Get-ADUser account name whose email address matches any of the emails indicated in csv file - powershell

Question

I have a comma-separated csv file as below (first row is the header):
category;email.1;email.2;email.3;email.4;email.5;email.6
category1;sample#gmail.com;;;;;
category2;;;sample2#gmail.com;;;
category3;;sample3#gmail.com;;sample44#hotmail.com;;sample55#gmail.com
and so on...
Now I import it:
$emails = Import-CSV -Encoding Default -Delimiter ";" "c:\temp\myFile.csv"
And finally, for each row in the csv I want to get the AD user account name whose email address matches any from email.1 to email.6
So I try this using a foreach loop but I have no idea what have to put within it to get what I want.
$emails | foreach {
$userAccountName = Get-ADUser -filter {something}
# do some stuff with $userAccountName
}
Note: I would like a generic solution taking into account that in future can be more than 6 emails by category. Also take into account that some emails can be empty for the category.

Answer 1

Once imported you can enumerate the headers matching a pattern
$emails = Import-CSV -Encoding Default -Delimiter ";" "c:\temp\myFile.csv"
$EmailHeaders = ($Emails[0].psobject.Properties|Where-Object Name -like 'email.*').Name
ATM this returns:
> $EmailHeaders
email.1
email.2
email.3
email.4
email.5
email.6
Nest foreachs's to iterate the emails per row which are populated.
Get-ADUser commented out for testing
foreach($Row in $Emails){
foreach($EmailHeader in $EmailHeaders){
if($Email=$Row.$EmailHeader){
[PSCustomObject]#{
Category = $Row.Category
Email_x = $EmailHeader
Email = $Email
SamAccountName= $Null #(Get-ADUser -Filter {EmailAddress -eq "$Email"} -Properties SamAccountName).SamAccountName
}
}
}
}
Category Email_x Email SamAccountName
-------- ------- ----- --------------
category1 email.1 sample#gmail.com
category2 email.3 sample2#gmail.com
category3 email.2 sample3#gmail.com
category3 email.4 sample44#hotmail.com
category3 email.6 sample55#gmail.com