# To run this script, launch PowerShell and first enter: set-executionpolicy remotesigned
# Proceed to the script folder, or enter the game's save folder below - you'll also need a full backup path
# Then, enter .\SaveWatcher to run the file

#config
$SaveFileWildcard = 'm3_*_save'    # Wildcard that saves and only saves match. Usually *.sav. BE CAREFUL. Wrong wildcard can cause a loop!
$PrimaryBackupPath = 'Backups' # This folder will be used to get the Previous.Save from. Absolute path preferred.
#$PreviousSaveFile = "Previous.Save" # How to call the second-to-last save - this is the one you'll usually want to restore.

# Advanced options
$subfolders = $false # Recommended $false for safety. Use $true for games like Mass Effect with save subfolders.
$AppendTimestampFormat = ".yyyy-MM-dd.HH-mm-ss.backup"
$MultipleFolders = "" #"P:\BCK\Saves\Metro",...
$LogFileName = "SaveWatcher.log" # Absolute paths can be used
$SpecifiedLocation = $false # If false, saves will be grabbed from the script's folder
$SaveLocation = ""
$Verbose = $true # Show debug messages?
#

if ($Verbose) {Write-Host "Killing old event"}
# Kill old event
Unregister-Event SaveWatcherInstance
# Find own path
If (!($SpecifiedLocation)) {
   $invocation = (Get-Variable MyInvocation).Value
   $SaveLocation = Split-Path $invocation.MyCommand.Path
   if (!(Test-Path -Path $PrimaryBackupPath)) {
     md $PrimaryBackupPath }
   }

if ($Verbose) {Write-Host "Killed old event"}
# Events
$message = new-object psobject -property @{PrimaryBackupPath = $PrimaryBackupPath; folder = $SaveLocation; subfolders = $subfolders; PreviousSaveFile = $PreviousSaveFile; AppendTimestampFormat = $AppendTimestampFormat; AbsoluteBackupPath = $AbsoluteBackupPath; LogFileName = $LogFileName; Verbose=$Verbose; MultipleFolders = $MultipleFolders; UseMultipleFolders = $UseMultipleFolders}
$SaveWatcherScript = New-Object IO.FileSystemWatcher $SaveLocation, $SaveFileWildcard -Property @{IncludeSubdirectories = $subfolders;NotifyFilter = [IO.NotifyFilters]'FileName, LastWrite'}

if ($Verbose) {Write-Host "Registering event $SaveLocation"}


Register-ObjectEvent $SaveWatcherScript Changed -SourceIdentifier SaveWatcherInstance -MessageData $message -Action {
Write-Host "Triggered"
   $name = $Event.SourceEventArgs.Name
   $fullname = $Event.SourceEventArgs.FullPath
   $time = $Event.TimeGenerated
   $logfile = $event.MessageData.LogFileName
   $timeS = $time.ToString($event.MessageData.AppendTimestampFormat)
   $path = Split-Path $fullname
   $BackupCopyFileName = $event.MessageData.PrimaryBackupPath + "\" + $name + $timeS
   $dupe = $false

   if (Test-Path -Path $logfile) {
      if ($event.MessageData.PreviousSaveFile) {$lastcopy = Get-Content $logfile -Tail 1}
      if ($Event.MessageData.Verbose) {Write-Host "Debug step 3 $lastcopy"}
      if ($event.MessageData.PreviousSaveFile) {
         $PreviousSave = $event.MessageData.PreviousSaveFile
         if (Test-Path -Path $lastcopy) {
            if ($lastcopy -ne $BackupCopyFileName) {
              Out-File -FilePath $logfile -Append -InputObject "$time Last line of the log is a file $lastcopy. Copying to previous save at: $PreviousSave"
              if ($event.MessageData.Verbose) {Write-Host "New save is $BackupCopyFileName, last logged save is $lastcopy, copying to previous save at: $PreviousSave"}
               Copy-Item $lastcopy -Destination $PreviousSave
               }
            else {
               if ($event.MessageData.Verbose) {Write-Host "New save is $BackupCopyFileName, last logged save is $lastcopy - double trigger detected"}
               $dupe = $true
               }
            }   
         else {
           Out-File -FilePath $logfile -Append -InputObject "$time Last line of the log is not a valid file. Previous save functionality is invalid."
           }      
         }
      }
   else {
      Out-File -FilePath $logfile -Append -InputObject "$time No log file '$logfile' found. Previous save functionality is invalid."
      }

   if (($Event.MessageData.MultipleFolders) -And !($dupe)) {
      foreach ($dir in $event.MessageData.MultipleFolders) {
         $extracopy = $dir + "\" + $name + $timeS
         if (!(Test-Path -Path $dir)) {
           md $dir }
         Copy-Item $name -Destination $extracopy
         if ($event.MessageData.Verbose) {Out-File -FilePath $logfile -Append -InputObject "$time New version of file '$name'. Secondary backup created at: $extracopy"}
         }
      }
   If (!($dupe)) {
      Copy-Item $name -Destination $BackupCopyFileName
      Out-File -FilePath $logfile -Append -InputObject "$time New version of file '$name'. Updated file copied to: `r`n$BackupCopyFileName"
      if ($event.MessageData.Verbose) {Write-Host "Backed up file '$name' at $time"}
      }
}

# To run this script, launch PowerShell and first enter: set-executionpolicy remotesigned
# Proceed to the script folder, or enter the game's save folder below - you'll also need a full backup path
# Then, enter .\SaveWatcher to run the file

#config
$SaveFileWildcard = 'm3_*_save'    # Wildcard that saves and only saves match. Usually *.sav. BE CAREFUL. Wrong wildcard can cause a loop!
$PrimaryBackupPath = 'Backups' # This folder will be used to get the Previous.Save from. Absolute path preferred.
#$PreviousSaveFile = "Previous.Save" # How to call the second-to-last save - this is the one you'll usually want to restore. (Not automated yet)

# Advanced options
$Verbose = $true # Show debug messages?
$AppendTimestampFormat = ".yyyy-MM-dd.HH-mm-ss.backup"
$subfolders = $false # Recommended $false for safety. Use $true for games like Mass Effect with save subfolders.
$MultipleFolders = "" #"Onedrive", "P:\BCK\Saves\Metro",...
$LogFileName = "SaveWatcher.log" # Absolute paths can be used
$SpecifiedLocation = $false # If false, saves will be grabbed from the script's folder
$SaveLocation = ""
#

if ($Verbose) {Write-Host "Killing old event"}
# Kill old event
Unregister-Event SaveWatcherInstance
# Find own path
If (!($SpecifiedLocation)) {
   $invocation = (Get-Variable MyInvocation).Value
   $SaveLocation = Split-Path $invocation.MyCommand.Path
   if (!(Test-Path -Path $PrimaryBackupPath)) {
     md $PrimaryBackupPath }
   }

if ($Verbose) {Write-Host "Killed old event"}
# Events
$message = new-object psobject -property @{PrimaryBackupPath = $PrimaryBackupPath; folder = $SaveLocation; subfolders = $subfolders; PreviousSaveFile = $PreviousSaveFile; AppendTimestampFormat = $AppendTimestampFormat; AbsoluteBackupPath = $AbsoluteBackupPath; LogFileName = $LogFileName; Verbose=$Verbose; MultipleFolders = $MultipleFolders; UseMultipleFolders = $UseMultipleFolders}
$SaveWatcherScript = New-Object IO.FileSystemWatcher $SaveLocation, $SaveFileWildcard -Property @{IncludeSubdirectories = $subfolders;NotifyFilter = [IO.NotifyFilters]'FileName, LastWrite'}

if ($Verbose) {Write-Host "Registering event $SaveLocation"}


Register-ObjectEvent $SaveWatcherScript Changed -SourceIdentifier SaveWatcherInstance -MessageData $message -Action {
Write-Host "Triggered"
   $name = $Event.SourceEventArgs.Name
   $fullname = $Event.SourceEventArgs.FullPath
   $time = $Event.TimeGenerated
   $logfile = $event.MessageData.LogFileName
   $timeS = $time.ToString($event.MessageData.AppendTimestampFormat)
   $path = Split-Path $fullname
   $BackupCopyFileName = $event.MessageData.PrimaryBackupPath + "\" + $name + $timeS
   $dupe = $false

   if (Test-Path -Path $logfile) {
      if ($event.MessageData.PreviousSaveFile) {$lastcopy = Get-Content $logfile -Tail 1}
      if ($Event.MessageData.Verbose) {Write-Host "Debug step 3 $lastcopy"}
      if ($event.MessageData.PreviousSaveFile) {
         $PreviousSave = $event.MessageData.PreviousSaveFile
         if (Test-Path -Path $lastcopy) {
            if ($lastcopy -ne $BackupCopyFileName) {
              Out-File -FilePath $logfile -Append -InputObject "$time Last line of the log is a file $lastcopy. Copying to previous save at: $PreviousSave"
              if ($event.MessageData.Verbose) {Write-Host "New save is $BackupCopyFileName, last logged save is $lastcopy, copying to previous save at: $PreviousSave"}
               Copy-Item $lastcopy -Destination $PreviousSave
               }
            else {
               if ($event.MessageData.Verbose) {Write-Host "New save is $BackupCopyFileName, last logged save is $lastcopy - double trigger detected"}
               $dupe = $true
               }
            }   
         else {
           Out-File -FilePath $logfile -Append -InputObject "$time Last line of the log is not a valid file. Previous save functionality is invalid."
           }      
         }
      }
   else {
      Out-File -FilePath $logfile -Append -InputObject "$time No log file '$logfile' found. Previous save functionality is invalid."
      }

   if (($Event.MessageData.MultipleFolders) -And !($dupe)) {
      foreach ($dir in $event.MessageData.MultipleFolders) {
         $extracopy = $dir + "\" + $name + $timeS
         if (!(Test-Path -Path $dir)) {
           md $dir }
         Copy-Item $name -Destination $extracopy
         if ($event.MessageData.Verbose) {Out-File -FilePath $logfile -Append -InputObject "$time New version of file '$name'. Secondary backup created at: $extracopy"}
         }
      }
   If (!($dupe)) {
      Copy-Item $name -Destination $BackupCopyFileName
      Out-File -FilePath $logfile -Append -InputObject "$time New version of file '$name'. Updated file copied to: `r`n$BackupCopyFileName"
      if ($event.MessageData.Verbose) {Write-Host "Backed up file '$name' at $time"}
      }
}