Replace-ByNewerFileVersion.psm1

<#
.SYNOPSIS
    Replaces a target file with a reference file if the reference file has a newer file version.

.DESCRIPTION
    The function replaces a target file with a reference file if the reference file has a newer file version.

.PARAMETER ReferencePath
    The path to the reference file. This file will be used to determine whether the target file should be replaced.
    
.PARAMETER TargetPath
    The path to the target file. This file will be replaced with the reference file if the reference file has a newer file version.

.PARAMETER DryRun
    If this switch is set, the function will not replace the target file with the reference file. Instead, it will output a message indicating whether the reference file has a newer file version than the target file.

.EXAMPLE
    Replace-ByNewerFileVersion -TargetPath "C:\Program Files\MyApp\MyApp.exe" -ReferencePath "C:\Downloads\MyApp.exe"
    Replaces the target file "C:\Program Files\MyApp\MyApp.exe" with the reference file "C:\Downloads\MyApp.exe" if the reference file has a newer file version.
#>
function Replace-ByNewerFileVersion {
    param (
        [Parameter(Mandatory = $true)]
        [string]$ReferencePath,
        [Parameter(Mandatory = $true)]
        [string]$TargetPath,
        [Parameter(Mandatory = $false)]
        [switch]$DryRun,
        [Parameter(Mandatory = $false)]
        [switch]$TerminateBeforeReplace
    )

    $referenceVersion = [System.Version](Get-Item $ReferencePath).VersionInfo.FileVersion

    $targetFile = Get-Item $TargetPath
    $targetVersion = [System.Version]($targetFile).VersionInfo.FileVersion


    Write-Host "Reference file version: $referenceVersion"
    Write-Host "Target file version: $targetVersion"

    $isReferenceVersionNewer = $referenceVersion -gt $targetVersion

    $runningProcesses = Get-Process | Where-Object { $_.Path -eq $targetFile.FullName }

    if ($runningProcesses.Count -eq 0) {
        Write-Output "No running processes found for the target file."
    }
    else {
        Write-Host "Running processes of the target file:"
        $runningProcesses | Select-Object -Property Id, Name, Path
    }

    if ($DryRun) {
        if ($isReferenceVersionNewer) {
            Write-Output "The reference file has a newer file version than the target file."
        }
        else {
            Write-Output "The reference file does not have a newer file version than the target file."
        }
        
        return $null
    }

    if ($isReferenceVersionNewer) {
        if ($TerminateBeforeReplace) {
            Write-Output "The reference file has a newer file version than the target file. Terminating the process before replacing the target file."

            Write-Host "Terminating running processes for the target file"
            $runningProcesses | Stop-Process -Force

            Start-Sleep -Seconds 3
        }

        Copy-Item -Path $ReferencePath -Destination $TargetPath -Force
        Write-Output "The target file has been replaced with the reference file."
    }
    else {
        Write-Output "The target file has not been replaced with the reference file because the reference file does not have a newer file version."
    }

    return $null
}