using ChrisKaczor.Wpf.Windows;
using ChrisKaczor.Wpf.Windows.FloatingStatusWindow;
using ProcessCpuUsageStatusWindow.Properties;
using ProcessCpuUsageStatusWindow.SettingsWindow;
using Serilog;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Threading;

namespace ProcessCpuUsageStatusWindow;

internal class WindowSource : IWindowSource, IDisposable
{
    private readonly FloatingStatusWindow _floatingStatusWindow;
    private readonly Dispatcher _dispatcher;
    private readonly ProcessCpuUsageWatcher _processCpuUsageWatcher;

    internal WindowSource()
    {
        _floatingStatusWindow = new FloatingStatusWindow(this);
        _floatingStatusWindow.SetText(Resources.Loading);

        _dispatcher = Dispatcher.CurrentDispatcher;

        _processCpuUsageWatcher = new ProcessCpuUsageWatcher();

        Task.Factory.StartNew(UpdateApp).ContinueWith(task => Start(task.Result.Result));
    }

    private async Task<bool> UpdateApp()
    {
        try
        {
            if (!UpdateCheck.IsInstalled)
                return false;

            if (!Settings.Default.CheckVersionAtStartup)
                return false;

            Log.Logger.Information("Checking for update");

            await _dispatcher.InvokeAsync(() => _floatingStatusWindow.SetText(Resources.CheckingForUpdate));

            var newVersion = await UpdateCheck.UpdateManager.CheckForUpdatesAsync();

            if (newVersion == null)
                return false;

            Log.Logger.Information("Downloading update");

            await _dispatcher.InvokeAsync(() => _floatingStatusWindow.SetText(Resources.DownloadingUpdate));

            await UpdateCheck.UpdateManager.DownloadUpdatesAsync(newVersion);

            Log.Logger.Information("Installing update");

            await _dispatcher.InvokeAsync(() => _floatingStatusWindow.SetText(Resources.InstallingUpdate));

            UpdateCheck.UpdateManager.ApplyUpdatesAndRestart(newVersion);
        }
        catch (Exception e)
        {
            Log.Logger.Error(e, nameof(UpdateApp));
        }

        return true;
    }

    private void Start(bool hasUpdate)
    {
        Log.Logger.Information("Start: hasUpdate={HasUpdate}", hasUpdate);

        if (hasUpdate)
            return;

        Log.Logger.Information("Load");

        Load();
    }

    private void Load()
    {
        Task.Factory.StartNew(() => _processCpuUsageWatcher.Initialize(Settings.Default.UpdateInterval, UpdateDisplay, _dispatcher));
    }

    private static void Save()
    {
    }

    public void Dispose()
    {
        _processCpuUsageWatcher.Terminate();

        _floatingStatusWindow.Save();
        _floatingStatusWindow.Dispose();
    }

    public Guid Id => Guid.Parse("D2DFC480-891F-4C66-B344-69D420561A11");

    public string Name => Resources.ApplicationName;

    public System.Drawing.Icon Icon => Resources.ApplicationIcon;

    public bool HasSettingsMenu => true;

    public bool HasAboutMenu => false;

    public void ShowAbout()
    {
    }

    public void ShowSettings()
    {
        var categoryPanels = new List<CategoryPanelBase>
        {
            new GeneralSettingsPanel(),
            new UpdateSettingsPanel(),
            new AboutSettingsPanel()
        };

        var settingsWindow = new CategoryWindow(categoryPanels, Resources.SettingsTitle, Resources.CloseButtonText);

        settingsWindow.ShowDialog();

        Save();
    }

    public bool HasRefreshMenu => false;

    public void Refresh()
    {
        UpdateDisplay(_processCpuUsageWatcher.CurrentProcessList);
    }

    public string WindowSettings
    {
        get => Settings.Default.WindowSettings;
        set
        {
            Settings.Default.WindowSettings = value;
            Settings.Default.Save();
        }
    }

    private static class PredefinedProcessName
    {
        public const string Total = "_Total";
        public const string Idle = "Idle";
        public const string IdleWithProcessId = "Idle:0";
    }

    private void UpdateDisplay(Dictionary<string, ProcessCpuUsage> currentProcessList)
    {
        // Filter the process list to valid ones and exclude the idle and total values
        var validProcessList = currentProcessList.Values.Where(process =>
            process.UsageValid && process.ProcessName != PredefinedProcessName.Total &&
            process.ProcessName != (_processCpuUsageWatcher.IsV2 ? PredefinedProcessName.IdleWithProcessId : PredefinedProcessName.Idle)).ToList();

        // Calculate the total usage by adding up all the processes we know about
        var totalUsage = validProcessList.Sum(process => process.PercentUsage);

        // Sort the process list by usage and take only the top few
        var sortedProcessList = validProcessList.OrderByDescending(process => process.PercentUsage).Take(Settings.Default.ProcessCount);

        // Create a new string builder
        var stringBuilder = new StringBuilder();

        // Loop over all processes in the sorted list
        foreach (var processCpuUsage in sortedProcessList)
        {
            // Move to the next line if it isn't the first line
            if (stringBuilder.Length != 0)
                stringBuilder.AppendLine();

            if (_processCpuUsageWatcher.IsV2)
            {
                // Split the process name from the process ID
                var colonPosition = processCpuUsage.ProcessName.LastIndexOf(':');

                var processName = processCpuUsage.ProcessName[..colonPosition];
                var processId = processCpuUsage.ProcessName[(colonPosition + 1)..];

                var formatString = Settings.Default.ShowProcessId ? Resources.ProcessLineWithProcessId : Resources.ProcessLine;

                // Format the process information into a string to display
                stringBuilder.AppendFormat(formatString, processName, processCpuUsage.PercentUsage, processId);
            }
            else
            {
                // Format the process information into a string to display
                stringBuilder.AppendFormat(Resources.ProcessLine, processCpuUsage.ProcessName, processCpuUsage.PercentUsage);
            }
        }

        // Add the footer line (if any)
        if (Resources.FooterLine.Length > 0)
        {
            stringBuilder.AppendLine();
            stringBuilder.AppendLine();
            stringBuilder.AppendFormat(Resources.FooterLine, totalUsage);
        }

        // Update the window with the text
        _floatingStatusWindow.SetText(stringBuilder.ToString());
    }
}