addBulkUsersFromCsv.ps1

# Load in csv file for employee data


function Get-EmployeeFromCsv{
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory)]
        [string]$FilePath,
        [Parameter(Mandatory)]
        [string]$Delimiter,
        [Parameter(Mandatory)]
        [hashtable]$SyncFieldMap
    )

    try{
        $SyncProperties=$SyncFieldMap.GetEnumerator()
        $Properties=ForEach($Property in $SyncProperties){
            @{Name=$Property.Value;Expression=[scriptblock]::Create("`$_.$($Property.Key)")}
        }
        Import-Csv -Path $FilePath -Delimiter $Delimiter | Select-Object -Property $Properties
    }catch{
        Write-Error $_.Exception.Message
    }
}


# can modify to add/remove or change attributes
$SyncFieldMap=@{
    First_Name="GivenName"
    Last_Name="SurName"
    Department="Department"
    Title="Title"
    Start_Date="Start_Date"
    Temp_Password="Temp_Password" 
}

$DepartmentOU_Map = @{
    "Sales"="OU=Sales-Users, DC=mydomain, DC=com"
    "Finance"="OU=Finance-Users, DC=mydomain, DC=com"
    "Human Resources"="OU=HR-Users, DC=mydomain, DC=com"
    "IT"="OU=IT-Users, DC=mydomain, DC=com"
    "Marketing"="OU=Marketing-Users, DC=mydomain, DC=com"
}


$Employees = Get-EmployeeFromCsv -FilePath "MOCK_DATA.csv" -Delimiter "," -SyncFieldMap $SyncFieldMap

# loop to create users from csv
foreach ($Employee in $Employees) {
    $givenName = $Employee.GivenName.Trim()
    $surName = $Employee.Surname.Trim()
    $department = $Employee.Department

    $cleanFirst = $givenName -replace "[^a-zA-Z0-9]"
    $cleanLast = $surName -replace "[^a-zA-Z0-9]"


    $trySamAccountName = ($cleanFirst.Substring(0,1) + $cleanLast).ToLower()
    $samAccountName = $trySamAccountName
    $upn = "$trySamAccountName@mydomain.com"
    $i = 1

    
    # if samAccountName or UserPrincipalName are not unique, append a number and increment until unique
    do{
        $escapedSamAccountName = $samAccountName -replace "'", "''"
        $escapedUpn = $upn -replace "'", "''"
        $existingUser = Get-ADUser -Filter "SamAccountName -eq '$escapedSamAccountName' -or UserPrincipalName -eq '$escapedUpn'" -ErrorAction SilentlyContinue
        if ($existingUser){
            $samAccountName = $trySamAccountName + $i
            $upn = "$samAccountName@mydomain.com"
            $i++  
        }
    } while ($existingUser -ne $null)

    Write-Host "Creating user for $($givenName) $($surName) with SamAccountName: $samAccountName" -ForegroundColor Green

   
    # Create Users in Active Directory
    $NewUserParams = @{
        Name = "$givenName $surName"
        GivenName = $givenName
        Surname = $surName
        SamAccountName = $samAccountName
        UserPrincipalName = $upn
        AccountPassword = ($Employee.Temp_Password | ConvertTo-SecureString -AsPlainText -Force)
        Enabled = $true
        Path = $DepartmentOU_Map[$department]
        ChangePasswordAtLogon = $true
    }

    New-ADUser @NewUserParams
}