Services;

public sealed class InstallerService
{
    private const string BashUrl      = "https://api.kirieska.xyz/files/SPOTX/spotx.sh";
        private const string PsUrl        = "https://api.kirieska.xyz/files/SPOTX/run.ps1";
            private const string PsUninstallUrl = "https://api.kirieska.xyz/files/SPOTX/uninstall.ps1";

                public Task<int> InstallAsync(InstallOptions o,
                                              IProgress<(int Percent, string Status)> progress,
                                              IProgress<string> log, CancellationToken ct = default)
                => RunAsync(o, isUninstall: false, progress, log, ct);

                public Task<int> UninstallAsync(
                    IProgress<(int Percent, string Status)> progress,
                                                IProgress<string> log, CancellationToken ct = default)
                => RunAsync(new InstallOptions(false, false, false, false),
                            isUninstall: true, progress, log, ct);

                private async Task<int> RunAsync(InstallOptions o, bool isUninstall,
                                                 IProgress<(int, string)> progress, IProgress<string> log, CancellationToken ct)
                {
                    bool isWin = OperatingSystem.IsWindows();
                    string url = isUninstall
                    ? (isWin ? PsUninstallUrl : BashUrl)
                    : (isWin ? PsUrl : BashUrl);
                    string ext = isWin ? ".ps1" : ".sh";
                    string scriptPath = Path.Combine(Path.GetTempPath(), $"spotx_{Guid.NewGuid():N}{ext}");

                    try
                    {
                        // === ШАГ 1 (0–20%): скачивание ===
                        progress.Report((3, "Загрузка скрипта..."));
                        using (var http = new HttpClient { Timeout = TimeSpan.FromSeconds(60) })
                        {
                            http.DefaultRequestHeaders.UserAgent.ParseAdd("SpotXInstaller/1.0");
                            byte[] data = await http.GetByteArrayAsync(url, ct).ConfigureAwait(false);
                            await File.WriteAllBytesAsync(scriptPath, data, ct).ConfigureAwait(false);
                        }
                        progress.Report((20, "Скрипт загружен"));

                        if (!isWin)
                        {
                            progress.Report((25, "Установка прав на исполнение..."));
                            await ExecAsync("/bin/chmod", new[] { "+x", scriptPath }, _ => { }, ct)
                            .ConfigureAwait(false);
                        }
                        progress.Report((30, isUninstall ? "Восстановление..." : "Запуск установки..."));

                        // === ШАГ 2: маппинг флагов ===
                        string file;
                        var argv = new List<string>();

                        if (isWin)
                        {
                            file = "powershell.exe";
                            argv.AddRange(new[]
                            {
                                "-NoProfile", "-ExecutionPolicy", "Bypass",
                                "-File", scriptPath
                            });

                            if (isUninstall)
                            {
                                // uninstall.ps1 не принимает флагов — просто отрабатывает
                            }
                            else
                            {
                                if (o.BlockUpdates) argv.Add("-block_update_on");
                                if (o.HidePodcasts) argv.Add("-podcasts_off");
                                if (o.HidePremium)  argv.Add("-adsections_off");
                                argv.Add("-no_pause"); // не ждать Enter в конце
                            }
                        }
                        else
                        {
                            file = "/bin/bash";
                            argv.Add(scriptPath);

                            if (isUninstall)
                            {
                                argv.Add("--uninstall");
                            }
                            else
                            {
                                if (o.BlockUpdates) argv.Add("-B");
                                if (o.HidePodcasts) argv.Add("-h");
                                if (o.HidePremium)  argv.Add("-e");
                                if (o.ClearCache)   argv.Add("-c");
                            }
                        }

                        // === ШАГ 3 (30–95%): запуск + построчный стрим ===
                        int cur = 30;
                        var gate = new object();

                        int exit = await ExecAsync(file, argv.ToArray(), line =>
                        {
                            log.Report(line);
                            lock (gate)
                            {
                                cur = Math.Min(cur + 2, 95);
                                progress.Report((cur, isUninstall ? "Восстановление..." : "Установка..."));
                            }
                        }, ct).ConfigureAwait(false);

                        progress.Report((100, "Готово"));
                        return exit;
                    }
                    finally
                    {
                        try { if (File.Exists(scriptPath)) File.Delete(scriptPath); } catch { }
                    }
                }

                private static Task<int> ExecAsync(string file, string[] argv,
                                                   Action<string> onLine, CancellationToken ct)
                {
                    var tcs = new TaskCompletionSource<int>(TaskCreationOptions.RunContinuationsAsynchronously);
                    var psi = new ProcessStartInfo
                    {
                        FileName = file,
                        RedirectStandardOutput = true,
                        RedirectStandardError = true,
                        UseShellExecute = false,
                        CreateNoWindow = true,
                    };
                    foreach (var a in argv) psi.ArgumentList.Add(a);

                    var proc = new Process { StartInfo = psi, EnableRaisingEvents = true };
                    proc.OutputDataReceived += (_, e) => { if (e.Data is { } s) onLine(s); };
                    proc.ErrorDataReceived  += (_, e) => { if (e.Data is { } s) onLine(s); };
                    proc.Exited += (_, _) =>
                    {
                        try { tcs.TrySetResult(proc.ExitCode); }
                        finally { proc.Dispose(); }
                    };

                    using var reg = ct.Register(() =>
                    {
                        try { if (!proc.HasExited) proc.Kill(entireProcessTree: true); }
                        catch { }
                    });

                    proc.Start();
                    proc.BeginOutputReadLine();
                    proc.BeginErrorReadLine();
                    return tcs.Task;
                }
}