powershell script to concatenate PDF into user selected order requires chocolatey and qpdf to be installed

concatenatepdf.ps1

# Check if qpdf is installed
$qpdfCheck = Get-Command qpdf -ErrorAction SilentlyContinue
if (-not $qpdfCheck) {
    Write-Host "QPDF is not installed. Please install it using: choco install qpdf"
    Write-Host "If you don't have chocolatey installed, visit https://chocolatey.org/install"
    exit
}

# Get all PDF files in current directory
$pdfFiles = Get-ChildItem -Path $PWD -Filter "*.pdf"

# Check if PDFs exist
if ($pdfFiles.Count -eq 0) {
    Write-Host "No PDF files found in current directory."
    exit
}

# Display numbered list of PDFs
Write-Host "`nAvailable PDF files:"
$pdfDict = @{}
for ($i = 1; $i -le $pdfFiles.Count; $i++) {
    $pdfDict[$i] = $pdfFiles[$i-1]
    Write-Host "$i $($pdfFiles[$i-1].Name)"
}

# Get user's desired order
$validInput = $false
while (-not $validInput) {
    $orderInput = Read-Host "`nEnter the numbers in desired order (comma-separated, e.g., 2,3,1)"
    $orderArray = $orderInput -split ',' | ForEach-Object { $_.Trim() }
    
    # Validate input
    $validInput = $true
    foreach ($num in $orderArray) {
        if (-not ([int]::TryParse($num, [ref]$null)) -or [int]$num -lt 1 -or [int]$num -gt $pdfFiles.Count) {
            Write-Host "Invalid input. Please use numbers between 1 and $($pdfFiles.Count)"
            $validInput = $false
            break
        }
    }
}

# Get output filename
$outputName = Read-Host "`nEnter name for combined PDF (without .pdf extension)"
$outputPath = Join-Path $PWD "$outputName.pdf"

try {
    # Build qpdf command
    $pdfPaths = $orderArray | ForEach-Object { $pdfDict[[int]$_].FullName }
    $qpdfArgs = @("--empty", "--pages") + $pdfPaths + @("--", $outputPath)
    
    # Execute qpdf
    Write-Host "`nCombining PDFs..."
    & qpdf $qpdfArgs

    if ($LASTEXITCODE -eq 0) {
        Write-Host "PDF combination complete!"
        Write-Host "Output file: $outputPath"
        
        # Get page count of resulting PDF
        $pageCountArgs = @("--show-npages", $outputPath)
        $totalPages = & qpdf $pageCountArgs
        Write-Host "Total pages: $totalPages"
    } else {
        Write-Host "Error combining PDFs."
    }

} catch {
    Write-Host "An error occurred: $_"
}