# open application
$App = New-Object -ComObject Powerpoint.Application
# open presentation
$pptx = $App.Presentations.Open("$pwd\dev\example.pptx")
# iterate through the existing slides
foreach ($slide in $pptx.Slides) {
    # write to the console to separate out the content from each slide
    Write-Host "`n(New Slide)`n"
    # iterate through the slide's shapes
    foreach ($shape in $slide.Shapes) {
        # retrieve any text that may be within said shape
        $text = $shape.TextFrame.TextRange.Text
        # if there's text, write it to the console
        if ($text.Length -gt 1) {
            Write-Host "`t$text"
        }
    }
}

$comparisonLayout = $pptx.SlideMaster.CustomLayouts | ? Name -match "Comparison"
$pptx.Slides.AddSlide($pptx.Slides.Count + 1, $comparisonLayout)

function Show-PptxLayouts {
	param(
		[ValidateScript({if($_){Test-Path $_}})]
		[string]$PptxTemplate
	)
    # open the app and presentation
	$PowerPointApp = New-Object -ComObject Powerpoint.Application
	$file = Get-Item $PptxTemplate
	$pptx = $PowerPointApp.Presentations.Open($file.FullName)
	# retrieve all of the slide master layouts
    $layouts = $pptx.SlideMaster.CustomLayouts
	# for each layout...
    for ($i = 1; $i -le $layouts.Count; $i++) {
		# create a new slide
        $active = $pptx.Slides.AddSlide($pptx.Slides.Count + 1, $layouts[$i])
		# get all the placeholders
        $placeholders = $active.Shapes.Placeholders
		# for each placeholder...
        for ($j = 1; $j -le $placeholders.Count; $j++) {
			$placeholder = $placeholders[$j]
			# add text indicating the placeholder index and name
            # (try/catch because some placeholders are for images, not text)
            try {
				$placeholder.TextFrame.TextRange.Text = `
					"Placeholder $j`: $($placeholder.Name)"
			} catch {}
		}
        # add a textbox to the slide to indicate the layout name and index
		$textbox = $active.Shapes.AddTextbox(1, 0, 0, 500, 100)
		$textRange = $textbox.TextFrame.TextRange
		$textRange.Text = "Layout $i`: $($layouts[$i].Name)"
		# RGB stored as the decimal representation of three 8-bit numbers
        # e.g., (249, 99, 220) --> 14443513
        $textRange.Font.Color.RGB = 14443513
		$textRange.Font.Size = 32
		$textRange.Font.Bold = $true
	}
    # remember to close the app!
	$PowerPointApp.Quit()
	# returns the pptx, leaving the user to save and close it
    return $pptx
}

$rgb = @(249, 99, 220)
$rgb[0] -bor ($rgb[1] -shl 8) -bor ($rgb[2] -shl 16)

function New-PptxFromCsv {
    param(
        [ValidateScript({if($_){Test-Path $_}})]
        [string]$PptxTemplate,
        [ValidateScript({if($_){Test-Path $_}})]
        [string]$Csv,
        [Parameter(mandatory=$true)]
        [string]$PptxName,
        [string]$DestinationFolder
    )
    # Validate destination folder
    try {
        $outFolder = Get-Item -Path $DestinationFolder 
    } catch {
        Write-Warning "Could not find folder at the provided path. " + `
            "Output will be saved in the current directory instead"
        $outFolder = $PWD
    }
    # get content
    $content = Get-Content -Path $Csv | ConvertFrom-Csv
    # copy before edit
    $outPath = "$outFolder\$PptxName.pptx"
    $iter = 1
    # ensure we don't overwrite an existing file
    while (Test-Path -Path $outPath) {
        $outPath = "$outFolder\$PptxName-$iter.pptx"
        $iter++
    }
    Copy-Item -Path $PptxTemplate -Destination $outPath
    $PowerPointApp = New-Object -ComObject Powerpoint.Application
    # expanded function signature allows us to hide the PowerPoint window
    $pptx = $PowerPointApp.Presentations.Open(
        $outPath, $false, $false, $false
    )
    # get all field names from the CSV (other than "Layout")
    $contentFields = (
        $content | Get-Member | Where { 
            $_.MemberType -eq "NoteProperty" -and $_.Name -ne "Layout" 
        }
    ).Name
    # for each CSV entry
    foreach ($slide in $content) {
        # create a slide of the designated layout
        $layout = $pptx.SlideMaster.CustomLayouts | ? Name -match $slide.Layout
        $newSlide = $pptx.Slides.AddSlide($pptx.Slides.Count + 1, $layout)
        # for each field in the CSV where there is content
        foreach ($field in $contentFields) {
            if ($slide.$field.Length -gt 0) {
                # add the CSV's content into the placeholder
                $placeholder = $newSlide.Shapes.Placeholders | `
                    ? Name -match $field
                $placeholder.TextFrame.TextRange.Text = $slide.$field
            }
        }
    }
    # save and exit
    $pptx.Save()
    $pptx.Close()
    $PowerPointApp.Quit()
}