Split EDI X12 files using Powershell - powershell-2.0

Question

I am likely recreating the wheel here but this is my stab and solving an issue partly and asking for community assistance to resolve the remaining.
My task is to split EDI X12 documents into their own file (ISA to IEA)
and CRLF each line separately (similar to ex. EDI2.EDI below).
Below is my Powershell script and example EDI documents 1, 2 and 3.
My script will successfully split a contiguous X12 EDI document from ISA to IEA and CRLF into a file so that one contiguous string becomes something more readable. This works well and will even handle any segment delimiter as well as any line delimiter.
My issue is dealing with non-contiguous documents (ex. EDI2) or combined (ex. EDI3). The source folder could have any of the formatted files shown below. If the file already contains the CRLF, then I just need to split it from ISA to IEA. My script is failing when i pull in CRLF'd files.
Could someone help me solving this?
$sourceDir = "Z:\temp\EDI\temp\"
$targetDir = "Z:\temp\EDI\temp\archive"
<##### F U N C T I O N S #####>
<#############################>
Function FindNewFile
{
Param (
[Parameter(mandatory=$true)]
[string]$filename,
[int]$counter)
$filename = Resolve-Path $filename
$validFileName = "{0}\{1} {2}{3}" -f $targetDir, #([system.io.fileinfo]$filename).DirectoryName,
([system.io.fileinfo]$filename).basename,
$counter, #"1", #([guid]::newguid()).tostring("N"),
([system.io.fileinfo]$filename).extension
Return $validFileName
}
<###### M A I N L I N E ######>
<#############################>
If(test-path $sourceDir)
{
$files = #(Get-ChildItem $sourceDir | Where {!$_.PsIsContainer -and $_.extension -eq ".edi" -and $_.length -gt 0})
"{0} files to process. . ." -f $files.count
If($files)
{
If(!(test-path $targetDir))
{
New-Item $targetDir -ItemType Directory | Out-Null
}
foreach ($file in $files)
{
$me = $file.fullname
# Get the new file name
$isaCount = 1
$newFile = FindNewFile $me $isaCount
$data = get-content $me
# Reset variables for each new file
$dataLen = [int] $data.length
$linDelim = $null
$textLine = $null
$firstRun = $True
$errorFlag = $False
for($x=0; $x -lt $data.length; $x++)
{
$textLine = $data.substring($x, $dataLen)
$findISA = "ISA{0}" -f $textLine.substring(3,1)
If($textLine.substring(0,4) -eq $findISA)
{
$linDelim = $textLine.substring(105, 1)
If(!($FirstRun))
{
$isaCount++
$newFile = FindNewFile $me $isaCount
}
$FirstRun = $False
}
If($linDelim)
{
$delimI = $textLine.IndexOf($linDelim) + 1
$textLine = $textLine.substring(0,$delimI)
$fLine = $textLine
add-content $newFile $fLine
$x += $fLine.length - 1
$dataLen = $data.length - ($x + 1)
}
Else
{
$errorFlag = $True
"`t=====> {0} is not a valid EDI X12 file!" -f $me
$x += $data.length
}
}
If(!($errorFlag))
{
"{0} contained {1} ISA's" -f $me, $isaCount
}
}
}
Else
{
"No files in {0}." -f $sourceDir
}
}
Else
{
"{0} does not exist!" -f $sourceDir
}
Filename: EDI1.EDI
ISA*00* *00* *08*925xxxxxx0 *01*78xxxx100 *170331*1630*U*00401*000000114*0*P*>~GS*FA*8473293489*782702100*20170331*1630*42*T*004010UCS~ST*997*116303723~SE*6*116303723~GE*1*42~IEA*1*000000114~ISA*00* *00* *08*WARxxxxxx *01*78xxxxxx0 *170331*1545*U*00401*000002408*0*T*>~GS*FA*5035816100*782702100*20170331*1545*1331*T*004010UCS~ST*997*000001331~~SE*24*000001331~GE*1*1331~IEA*1*000002408~
Filename: EDI2.EDI
ISA*00* *00* *ZZ*REINxxxxxxxDSER*01*78xxxx100 *170404*0819*|*00501*100000097*0*P*}~
GS*PO*REINHxxxxxxDSER*782702100*20170404*0819*1097*X*005010~
ST*850*1097~
SE*14*1097~
GE*1*1097~
IEA*1*100000097~
Filename: EDI3.EDI
ISA*00* *00* *08*925xxxxxx0 *01*78xxxx100 *170331*1630*U*00401*000000114*0*P*>~GS*FA*8473293489*782702100*20170331*1630*42*T*004010UCS~ST*997*116303723~SE*6*116303723~GE*1*42~IEA*1*000000114~ISA*00* *00* *08*WARxxxxxx *01*78xxxxxx0 *170331*1545*U*00401*000002408*0*T*>~GS*FA*5035816100*782702100*20170331*1545*1331*T*004010UCS~ST*997*000001331~~SE*24*000001331~GE*1*1331~IEA*1*000002408~
ISA*00* *00* *ZZ*REINxxxxxxxDSER*01*78xxxx100 *170404*0819*|*00501*100000097*0*P*}~
GS*PO*REINHxxxxxxDSER*78xxxxxx0*20170404*0819*1097*X*005010~
ST*850*1097~
SE*14*1097~
GE*1*1097~
IEA*1*100000097~
FWIW, I've compiled this code from all over the net including stackoverflow.com. If you see your code and desire recognition, let me know and I'll add it. I'm not claiming any of this is original! My motto is "ARRRGH!"

Answer 1

EDI3 is an invalid X12 document, each file should only contain one ISA segment with repeated envelopes if required.
The segment terminator should also be consistent. In EDI3 it is both ~ and ~ which is again invalid.

Answer 2

Segment terminator should be tilde "~".
It can be suffixed by: nothing, "\n" or, "\r\n", what is optional is the suffix for human reading. Some implementations might be more relaxed in terms of the X12 standard.
https://www.ibm.com/support/knowledgecenter/en/SS6V3G_5.3.1/com.ibm.help.gswformstutscreen.doc/GSW_EDI_Delimiters.html
https://docs.oracle.com/cd/E19398-01/820-1275/agdbj/index.html
https://support.microsoft.com/en-sg/help/2723596/biztalk-2010-configuring-segment-terminator-for-an-x12-encoded-interch
BTW, check my splitter/viewer: https://gist.github.com/ppazos/94a63ab18910ab0c0d23c9ff4ff7e5c2