mcp-windows/src/tools/theme.ts

/* Copyright (C) 2026 Moko Consulting <hello@mokoconsulting.tech>
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * Tools: windows_theme_get (#52), windows_theme_set (#53),
 *        windows_focus_mode (#55), windows_default_apps (#56)
 */

import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { z } from 'zod';
import { runPowerShell } from '../shell.js';

export function registerThemeTools(server: McpServer): void {
	server.tool(
		'windows_theme_get',
		'Get current Windows theme: dark/light mode, accent color, wallpaper, transparency, taskbar alignment.',
		{},
		async () => {
			const ps = `
$personalize = 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize'
$accent = 'HKCU:\\Software\\Microsoft\\Windows\\DWM'
$taskbar = 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced'
$wallpaper = (Get-ItemProperty -Path 'HKCU:\\Control Panel\\Desktop' -Name Wallpaper -ErrorAction SilentlyContinue).Wallpaper

$appsDark = (Get-ItemProperty -Path $personalize -Name AppsUseLightTheme -ErrorAction SilentlyContinue).AppsUseLightTheme -eq 0
$systemDark = (Get-ItemProperty -Path $personalize -Name SystemUsesLightTheme -ErrorAction SilentlyContinue).SystemUsesLightTheme -eq 0
$transparency = (Get-ItemProperty -Path $personalize -Name EnableTransparency -ErrorAction SilentlyContinue).EnableTransparency -eq 1
$accentColor = (Get-ItemProperty -Path $accent -Name AccentColor -ErrorAction SilentlyContinue).AccentColor
$taskbarAlign = (Get-ItemProperty -Path $taskbar -Name TaskbarAl -ErrorAction SilentlyContinue).TaskbarAl

$accentHex = if ($accentColor) {
  $b = ($accentColor -band 0xFF0000) -shr 16
  $g = ($accentColor -band 0x00FF00) -shr 8
  $r = ($accentColor -band 0x0000FF)
  '#{0:X2}{1:X2}{2:X2}' -f $r, $g, $b
} else { 'Unknown' }

[PSCustomObject]@{
  AppsDarkMode = $appsDark
  SystemDarkMode = $systemDark
  AccentColor = $accentHex
  Transparency = $transparency
  Wallpaper = $wallpaper
  TaskbarAlignment = if ($taskbarAlign -eq 0) { 'Left' } else { 'Center' }
} | ConvertTo-Json -Compress`;

			const result = await runPowerShell(ps, { timeout: 10000 });
			if (result.exitCode !== 0) {
				return { content: [{ type: 'text', text: `Error: ${result.stderr}` }], isError: true };
			}

			const t = JSON.parse(result.stdout);
			return {
				content: [{
					type: 'text',
					text: [
						`Dark mode: Apps=${t.AppsDarkMode}, System=${t.SystemDarkMode}`,
						`Accent color: ${t.AccentColor}`,
						`Transparency: ${t.Transparency ? 'On' : 'Off'}`,
						`Taskbar: ${t.TaskbarAlignment}`,
						`Wallpaper: ${t.Wallpaper || '(none)'}`,
					].join('\n'),
				}],
			};
		},
	);

	server.tool(
		'windows_theme_set',
		'Set dark/light mode, accent color, wallpaper, transparency, or taskbar alignment.',
		{
			dark_mode: z.enum(['on', 'off']).optional().describe('Set dark mode for apps and system'),
			wallpaper: z.string().optional().describe('Wallpaper file path'),
			wallpaper_fit: z.enum(['fill', 'fit', 'stretch', 'tile', 'center', 'span']).optional().describe('Wallpaper fit mode'),
			transparency: z.enum(['on', 'off']).optional().describe('Transparency effects'),
			taskbar_align: z.enum(['left', 'center']).optional().describe('Taskbar alignment'),
		},
		async ({ dark_mode, wallpaper, wallpaper_fit, transparency, taskbar_align }) => {
			const commands: string[] = [];

			if (dark_mode) {
				const val = dark_mode === 'on' ? 0 : 1;
				commands.push(`Set-ItemProperty -Path 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize' -Name AppsUseLightTheme -Value ${val}`);
				commands.push(`Set-ItemProperty -Path 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize' -Name SystemUsesLightTheme -Value ${val}`);
				commands.push(`"Dark mode: ${dark_mode}"`);
			}

			if (transparency) {
				const val = transparency === 'on' ? 1 : 0;
				commands.push(`Set-ItemProperty -Path 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize' -Name EnableTransparency -Value ${val}`);
				commands.push(`"Transparency: ${transparency}"`);
			}

			if (taskbar_align) {
				const val = taskbar_align === 'left' ? 0 : 1;
				commands.push(`Set-ItemProperty -Path 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\Advanced' -Name TaskbarAl -Value ${val}`);
				commands.push(`"Taskbar: ${taskbar_align}"`);
			}

			if (wallpaper) {
				const fitMap: Record<string, string> = { fill: '10', fit: '6', stretch: '2', tile: '0', center: '0', span: '22' };
				const fit = wallpaper_fit || 'fill';
				commands.push(`
Set-ItemProperty -Path 'HKCU:\\Control Panel\\Desktop' -Name WallpaperStyle -Value '${fitMap[fit]}'
Set-ItemProperty -Path 'HKCU:\\Control Panel\\Desktop' -Name TileWallpaper -Value '${fit === 'tile' ? '1' : '0'}'
Add-Type -TypeDefinition 'using System.Runtime.InteropServices; public class Wallpaper { [DllImport("user32.dll", CharSet=CharSet.Auto)] public static extern int SystemParametersInfo(int uAction, int uParam, string lpvParam, int fuWinIni); }'
[Wallpaper]::SystemParametersInfo(0x0014, 0, '${wallpaper.replace(/'/g, "''")}', 0x01 -bor 0x02) | Out-Null
"Wallpaper set: ${wallpaper} (${fit})"
`);
			}

			if (commands.length === 0) {
				return { content: [{ type: 'text', text: 'No changes specified.' }], isError: true };
			}

			const result = await runPowerShell(commands.join('\n'), { timeout: 15000 });
			return {
				content: [{ type: 'text', text: result.stdout || result.stderr }],
				isError: result.exitCode !== 0,
			};
		},
	);

	server.tool(
		'windows_focus_mode',
		'Get or set Windows Focus Assist / Do Not Disturb mode.',
		{
			action: z.enum(['get', 'priority', 'alarms', 'off']).default('get').describe('Get status or set mode'),
		},
		async ({ action }) => {
			if (action === 'get') {
				const ps = `
$regPath = 'HKCU:\\Software\\Microsoft\\Windows\\CurrentVersion\\CloudStore\\Store\\DefaultAccount\\Current\\default$windows.data.notifications.quiethourssettings\\windows.data.notifications.quiethourssettings'
$mode = 'Unknown'
try {
  $val = (Get-ItemProperty -Path $regPath -ErrorAction Stop).Data
  if ($val) {
    # The focus assist state is encoded in the binary blob
    $mode = 'Check via Settings app (binary registry format)'
  }
} catch { $mode = 'Off (or unable to read)' }
"Focus Assist: $mode"`;
				const result = await runPowerShell(ps, { timeout: 10000 });
				return { content: [{ type: 'text', text: result.stdout || result.stderr }] };
			}

			// Setting focus assist requires ms-settings URI
			const ps = `Start-Process 'ms-settings:quiethours'; "Opened Focus Assist settings. Mode requested: ${action}"`;
			const result = await runPowerShell(ps, { timeout: 10000 });
			return { content: [{ type: 'text', text: result.stdout || result.stderr }] };
		},
	);

	server.tool(
		'windows_default_apps',
		'Get default applications or open the default apps settings page.',
		{
			action: z.enum(['get', 'open_settings']).default('get').describe('Get defaults or open settings'),
			extension: z.string().optional().describe('File extension to check (e.g. ".pdf")'),
		},
		async ({ action, extension }) => {
			if (action === 'open_settings') {
				await runPowerShell('Start-Process "ms-settings:defaultapps"');
				return { content: [{ type: 'text', text: 'Opened Default Apps settings.' }] };
			}

			if (extension) {
				const ps = `
$assoc = cmd /c assoc ${extension} 2>$null
$ftype = if ($assoc) { $type = ($assoc -split '=')[1]; cmd /c ftype $type 2>$null } else { $null }
[PSCustomObject]@{
  Extension = '${extension}'
  FileType = if ($assoc) { ($assoc -split '=')[1] } else { 'Not associated' }
  OpensWith = if ($ftype) { ($ftype -split '=')[1] } else { 'Unknown' }
} | ConvertTo-Json -Compress`;
				const result = await runPowerShell(ps, { timeout: 10000 });
				if (result.exitCode !== 0) {
					return { content: [{ type: 'text', text: `Error: ${result.stderr}` }], isError: true };
				}
				const info = JSON.parse(result.stdout);
				return { content: [{ type: 'text', text: `${info.Extension} -> ${info.FileType} -> ${info.OpensWith}` }] };
			}

			// List common defaults
			const ps = `
$defaults = @('.html','.pdf','.txt','.jpg','.png','.mp3','.mp4','.zip') | ForEach-Object {
  $ext = $_
  $assoc = cmd /c assoc $ext 2>$null
  $type = if ($assoc) { ($assoc -split '=')[1] } else { 'N/A' }
  [PSCustomObject]@{ Extension = $ext; FileType = $type }
}
$defaults | ConvertTo-Json -Depth 3 -Compress`;

			const result = await runPowerShell(ps, { timeout: 15000 });
			if (result.exitCode !== 0) {
				return { content: [{ type: 'text', text: `Error: ${result.stderr}` }], isError: true };
			}

			const defaults = Array.isArray(JSON.parse(result.stdout)) ? JSON.parse(result.stdout) : [JSON.parse(result.stdout)];
			const lines = defaults.map((d: { Extension: string; FileType: string }) =>
				`  ${d.Extension.padEnd(8)}  ${d.FileType}`,
			);
			return { content: [{ type: 'text', text: `Default file associations:\n${lines.join('\n')}` }] };
		},
	);
}