ps-read file and remove leading space from filenames

<#
.SYNOPSIS
    Renames specified files by removing the first character of their filenames.
.DESCRIPTION
    This script processes a list of provided file paths. For each file, it removes the
    first character of its name (filename + extension) and renames the file.
    It includes a -WhatIf parameter to preview changes without applying them.
    The script will skip renaming if the original filename has only one character (as removing it would result in an empty name)
    or if a file with the new name already exists.
.PARAMETER FullName
    An array or file of full paths to the files that need to be renamed. This parameter is mandatory
    and can accept input from the pipeline (e.g., from Get-ChildItem or Get-Content).
.EXAMPLE
**    .\rrspace.ps1 -FullName "C:\temp\1example.txt", "C:\data\2another.log"
    Description: Attempts to rename "C:\temp\1example.txt" to "example.txt" and
                 "C:\data\2another.log" to "another.log".

.EXAMPLE
    Get-ChildItem "C:\reports\*.tmp" | .\Rename-RemoveFirstChar.ps1
    Description: Finds all .tmp files in "C:\reports\" and pipes them to the script
                 to have their first character removed from their names.

.EXAMPLE
    Get-Content "C:\ListOfFilesToRename.txt" | .\Rename-RemoveFirstChar.ps1 -WhatIf
    Description: Reads a list of file paths from "C:\ListOfFilesToRename.txt",
                 and shows what renames would occur without actually performing them.
                 Each line in the text file should be a full path to a file.

.EXAMPLE
    $fileList = @("C:\docs\Xfile1.docx", "C:\docs\_file2.pdf")
    .\Rename-RemoveFirstChar.ps1 -FullName $fileList -Verbose
    Description: Renames files specified in the $fileList array and provides verbose output.
.EXAMPLE
    Expected text file format of paths\files to be renamed (can also use mapped drive instead of \\<server>\<share>),
        one path/file per line:
    \\NJHYFS\depts\ENGIN\Doug R\Teterboro Airport Submittals\ Potential Spam   TEB - 914 205 United Water field meeting.msg
    \\NJHYFS\depts\ScanDocuments\Direct_Debit\Daily Work\2016\JAN 2016\6\ 100_8957622222_01062016.pdf
    b:\ENGIN\Doug R\Teterboro Airport Submittals\ Potential Spam   TEB - 914 205 United Water field meeting.msg
    b:\ScanDocuments\Direct_Debit\Daily Work\2016\JAN 2016\6\ 100_8957622222_01062016.pdf
.OUTPUTS
    None by default, unless -Verbose or -WhatIf is used.
    When -WhatIf is used, it outputs messages indicating what rename operations would occur.
.NOTES
    Author: Gemini
    Date: 2025-05-19
    It's highly recommended to run the script with -WhatIf first to ensure it targets the correct files
    and the new names are as expected.
    Files with names that are only one character long will be skipped.
    If a file with the target new name already exists in the same directory, the rename
      operation for that specific file will be skipped.
#>
[CmdletBinding(SupportsShouldProcess)] # Enables -WhatIf and -Confirm
param (
  [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true, Position = 0)]
    [string[]]$SourceFile, # Accepts an array of file paths, also supports FullName property from piped FileInfo objects
  [Parameter(Mandatory)]
    [string]$logFilePrefix # date will be calculated and added in the next section in addition the extension .log
)

begin {
  $begTime = Get-Date
  $filesProcessedCount = 0
  $filesRenamedCount = 0
  $renameThese = Get-Content -Path $SourceFile
  $warningFGcolor = "Yellow"
  $warningBGcolor = "DarkRed"
  $logupdateFGcolor = "White"
  $logupdateBGcolor = "DarkBlue"
  $logFilePrefix = $logFilePrefix + "-" + $((Get-Date).ToString('yyyy-MM-dd_HH-mm-ss')) + ".log"

  # Start-Transcript -Path $logFile

  #Write-Host "Script started, reading $SourceFile ($($renameThese.Count) files)." -ForegroundColor Green -BackgroundColor DarkGray
  $logthis = "Script started $begtime, reading $SourceFile ($($renameThese.Count) files).`n"
  $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor Green -BackgroundColor DarkGray
}

process {
  foreach ($filePathInput in $renameThese) {
    $filesProcessedCount++
    #Write-Host "Processing input: '$filePathInput' `n($($filesProcessedCount) of $($renameThese.count))" -ForegroundColor Blue
    $logthis = "Processing input: '$filePathInput' `n($($filesProcessedCount) of $($renameThese.count))"
    $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor Blue
    # Resolve the path to ensure it's a valid file path and get FileInfo object
    try {
        $FileItem = Get-Item -LiteralPath $filePathInput -ErrorAction Stop
    }
    catch {
        $logthis = "'$filePathInput' could not be found or accessed. Error: $($_.Exception.Message).`n...Skipping"
        #Write-Warning $logthis
        $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor $warningFGcolor -BackgroundColor $warningBGcolor
        continue
    }

    # Ensure it's a file, not a directory
    if ($FileItem.GetType().Name -ne "FileInfo") {
        $logthis = "'$($FileItem.Name)' is not a file, skipping..."
        #Write-Warning "'$($FileItem.Name)' is not a file, skipping..."
        $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor $warningFGcolor -BackgroundColor $warningBGcolor
        continue
    }

    $OriginalFullName = $FileItem.FullName
    $OriginalName = $FileItem.Name
    $DirectoryPath = $FileItem.DirectoryName

    # Check if the filename has enough characters to remove the first one
    if ($OriginalName.Length -lt 2) {
        $logthis = "File '$OriginalFullName' has a name '$OriginalName' which is too short (less than 2 characters) to remove the first character.`n...Skipping"
        #Write-Warning $logthis
        $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor $warningFGcolor -BackgroundColor $warningBGcolor
        continue
    }

    # Generate the new name by removing the first character
    $NewName = $OriginalName.TrimStart()

    # This check is technically covered by the Length -lt 2, but good for clarity
    #if ([string]::IsNullOrWhiteSpace($NewName)) {
    #    Write-Warning "Skipping file '$OriginalFullName' as removing the first character would result in an empty filename."
    #    continue
    #}

    # Construct the new full path
    $NewFileFullName = Join-Path -Path $DirectoryPath -ChildPath $NewName

    # Check if a file with the new name already exists
    if (Test-Path -LiteralPath $NewFileFullName) {
        $logthis = "Skipping rename of '$OriginalFullName': A file named '$NewName' already exists at '$DirectoryPath'"
        #Write-Warning $logthis
        $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor $warningFGcolor -BackgroundColor $warningBGcolor
        continue
    }

    Write-Host "Preparing to rename '$OriginalName'`n to '$NewName' `nin directory '$DirectoryPath'" -ForegroundColor White

    # Perform the rename operation, respecting -WhatIf
    if ($PSCmdlet.ShouldProcess($OriginalFullName, "Rename to '$NewFileFullName' (removing first character)")) {
        try {
          Rename-Item -LiteralPath $OriginalFullName -NewName $NewName -ErrorAction Stop
          $logthis = "Successfully renamed: '$OriginalFullName' to '$NewFileFullName'"
          $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host  -ForegroundColor $logupdateFGcolor -BackgroundColor $logupdateBGcolor
          $filesRenamedCount++
        }
        catch {
          #Write-Error "Failed to rename '$OriginalFullName' to '$NewName'.`n Error: $($_.Exception.Message)"
          $logthis = "Failed to rename '$OriginalFullName' to '$NewName'. Error: $($_.Exception.Message)"
          $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Error
        }
    }
  }
}

end {
  Write-Host "Total files processed: $filesProcessedCount"

  if ($PSCmdlet.WhatIfPreference) {
      Write-Host "--- WhatIf Mode: No changes were made. ---"
  } elseif ($filesRenamedCount -eq 0 -and $filesProcessedCount -gt 0) {
      Write-Host "No files were renamed. Check warnings or verbose output for details."
  } elseif ($filesProcessedCount -eq 0) {
      Write-Host "No file paths were provided or found to process."
  }

#  Stop-Transcript
  $endTime = Get-Date
  #$endTime
  $totalTime = New-TimeSpan -Start $begTime -End $endTime | Select-Object -Property TotalSeconds, TotalMinutes

  #Write-Host "end of script; Total files successfully renamed: $filesRenamedCount" -ForegroundColor Green -backgroundColor DarkGray
  $logthis = "`nend of script: $endTime `n$totalTime`nTotal files successfully renamed: $filesRenamedCount"
  $logthis | Tee-Object -FilePath $logFilePrefix -Append | Write-Host -ForegroundColor Green -backgroundColor DarkGray
}