# DOCX to PDF after Markdown generation
# Copyright Emanuele Ruffaldi MMI 2024
# License: MIT
#
# Usage:
#      script INPUT.DOCX
#
# Output: INPUT.PDF
#
# Requirements
# - remove existing PDF
# - FAIL if DOCX missing
# - FAIL if PDF cannot be generated
# - FAIL if there are missing references
# - launches Word unattended, hidden and timeout of 60s
# - regenrates fields and toc
# - export PDF without comments and changes
# - steps: open, update fields and toc, check references, save, export pdf

param (
    [string]$in
)

# Ensure the input file path is absolute
$inputFilePath=$in
$inputFilePath = [System.IO.Path]::GetFullPath($inputFilePath)

if (-not (Test-Path $inputFilePath)) {
    Write-Error "The specified input file does not exist: $inputFilePath"
    exit 1
}

# Generate the output file path by changing the extension to .pdf
$outputFilePath = [System.IO.Path]::ChangeExtension($inputFilePath, ".pdf")

# Remove if exists
if ((Test-Path $outputFilePath)) {
    Remove-Item $outputFilePath
}

# Timeout
$timeoutSeconds = 60

$ProcessWordDocument = {
    param ($inputFilePath, $outputFilePath)

    Write-Output "ProcessWordDocument"

    # Create a new Word application object
    $word = New-Object -ComObject Word.Application
    $word.Visible = $false  # Keep Word application hidden
    $word.DisplayAlerts = [Microsoft.Office.Interop.Word.WdAlertLevel]::wdAlertsNone  # Disable alerts

    try {
        # Open the document
        $document = $word.Documents.Open($inputFilePath)

        $document.Fields.Update()

        # Update table of contents specifically
        foreach ($toc in $document.TablesOfContents) {
            $toc.Update()
        }

        # Save the updated Word document
        $document.Save() 

        # Check for any errors in fields (missing references)
        $missingReferences = $false
        foreach ($field in $document.Fields) {
            if ($field.Result.Text -match 'Error! Reference source not found') {
                $missingReferences = $true
                break
            }
        }

        if ($missingReferences) {
            throw "The document contains missing references."
        }

        # Hide comments
        $word.ActiveWindow.View.ShowRevisionsAndComments = $false
        $word.ActiveWindow.View.RevisionsFilter.Markup = [Microsoft.Office.Interop.Word.WdRevisionsMarkup]::wdRevisionsMarkupNone
        $word.ActiveWindow.View.RevisionsFilter.View = [Microsoft.Office.Interop.Word.WdRevisionsView]::wdRevisionsViewFinal

        # Export the document to PDF (17 is the WdSaveFormat enumeration for PDF)
        $document.SaveAs([ref] $outputFilePath, 17)
        
        # Close the document
        $document.Close($false)
    } catch {
        Write-Error "An error occurred: $_"
    } finally {
        # Quit the Word application
        $word.Quit()

        # Release the COM objects
        [System.Runtime.Interopservices.Marshal]::ReleaseComObject($document) | Out-Null
        [System.Runtime.Interopservices.Marshal]::ReleaseComObject($word) | Out-Null

        # Clean up
        Remove-Variable -Name document
        Remove-Variable -Name word
    }
}

# Enable this for debugging without launching the Job   
$testMode = $false

if($testMode)
{
    & $ProcessWordDocument $inputFilePath $outputFilePath
}
else
{
    # Start the Word processing job
    $job = Start-Job -ScriptBlock $ProcessWordDocument -ArgumentList $inputFilePath, $outputFilePath

    # Monitor the job with timeout
    $job | Wait-Job -Timeout $timeoutSeconds
    Receive-Job $job -ErrorAction Stop

    if ($job.State -eq 'Completed') {
    }
    elseif ($job.State -eq 'Failed') {
        Write-Output "Document processing Failed: " + $job.ChildJobs[0].Error + ($job.ChildJobs[0].JobStateInfo.Reason.Message)
    } else {
        Write-Output "Document processing timed out. Terminating job: " + $job.State
        Stop-Job -Job $job
    }
}

# Clean up any lingering Word processes
# Get-Process winword -ErrorAction SilentlyContinue | ForEach-Object { $_.Kill() }

if ((Test-Path $outputFilePath)) {
    exit 0
}
else
{
    exit 1
}