PowerShell: Add ไทย language pack

# =========================================================
# Script: Setup Thai Language + Grave Accent Toggle + Default User
# Version: 1.3.2 (Fixed Edition)
# =========================================================

# 0. Check Administrator rights
if (-not ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Write-Host "Please run this script as Administrator" -ForegroundColor Red
    pause
    exit
}

Write-Host "Checking Thai Language Pack..." -ForegroundColor Cyan

# 1. Check and install Language Pack
$thaiPacks = Get-WindowsCapability -Online | Where-Object { $_.Name -like "Language.Basic~~~th-TH*" }
if ($thaiPacks) {
    $thaiPack = $thaiPacks | Where-Object { $_.State -eq "Installed" } | Select-Object -First 1
    if (-not $thaiPack) { $thaiPack = $thaiPacks | Select-Object -First 1 }

    if ($thaiPack.State -eq "Installed") {
        Write-Host "Thai Language Pack already installed" -ForegroundColor Green
    } else {
        try {
            Write-Host "Installing Thai Language Pack (may take a while)..." -ForegroundColor Yellow
            Add-WindowsCapability -Online -Name $thaiPack.Name -ErrorAction Stop
            Write-Host "Installation successful" -ForegroundColor Green
        } catch {
            Write-Host "Installation failed, continuing..." -ForegroundColor Yellow
        }
    }
}

# 2. Setup for current user
Write-Host "Setting language order (EN-US primary + TH)..." -ForegroundColor Cyan
try {
    $LangList = New-WinUserLanguageList en-US
    $LangList.Add("th-TH")
    Set-WinUserLanguageList -LanguageList $LangList -Force -ErrorAction Stop
    Set-WinDefaultInputMethodOverride -InputTip "0409:00000409"
    Start-Sleep -Seconds 2
} catch {
    Write-Host "Failed to set language: $($_.Exception.Message)" -ForegroundColor Red
    pause
    exit
}

Write-Host "Setting Grave Accent key for language toggle..." -ForegroundColor Cyan

# Modern Toggle (Hotkey = 4 = Grave Accent)
$TogglePath = "HKCU:\Keyboard Layout\Toggle"
if (!(Test-Path $TogglePath)) { New-Item -Path $TogglePath -Force | Out-Null }
Set-ItemProperty -Path $TogglePath -Name "Hotkey" -Value "4" -Type String -Force

# Legacy Hotkey - Grave Accent alone (no modifier)
$LegacyPath = "HKCU:\Control Panel\Input Method\Hot Keys\00000000"
if (!(Test-Path $LegacyPath)) { New-Item -Path $LegacyPath -Force | Out-Null }
Set-ItemProperty -Path $LegacyPath -Name "Key Modifiers" -Value ([byte[]] @(0x00, 0xc0, 0x00, 0x00)) -Type Binary -Force
Set-ItemProperty -Path $LegacyPath -Name "Virtual Key" -Value ([byte[]] @(0xc0, 0x00, 0x00, 0x00)) -Type Binary -Force

Write-Host "Settings applied for current user" -ForegroundColor Green

# 3. Copy to Welcome Screen + New User
Write-Host "Copying settings to Welcome Screen..." -ForegroundColor Cyan
try {
    Copy-UserInternationalSettingsToSystem -WelcomeScreen -NewUser -ErrorAction Stop
    Write-Host "Copy successful" -ForegroundColor Green
} catch {
    Write-Host "Cannot copy to Welcome Screen (normal on some Win 11 builds)" -ForegroundColor Yellow
}

# 4. Setup for Default User (NTUSER.DAT)
Write-Host "Setting Grave Accent key for Default User..." -ForegroundColor Cyan

$DefaultUserPath = "C:\Users\Default\NTUSER.DAT"
$MountPath = "HKLM\DefaultUserTemp"

if (Test-Path $DefaultUserPath) {
    try {
        reg load $MountPath $DefaultUserPath 2>&1 | Out-Null
        if ($LASTEXITCODE -ne 0) { throw "Failed to load hive" }

        # Modern Toggle for Default User
        $DefTogglePath = "Registry::HKEY_LOCAL_MACHINE\DefaultUserTemp\Keyboard Layout\Toggle"
        if (!(Test-Path $DefTogglePath)) { New-Item -Path $DefTogglePath -Force | Out-Null }
        Set-ItemProperty -Path $DefTogglePath -Name "Hotkey" -Value "4" -Type String -Force

        # Legacy Hotkey for Default User
        $DefLegacyPath = "Registry::HKEY_LOCAL_MACHINE\DefaultUserTemp\Control Panel\Input Method\Hot Keys\00000000"
        if (!(Test-Path $DefLegacyPath)) { New-Item -Path $DefLegacyPath -Force | Out-Null }
        Set-ItemProperty -Path $DefLegacyPath -Name "Key Modifiers" -Value ([byte[]] @(0x00, 0xc0, 0x00, 0x00)) -Type Binary -Force
        Set-ItemProperty -Path $DefLegacyPath -Name "Virtual Key" -Value ([byte[]] @(0xc0, 0x00, 0x00, 0x00)) -Type Binary -Force

        Write-Host "Default User settings applied" -ForegroundColor Green
    }
    catch {
        Write-Host "Error setting Default User: $($_.Exception.Message)" -ForegroundColor Red
    }
    finally {
        # Unload Registry safely
        Set-Location C:\
        [gc]::Collect()
        [gc]::WaitForPendingFinalizers()
        Start-Sleep -Milliseconds 500

        $unloadRetry = 0
        while ($unloadRetry -lt 5) {
            reg unload $MountPath 2>$null | Out-Null
            if ($LASTEXITCODE -eq 0) {
                Write-Host "Unloaded Default User Registry." -ForegroundColor Gray
                break
            }
            $unloadRetry++
            Start-Sleep -Seconds 1
        }
        if ($unloadRetry -eq 5) {
            Write-Host "Cannot unload Registry, may need restart" -ForegroundColor Red
        }
    }
} else {
    Write-Host "Default User NTUSER.DAT not found" -ForegroundColor Red
}

# Summary
Write-Host "====================================================" -ForegroundColor Cyan
Write-Host "All operations completed!" -ForegroundColor Green
Write-Host "Recommend Sign out or Restart" -ForegroundColor Yellow
Write-Host "====================================================" -ForegroundColor Cyan

pause