Itunes_Save-R-PC-SC.ps1

<#
file named - Itunes_Save-R-PC-SC.ps1

what it does
- reads rating, playedcount, skippedcount values from itunes
- builds a new comment string with the current values in it
- compares to existing comment and replaces it if different

not currently testing in advance to see if SHOULD update comment field cuz ...
- original version that did so was way too slow
- building & then testing newcomment for changes against oldcomment was easier

used string operator "-replace" instead of string method cuz ...
- easier to get non-case-sensitive matches
- more tolerant of errors [can do a -replace on a string with nothing to replace & gets no error]

used "-match" anyway cuz ...
- not testing for presence of to-be-replaced-string makes me uneasy
- may want to switch to string methods if time would be saved

currently runs 1000 tracks in ~ 5 minutes if they all need to be changed
currently runs 1000 tracks in ~ 30 seconds if none need to be changed

that seems to be fast enuf to auto-run daily with task scheduler

#>

# function list start

# write to console/file/both
function WriteTo($what, [String]$where, [String]$filename)
    {
    if($where -ne "console" -and $filename -eq "")
        {
        $filename = -join ($Env:Temp, "\", "PowerShell_LogFile_", (get-date).ToString("yyyy-MM-dd"), ".log")
        }
    switch($where.ToLower())
        {
        "console" {$what | Write-Host}
        "file"    {Add-Content -path $filename -value $what}
        "both"    {Add-Content -path $filename -value $what -passthru}
        default   {$what | Write-Host}
        }
    }

# trim spaces from each end and reduce multi-spaces to one space
function TrimSpaces([String]$in)
    {
    ($in -replace "\s{2,}", " ").Trim()
    }

# function list end

$ItunesAlreadyRunning = (Get-Process | Where-Object {$_.ProcessName -eq "iTunes"}) -match "iTunes"

$iTunesApp = New-Object -comObject iTunes.Application
$iMainLibrary = $iTunesApp.LibraryPlaylist
$iTracks = $iMainLibrary.Tracks

$NumTracks = $iTracks.Count
# itunes no longer uses "1" to represent ONLY the audio file "kind".
# - that also is used for books and possibly other file "kind" info.
# - switched to using "KindAsString" instead of "Kind" value for media type test.
$AudioTrack = "MPEG audio file"
$LogFile = -join ($Env:Temp, "\", $myinvocation.mycommand.name, "_", (get-date).ToString("yyyy-MM-dd"), ".log")
$StartTime = Get-Date

# swap these two when you wanna test just a few tracks
$x = $NumTracks
#$x = 10

$ProcessedCount = 0
$ChangedCount = 0
while($x -gt 0)
    {
    $ProcessedCount ++
    $iCurrentItem = $iTracks.Item($x)
    if($iCurrentItem.KindAsString -eq $AudioTrack)
        {
        $Rating = $iCurrentItem.Rating
        $PlayedCount = $iCurrentItem.PlayedCount
        $SkippedCount = $iCurrentItem.SkippedCount
        $Location = $iCurrentItem.Location
        $NewComment = $OldComment = $iCurrentItem.Comment
        $ComRating = -join ("rating=", $Rating)
        $ComPlayedCount = -join ("playedcount=", $PlayedCount)
        $ComSkippedCount = -join ("skippedcount=", $SkippedCount)
        if($NewComment.length -gt 0)
            {
            # remove existing rating in the comment field
            if($NewComment -match "rating=\d{1,3}")
                {
                $NewComment = $NewComment -replace "rating=\d{1,3}", ""
                }
            # remove existing playedcount in the comment field
            if($NewComment -match "playedcount=\d{1,}")
                {
                $NewComment = $NewComment -replace "playedcount=\d{1,}", ""
                }
            # remove existing skippedcount in the comment field
            if($NewComment -match "skippedcount=\d{1,}")
                {
                $NewComment = $NewComment -replace "skippedcount=\d{1,}", ""
                }
            }
        # append current rating, playedcount, skippedcount to comment with a spacer space
        $NewComment = $NewComment, $ComRating, $ComPlayedCount, $ComSkippedCount -join " "
        # spaces clean up
        $NewComment = TrimSpaces $NewComment
        # write the new comment to itunes if it actually changed
        if($NewComment -ne $OldComment)
            {
            $iCurrentItem.Comment = $NewComment
            $ChangedCount ++
            }
        #show what was done
        "track index            = $x"
        Write-Host ""
        "track rating           = $Rating"
        "track playedcount      = $PlayedCount"
        "track skippedcount     = $SkippedCount"
        Write-Host ""
        "OLD track comment      = $OldComment"
        "NEW track comment      = $NewComment"
        Write-Host ("itunes track comment   =", $iCurrentItem.Comment)
        "track location         = $Location"
        Write-Host "******************************"
        Write-Host ""
        }
    $x --
    }

# if itunes was NOT already running
#   and itunes is NOT currently playing
#   then we started it and we are not using it, so shut it down
if((-not $ItunesAlreadyRunning) -and ($itunesApp.Playerstate -eq "0"))
    {
    $iTunesApp.Quit()
    }

$StopTime = Get-Date
$TotalTime = $StopTime - $StartTime

WriteTo (-join ("started at = ", $StartTime)) "both" $LogFile
WriteTo (-join ("stopped at = ", $StopTime)) "both" $LogFile
WriteTo (-join ("total time = ", $TotalTime.ToString())) "both" $LogFile
WriteTo (-join ("processed  = ", $ProcessedCount)) "both" $LogFile
WriteTo (-join ("changed    = ", $ChangedCount)) "both" $LogFile
WriteTo (-join ("log file   = ", $LogFile)) "both" $LogFile
WriteTo ("") "both" $LogFile