ReplaceFont

# Parameters
param (
    [Parameter(Mandatory=$true)]
    [string]$FilePath,
    
    [Parameter(Mandatory=$true)]
    [string]$OriginalFont,
    
    [Parameter(Mandatory=$true)]
    [string]$NewFont
)

# Function to validate file path and extension
function Test-PowerPointFile {
    param ([string]$Path)
    if (-not (Test-Path $Path)) {
        Write-Error "File not found: $Path"
        return $false
    }
    if (-not ($Path -match "\.pptx?$")) {
        Write-Error "File must be a PowerPoint file (.ppt or .pptx)"
        return $false
    }
    return $true
}

try {
    # Validate input file
    if (-not (Test-PowerPointFile -Path $FilePath)) {
        exit 1
    }

    # Create PowerPoint application object
    $powerPoint = New-Object -ComObject PowerPoint.Application
    
    # Open the presentation
    $presentation = $powerPoint.Presentations.Open($FilePath)
    
    # Counter for changes
    $changes = 0
    
    # Loop through each slide
    foreach ($slide in $presentation.Slides) {
        # Loop through each shape in the slide
        foreach ($shape in $slide.Shapes) {
            # Check if shape has text
            if ($shape.HasTextFrame -eq -1) {  # -1 = msoTrue
                $textRange = $shape.TextFrame.TextRange
                # Check if the font matches the original font
                if ($textRange.Font.Name -eq $OriginalFont) {
                    # Change the font
                    $textRange.Font.Name = $NewFont
                    $changes++
                }
            }
        }
    }
    
    # Save and close the presentation
    $presentation.Save()
    $presentation.Close()
    
    # Quit PowerPoint
    $powerPoint.Quit()
    
    # Release COM objects
    [System.Runtime.Interopservices.Marshal]::ReleaseComObject($presentation) | Out-Null
    [System.Runtime.Interopservices.Marshal]::ReleaseComObject($powerPoint) | Out-Null
    [System.GC]::Collect()
    [System.GC]::WaitForPendingFinalizers()
    
    Write-Host "Font replacement complete. Changed $changes instances of $OriginalFont to $NewFont"
}
catch {
    Write-Error "An error occurred: $_"
    # Ensure PowerPoint is closed in case of error
    if ($presentation) {
        $presentation.Close()
    }
    if ($powerPoint) {
        $powerPoint.Quit()
    }
    # Release COM objects
    if ($presentation) {
        [System.Runtime.Interopservices.Marshal]::ReleaseComObject($presentation) | Out-Null
    }
    if ($powerPoint) {
        [System.Runtime.Interopservices.Marshal]::ReleaseComObject($powerPoint) | Out-Null
    }
    [System.GC]::Collect()
    [System.GC]::WaitForPendingFinalizers()
    exit 1
}