<#
.SYNOPSIS
    Ensure WiX Toolset 3.14 (build 3141) is installed and ready to use.

.DESCRIPTION
    - Skips installation if the toolset is already installed (unless -Force is used).
    - Otherwise downloads the official installer and binaries, verifies SHA-256, installs silently,
      and copies wix.targets into the installation directory.
.PARAMETER Force
    Forces reinstallation even if the toolset is already detected.
.PARAMETER InstallDir
    The target installation path. Default is 'C:\Program Files (x86)\WiX Toolset v3.14'.
.EXAMPLE
    .\EnsureWix.ps1          # Ensure WiX is installed
    .\EnsureWix.ps1 -Force   # Force reinstall
#>
[CmdletBinding()]
param(
    [switch]$Force,
    [string]$InstallDir = 'C:\Program Files (x86)\WiX Toolset v3.14'
)

$ErrorActionPreference = 'Stop'
$ProgressPreference    = 'SilentlyContinue'

# Download URLs and expected SHA-256 hashes
$WixDownloadUrl         = 'https://github.com/wixtoolset/wix3/releases/download/wix3141rtm/wix314.exe'
$WixBinariesDownloadUrl = 'https://github.com/wixtoolset/wix3/releases/download/wix3141rtm/wix314-binaries.zip'
$InstallerHashExpected  = '6BF6D03D6923D9EF827AE1D943B90B42B8EBB1B0F68EF6D55F868FA34C738A29'
$BinariesHashExpected   = '6AC824E1642D6F7277D0ED7EA09411A508F6116BA6FAE0AA5F2C7DAA2FF43D31'

# Check if WiX is already installed
$candlePath = Join-Path $InstallDir 'bin\candle.exe'
if (-not $Force -and (Test-Path $candlePath)) {
    Write-Host "WiX Toolset is already installed at `"$InstallDir`". Skipping installation."
    return
}

# Temp file paths
$tmpDir      = [IO.Path]::GetTempPath()
$installer   = Join-Path $tmpDir 'wix314.exe'
$binariesZip = Join-Path $tmpDir 'wix314-binaries.zip'

# Download installer and binaries
Write-Host 'Downloading WiX installer...'
Invoke-WebRequest -Uri $WixDownloadUrl         -OutFile $installer    -UseBasicParsing
Write-Host 'Downloading WiX binaries...'
Invoke-WebRequest -Uri $WixBinariesDownloadUrl -OutFile $binariesZip  -UseBasicParsing

# Verify SHA-256 hashes
Write-Host 'Verifying installer hash...'
if ((Get-FileHash -Algorithm SHA256 $installer).Hash -ne $InstallerHashExpected) {
    throw 'wix314.exe SHA256 hash mismatch'
}
Write-Host 'Verifying binaries hash...'
if ((Get-FileHash -Algorithm SHA256 $binariesZip).Hash -ne $BinariesHashExpected) {
    throw 'wix314-binaries.zip SHA256 hash mismatch'
}

# Perform silent installation
Write-Host 'Installing WiX Toolset silently...'
Start-Process -FilePath $installer -ArgumentList '/install','/quiet' -Wait

# Extract binaries and copy wix.targets
$expandDir = Join-Path $tmpDir 'wix-binaries'
if (Test-Path $expandDir) { Remove-Item $expandDir -Recurse -Force }
Expand-Archive -Path $binariesZip -DestinationPath $expandDir -Force
Copy-Item -Path (Join-Path $expandDir 'wix.targets') `
          -Destination (Join-Path $InstallDir  'wix.targets') -Force

Write-Host "WiX Toolset has been successfully installed at: $InstallDir"