using System;
using System.Diagnostics;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
using AsyncAwaitBestPractices;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using StabilityMatrix.Avalonia.Views.Dialogs;
using StabilityMatrix.Core.Attributes;
using StabilityMatrix.Core.Helper;
using StabilityMatrix.Core.Models.Progress;
using StabilityMatrix.Core.Models.Update;
using StabilityMatrix.Core.Services;
using StabilityMatrix.Core.Updater;

namespace StabilityMatrix.Avalonia.ViewModels.Dialogs;

[View(typeof(UpdateDialog))]
public partial class UpdateViewModel : ContentDialogViewModelBase
{
    private readonly ISettingsManager settingsManager;
    private readonly IHttpClientFactory httpClientFactory;
    private readonly IUpdateHelper updateHelper;

    [ObservableProperty] private bool isUpdateAvailable;
    [ObservableProperty] private UpdateInfo? updateInfo;
    
    [ObservableProperty] private string? releaseNotes;
    [ObservableProperty] private string? updateText;
    [ObservableProperty] private int progressValue;
    [ObservableProperty] private bool showProgressBar;
    
    public UpdateViewModel(
        ISettingsManager settingsManager,
        IHttpClientFactory httpClientFactory, 
        IUpdateHelper updateHelper)
    {
        this.settingsManager = settingsManager;
        this.httpClientFactory = httpClientFactory;
        this.updateHelper = updateHelper;

        EventManager.Instance.UpdateAvailable += (_, info) =>
        {
            IsUpdateAvailable = true;
            UpdateInfo = info;
        };
        updateHelper.StartCheckingForUpdates().SafeFireAndForget();
    }
    
    public override async Task OnLoadedAsync()
    {
        if (UpdateInfo is null) return;
        
        UpdateText = $"Stability Matrix v{UpdateInfo.Version} is now available! You currently have v{Compat.AppVersion}. Would you like to update now?";
        
        var client = httpClientFactory.CreateClient();
        var response = await client.GetAsync(UpdateInfo.ChangelogUrl);
        if (response.IsSuccessStatusCode)
        {
            ReleaseNotes = await response.Content.ReadAsStringAsync();
            
            // Formatting for new changelog format
            // https://keepachangelog.com/en/1.1.0/
            if (UpdateInfo.ChangelogUrl.EndsWith(".md", StringComparison.OrdinalIgnoreCase))
            {
                // Skip until the first occurrence of "##"
                const string delimiter = "##";
                var startIndex = ReleaseNotes.IndexOf(delimiter, StringComparison.Ordinal);
                if (startIndex != -1)
                {
                    ReleaseNotes = ReleaseNotes[startIndex..];
                }
            }
        }
        else
        {
            ReleaseNotes = "## Unable to load release notes";
        }
    }

    [RelayCommand]
    private async Task InstallUpdate()
    {
        if (UpdateInfo == null)
        {
            return;
        }
        
        ShowProgressBar = true;
        UpdateText = $"Downloading update v{UpdateInfo.Version}...";
        await updateHelper.DownloadUpdate(UpdateInfo, new Progress<ProgressReport>(report =>
        {
            ProgressValue = Convert.ToInt32(report.Percentage);
        }));
        
        // On unix, we need to set the executable bit
        if (Compat.IsUnix)
        {
            File.SetUnixFileMode(UpdateHelper.ExecutablePath, // 0755
                UnixFileMode.UserRead | UnixFileMode.UserWrite |
                UnixFileMode.UserExecute | UnixFileMode.GroupRead |
                UnixFileMode.GroupExecute | UnixFileMode.OtherRead |
                UnixFileMode.OtherExecute);
        }
        
        UpdateText = "Update complete. Restarting Stability Matrix in 3 seconds...";
        await Task.Delay(1000);
        UpdateText = "Update complete. Restarting Stability Matrix in 2 seconds...";
        await Task.Delay(1000);
        UpdateText = "Update complete. Restarting Stability Matrix in 1 second...";
        await Task.Delay(1000);

        Process.Start(UpdateHelper.ExecutablePath);
        App.Shutdown();
    }
}