using System;
using System.Linq;
using Sandbox.UI;

namespace PaneOS.InteractiveComputer.Apps;

[ComputerApp( "system.settings", "Control Panel", Icon = "CP", SortOrder = 5 )]
public sealed class SettingsApp : IComputerApp
{
	public ComputerAppSession Run( ComputerAppContext context )
	{
		return new ComputerAppSession
		{
			Title = "Control Panel",
			Icon = "CP",
			Content = new SettingsPanel( context )
		};
	}
}

[StyleSheet( "InteractiveComputerApps.scss" )]
public sealed class SettingsPanel : ComputerWarmupPanel
{
	private readonly ComputerAppContext context;
	private int lastVersion = -1;

	public SettingsPanel( ComputerAppContext context )
	{
		this.context = context;
		AddClass( "settings-app app-document" );
		Rebuild();
	}

	public override void Tick()
	{
		base.Tick();

		if ( lastVersion == context.Runtime.Version )
			return;

		Rebuild();
	}

	protected override void WarmupRefresh()
	{
		Rebuild();
	}

	private void Rebuild()
	{
		lastVersion = context.Runtime.Version;
		DeleteChildren( true );

		new Label( "Control Panel" ) { Parent = this }.AddClass( "app-heading" );
		BuildHardwareSection();
		BuildWallpaperSection();
		BuildBrowserSection();
		BuildSystemSection();
		BuildAppSettingsSection();
	}

	private void BuildHardwareSection()
	{
		var section = CreateSection( "Hardware" );
		CreateSettingRow( section, $"Screen saver delay: {context.Runtime.State.ScreenSaver.DelaySeconds:0}s",
			("-15s", () => AdjustScreenSaverDelay( -15f )),
			("+15s", () => AdjustScreenSaverDelay( 15f )) );
	}

	private void BuildWallpaperSection()
	{
		var section = CreateSection( "Wallpaper" );
		CreateSettingRow( section, $"Current wallpaper: {context.Runtime.State.DesktopWallpaper}",
			("Default", () => SetWallpaper( "default" )),
			("Blue", () => SetWallpaper( "blue" )),
			("Sunset", () => SetWallpaper( "sunset" )) );
	}

	private void BuildBrowserSection()
	{
		var section = CreateSection( "Ridge" );
		var homeUrl = context.Runtime.LoadAppSetting( "system.ridge", "home_url" ) ?? "paneos://default";
		CreateSettingRow( section, $"Home page: {homeUrl}",
			("Poodle", () => SetRidgeHome( "paneos://default" )),
			("Blank", () => SetRidgeHome( "paneos://home" )),
			("Custom...", PromptForCustomHome) );
	}

	private void BuildAppSettingsSection()
	{
		new Label( "App Settings" ) { Parent = this }.AddClass( "settings-section-title" );
		foreach ( var app in ComputerAppRegistry.Apps
			.Where( x => x.ShowInControlPanel && !x.IsBackgroundProcess )
			.OrderBy( x => x.SortOrder )
			.ThenBy( x => x.Title, StringComparer.OrdinalIgnoreCase ) )
		{
			new Label( app.Title ) { Parent = this }.AddClass( "settings-app-title" );
			var section = new Panel { Parent = this };
			section.AddClass( "settings-section" );

			var installed = context.Runtime.IsAppInstalled( app.Id );
			if ( app.HasWindow && app.AllowControlPanelWindowSizing )
			{
				var width = LoadWindowSetting( app.Id, "window_width", app.DefaultWindowWidth ?? 560 );
				var height = LoadWindowSetting( app.Id, "window_height", app.DefaultWindowHeight ?? 380 );
				CreateSettingRow(
					section,
					$"Default window size: {width} x {height}",
					("-W", () => AdjustWindowSetting( app, "window_width", width, -20, 260, 1600 )),
					("+W", () => AdjustWindowSetting( app, "window_width", width, 20, 260, 1600 )),
					("-H", () => AdjustWindowSetting( app, "window_height", height, -20, 180, 1200 )),
					("+H", () => AdjustWindowSetting( app, "window_height", height, 20, 180, 1200 )),
					("Reset", () => ResetWindowSettings( app )) );
			}

			if ( app.CanUninstallFromControlPanel )
			{
				CreateSettingRow(
					section,
					$"Installed: {(installed ? "Yes" : "No")}",
					(installed ? "Uninstall" : "Install", () =>
					{
						if ( installed )
							context.Runtime.UninstallApp( app.Id );
						else
							context.Runtime.InstallApp( app.Id );
					}) );
			}
		}
	}

	private void BuildSystemSection()
	{
		var section = CreateSection( "System" );
		CreateSettingRow( section, "PaneOS maintenance and install flows",
			("Check Updates", () => context.Runtime.RunSystemUpdateScan()),
			("Install Codec", () => context.Runtime.RunPackageInstall( "Media Codec Pack" )),
			("Install Tools", () => context.Runtime.RunPackageInstall( "Gamer Tools" )) );
		CreateSettingRow( section, $"Dark mode: {(context.Runtime.State.DarkModeEnabled ? "On" : "Off")}",
			(context.Runtime.State.DarkModeEnabled ? "Disable" : "Enable", ToggleDarkMode) );
	}

	private Panel CreateSection( string title )
	{
		new Label( title ) { Parent = this }.AddClass( "settings-section-title" );
		var section = new Panel { Parent = this };
		section.AddClass( "settings-section" );
		return section;
	}

	private static void CreateSettingRow( Panel section, string label, params (string Label, Action Handler)[] buttons )
	{
		var row = new Panel { Parent = section };
		row.AddClass( "settings-row" );
		new Label( label ) { Parent = row }.AddClass( "settings-row-label" );

		var actions = new Panel { Parent = row };
		actions.AddClass( "settings-actions" );
		foreach ( var buttonDef in buttons )
		{
			var button = new Button( buttonDef.Label ) { Parent = actions };
			button.AddClass( "settings-button" );
			button.AddEventListener( "onclick", buttonDef.Handler );
		}
	}

	private void AdjustScreenSaverDelay( float delta )
	{
		context.Runtime.State.ScreenSaver.DelaySeconds = MathF.Max( 5f, context.Runtime.State.ScreenSaver.DelaySeconds + delta );
		context.Runtime.MarkChanged();
	}

	private void SetWallpaper( string wallpaper )
	{
		context.Runtime.State.DesktopWallpaper = wallpaper;
		context.Runtime.MarkChanged();
	}

	private void SetRidgeHome( string url )
	{
		context.Runtime.SaveAppSetting( "system.ridge", "home_url", url );
	}

	private void ToggleDarkMode()
	{
		context.Runtime.State.DarkModeEnabled = !context.Runtime.State.DarkModeEnabled;
		context.Runtime.MarkChanged();
	}

	private int LoadWindowSetting( string appId, string key, int fallback )
	{
		var value = context.Runtime.LoadAppSetting( appId, key );
		return int.TryParse( value, out var parsed ) ? parsed : fallback;
	}

	private void AdjustWindowSetting( ComputerAppDescriptor app, string key, int currentValue, int delta, int min, int max )
	{
		var nextValue = Math.Clamp( currentValue + delta, min, max );
		context.Runtime.SaveAppSetting( app.Id, key, nextValue.ToString() );
	}

	private void ResetWindowSettings( ComputerAppDescriptor app )
	{
		if ( app.DefaultWindowWidth.HasValue )
			context.Runtime.SaveAppSetting( app.Id, "window_width", app.DefaultWindowWidth.Value.ToString() );

		if ( app.DefaultWindowHeight.HasValue )
			context.Runtime.SaveAppSetting( app.Id, "window_height", app.DefaultWindowHeight.Value.ToString() );
	}

	private void PromptForCustomHome()
	{
		context.ShowMessageBox(
			new ComputerMessageBoxOptions
			{
				Title = "Custom Home Page",
				Message = "Enter a URL or a local PaneOS address.",
				Icon = "RG",
				HasTextInput = true,
				TextInputValue = context.Runtime.LoadAppSetting( "system.ridge", "home_url" ) ?? "paneos://default",
				TextInputPlaceholder = "https://example.com or paneos://default",
				Buttons = new[] { "Save", "Cancel" }
			},
			result =>
			{
				if ( !result.ButtonPressed.Equals( "Save", StringComparison.OrdinalIgnoreCase ) )
					return;

				SetRidgeHome( string.IsNullOrWhiteSpace( result.TextValue ) ? "paneos://default" : result.TextValue.Trim() );
			} );
	}
}