# Convert-Delimiter.ps1
# A function to convert between different delimiters. E.g.: commas to tabs, etc.
##################################################################
# Written primarily as a way of enabling the use of Import-CSV when
# the source file was a columnar text file with data like services.txt:
#         ip              service         port
#         13.13.13.1      http            8000
#         13.13.13.2      https           8001
#         13.13.13.1      irc             6665-6669
# 
# Sample Use:  
#    Get-Content services.txt | Convert-Delimiter " +" "," | Set-Content services.csv
#         would convert the file above into something that could passed to:
#         Import-Csv services.csv
#
#    Get-Content Delimited.csv | Convert-Delimiter "," "`t" | Set-Content Delimited.tab
#         would convert a simple comma-separated-values file to a tab-delimited file
#
Function Convert-Delimiter([regex]$from,[string]$to) 
{ 
  process
  { 
    $_ = $_ -replace "(?:`"((?:(?:[^`"]|`"`"))+)(?:`"$from|`"`$))|(?:((?:.(?!$from))*.)(?:$from|`$))","Þ`$1`$2Þ$to" 
    $_ = $_ -replace "Þ(?:$to|Þ)?`$","Þ"
    $_ = $_ -replace "`"`"","`"" -replace "`"","`"`"" 
    $_ = $_ -replace "Þ((?:[^Þ`"](?!$to))+)Þ($to|`$)","`$1`$2"
    $_ = $_ -replace "Þ","`"" -replace "Þ","`""
    $_
  }
}

# Import-Delimited
# A replacement for Import-Csv that can handle other delimiters, and can import text from the pipeline
#
# Sample Use:
#     Import-Delimited " +" services1.txt 
# OR
#     ls services*.txt | Import-Delimited " +"
# OR
#     gc services2.txt | Import-Delimited " +"


Function Import-Delimited([regex]$delimiter=",", [string]$PsPath="")
{
  begin{
    $script:tmp = [IO.Path]::GetTempFileName()
    write-debug "Using tempfile $($script:tmp)"
    
    Function Import-String([string]$inputString){
      if($inputString.Length -gt 0 ) {
      write-debug "Importing $inputString"
      if(($inputString -as [IO.FileInfo]).Exists) {
        Get-Content $inputString | Convert-Delimiters $delimiter "," | Add-Content $script:tmp
      } elseif( ((Join-Path $pwd $inputString) -as [IO.FileInfo]).Exists) {
        Get-Content (Join-Path $pwd $inputString) | Convert-Delimiters $delimiter "," | Add-Content $script:tmp
      } else {
        $inputString | Convert-Delimiters  $delimiter "," | Add-Content $script:tmp
      }
      } else {
        write-debug "Nothing to Import"
      }
    }
    
    Import-String $PsPath
  }
  
  process{
    Import-String $_
  }
  end 
  {
    Import-Csv $script:tmp
  }
}