function Backup-LogFiles {
<#
.SYNOPSIS
    Saves old logs into an Archive subfolder.
#>
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory = $false)]
        [Alias("LogPath")]
        [string]$logDirectory,

        [Parameter(Mandatory = $false)]
        [Alias("CutoffDays")]
        [int]$archiveOlderThanDays = 0,

        [Parameter(Mandatory = $false)]
        [string]$filter = "*.log*"
    )

    $logLead = (Get-LogLeadName)

    if ([string]::IsNullOrEmpty($logDirectory)) {
        $logDirectory = (Get-OrbLogsPath)
    }

    if (!(Test-Path $logDirectory)) {
        Write-Warning "$logLead : Directory `"$logDirectory`" not found. Skipping.";
        return;
    }

    $archivePath = Join-Path $logDirectory "Archive";

    Write-Host "$logLead : Backing up / Archiving logs in `"$logdirectory`"";

    if (!(Test-Path $archivePath)) {
        New-Item $archivePath -ItemType Directory | Out-Null;
    }

    # Determine the cutoff date to archive files.
    $absoluteCutoff = [System.Math]::Abs($archiveOlderThanDays);
    $cutoffDate = (Get-Date).AddDays($absoluteCutoff * -1);
    $cutoffUtc = [System.TimeZoneInfo]::ConvertTimeToUtc($cutoffDate);

    # Remove any potential trailing wildcarded directories
    while ($logDirectory.Substring($logDirectory.get_length() - 2) -eq "\*" ) {
        Write-Host "Found a wildcard. Trimming..."
        $logDirectory = $logDirectory.Substring(0, $logDirectory.get_length() - 2)
    }

    # Tack on a single \* so that Get-ChildItem plays nicely with both the exclude and filter parameters

    $logDirectory = $logDirectory + "\*"

    # Figure out which files need to be archived.
    $logFiles = Get-ChildItem $logDirectory -Exclude *.zip, *.7z -Filter $filter -File | Where-Object { $_.LastWriteTimeUtc -lt $cutoffUtc }

    # Archive each file.
    $szPath = (Get-7ZipPath)
    foreach ($file in $logFiles) {
        Write-Verbose "Archiving $($file.FullName)";

        $archiveZip = $file.LastWriteTimeUtc.ToString("yyyy-MM-dd");
        $archiveZip = "$archiveZip.zip"
        $archiveZip = Join-Path $archivePath $archiveZip
        $archiveExists = Test-Path $archiveZip;

        # Figure out if the file is already in the zip.
        # We have to rename a file, and then add it, to prevent the original file in the zip from being overwritten.
        # This is particularly an issue if we do multiple deploys inside a day, which would overwrite the active log.
        $fileToArchive = $file.FullName;
        $tempPath = $null;
        try {
            if ($archiveExists) {
                # Search files inside the archive.
                $archiveFiles = (& $szPath l -r $archiveZip) | Where-Object { $_ -like "*$file*" -or $_ -like "*$($file.BaseName)_*$($file.Extension)" }
                $fileCount = $archiveFiles.count;

                if ($fileCount -gt 0) {
                    Write-Verbose "File name $($file.Name) already exists in the archive `"$archiveZip`" Creating a temporary log file copy & adding it to the archive.";

                    # Turns "C:/some/base/path/logname.log" into "C:/some/base/path/logname_2.log"
                    $tempFileName = "$($file.BaseName)_$fileCount$($file.Extension)"
                    $tempPath = Join-Path $file.Directory $tempFileName;

                    Copy-Item -Path $file.FullName -Destination $tempPath
                    $fileToArchive = $tempPath;
                }
            }

            try {
                & $szPath a -tzip -sdel -y $archiveZip $fileToArchive;
            } catch {
                Write-Warning $_.Exception;
            }

            # Clean up the original file if there was a pre-existing file in the archive.
            # 7-Zip removes a file when it adds it to an archive.
            if ($tempPath -and (Test-Path $file.FullName)) {
                Write-Verbose "Removing log $($file.FullName) because it was a duplicate filename in the `"$archiveZip`" archive."
                Remove-Item -Path $file.FullName -Force;
            }
        } catch {
            Write-Warning $_.Exception;
        } finally {
            # Remove temporary log files if zipping failed out for any reason.
            if ($tempPath -and (Test-Path $tempPath)) {
                Write-Verbose "Removing temporary log file copy `"$tempPath`"";
                Remove-Item -Path $tempPath -Force;
            }
        }
    }

    Write-Host "$logLead : Backup complete.";
}