Doppelte User im AD, Konto ist bereits vorhanden

#######################
#Übergabe von Testsystem#
#######################
Param(
    $ON_Vorname = "User",  
$ON_Name = "Test",  
$ON_Location = "Düsseldorf",  
$ON_EmployeeID = "9999",  
$ON_Funktion = "Testuser",  
$ON_Dezernat = "Düsseldorf"  

    #[Parameter(Mandatory=$True)]
    #[string]$ON_Vorname,
    #[Parameter(Mandatory=$True)]
    #[string]$ON_Name,
    #[Parameter(Mandatory=$True)]
    #[string]$ON_Location,
    #[Parameter(Mandatory=$True)]
    #[string]$ON_EmployeeID,
    #[Parameter(Mandatory=$True)]
    #[string]$ON_Funktion,
    #[Parameter(Mandatory=$True)]
    #[string]$ON_Derzernat
    )


###########################
#Test-Conection LDAPServer#
###########################

$ldapServer1 = "DC01.contoso.com"  
$ldapServer2 = "DC02.contoso.com"  
$ldapServer3 = "DC03.contoso.com"  

Foreach ($Computer in $ldapserver1)
{

    if (Test-Connection -ComputerName $ldapserver1 -Count 1 -Quiet)
    {
    $Server = "DC01"  
    } 
    
        elseif (Test-Connection -ComputerName $ldapserver2 -Count 1 -Quiet)
        {  
        $Server = "DC02"  
        }
    
            elseif (Test-Connection -ComputerName $ldapserver3 -Count 1 -Quiet)
            {
            $Server = "DC03"  
            }
} 


##################
#benötigte Arrays#
##################

#Department_Array
$Department_Array = @("Düsseldorf")  

###################
#benötigte Switche#
###################

#Domain_Switch
$Domain = Switch($ON_Location) {
    'Berlin' {'@ber.contoso.com'}  
    'Chemnitz' {'@che.contoso.com'}  
    'Düsseldorf' {'@dus.contoso.com'}  
    'Frankfurt' {'@fra.contoso.com'}  
    'Hamburg' {'@ham.contoso.com'}  
    'Köln' {'@cgn.contoso.com'}  
    'München' {'@muc.contoso.com'}  
    'Stuttgart' {'@str.contoso.com}  
    }

#postalCode_Switch
$postalCode = Switch($ON_Location) {
    'Berlin' {'10719'}  
    'Chemnitz' {'09112'}  
    'Düsseldorf' {'40474'}  
    'Frankfurt' {'60313'}  
    'Hamburg' {'20354'}  
    'Köln' {'50672'}  
    'München' {'80538'}  
    'Stuttgart' {'70173'}  
    }

#State_Switch
$st = Switch($ON_Location) {
    'Berlin' {'Berlin'}  
    'Chemnitz' {'Sachsen'}  
    'Düsseldorf' {'Nordrhein-Westfalen'}  
    'Frankfurt' {'Hessen'}  
    'Hamburg' {'Hamburg'}  
    'Köln' {'Nordrhein-Westfalen'}  
    'München' {'Bayern'}  
    'Stuttgart' {'Baden-Württenberg'}  
    }

#streetAddress_Switch
$streetAddress = Switch($ON_Location) {
    'Berlin' {'32'}  
    'Chemnitz' {' 16'}  
    'Düsseldorf' {'4'}  
    'Frankfurt' {'5-7'}  
    'Hamburg' {'63'}  
    'Köln' {'13'}  
    'München' {' 48'}  
    'Stuttgart' {'45'}  
    'Zürich' {'69'}  
    }

#Stadt_Switch für Password
$ON_Location_Short = Switch($ON_Location) {
    'Berlin' {'BER'}  
    'Chemnitz' {'CHE'}  
    'Düsseldorf' {'DUS'}  
    'Frankfurt' {'FRA'}  
    'Hamburg' {'HAM'}  
    'Köln' {'CGN'}  
    'München' {'MUC'}  
    'Stuttgart' {'STR'}  
    }

#ADS-ROOT-DC Switch
$result_RA_Standort = switch ($ON_Location)
{
	"Düsseldorf" {"$Server";break}  
	"Frankfurt"  {"$Server";break}  
    "Hamburg"    {"$Server";break}  
    "Stuttgart"  {"$Server";break}  
    "Berlin"     {"$Server";break}  
    "Köln"       {"$Server";break}  
    "Chemnitz"   {"$Server";break}  
    "München"    {"$Server";break}  
}

#ADS-SUBDOMAIN-DC Switch
$result_SUB_Standort = switch ($ON_Location)
{
	"Düsseldorf" {"$Server";break}  
	"Frankfurt"  {"$Server";break}  
    "Hamburg"    {"$Server";break}  
    "Stuttgart"  {"$Server";break}  
    "Berlin"     {"$Server";break}  
    "Köln"       {"$Server";break}  
    "Chemnitz"   {"$Server";break}  
    "München"    {"$Server";break}  
}

#OU_ROOT Switch
$result_root_ou = switch ($ON_Location)
{
	"Düsseldorf" {"OU=Users,OU=IS,DC=contoso,DC=com";break}  
	"Frankfurt"  {"OU=Users,OU=IS,DC=contoso,DC=com";break}  

}
#OU_SUB Switch
$result_Sub_ou = switch ($ON_Location)
{
	"Düsseldorf" {"OU=User,OU=DUS,DC=dus,DC=contoso,DC=com";break}  
	"Frankfurt"  {"OU=User,OU=FRA,DC=fra,DC=contoso,DC=com";break}  

}


######################
#benötigte Funktionen#
######################

#Function Replace-Umlaut
Function Replace-Umlaut {

    param (
       [string]$Text 
    )
    $characterMap = @{}
    $characterMap.([Int][Char]'ä') = "ae"  
    $characterMap.([Int][Char]'ö') = "oe"  
    $characterMap.([Int][Char]'ü') = "ue"  
    $characterMap.([Int][Char]'ß') = "ss"  
    $characterMap.([Int][Char]'Ä') = "Ae"  
    $characterMap.([Int][Char]'Ü') = "Ue"  
    $characterMap.([Int][Char]'Ö') = "Oe"  
    $characterMap.([Int][Char]' ') = "."  
    $characterMap.([Int][Char]'á') = "_"  
    
    ForEach ($key in $characterMap.Keys) {
        $Text = $Text -creplace ([Char]$key),$characterMap[$key] 
    }
     $Text
}
#create User and Password Single
$count=0
$count++
$Jahr = (Get-Date).Year
$vorname = Replace-Umlaut $ON_Vorname
$nachname = Replace-Umlaut $ON_Name
$nastring1 = $("$Vorname").Substring("0","1").Tolower()  
$nastring2 =$NachName.ToLower()
$PWString = $("$Vorname").Substring("0","1").ToUpper()  
$PWString2 = $("$NachName").Substring("","1").ToUpper()  
$PWString3 = $Nachname.substring(1,1).Tolower()
$PWString4 = $ON_Location_Short.ToUpper()
$userPrincipalName1 = "$nastring1$nastring2"  
$Password = "$PWString4$Jahr$PWString$PWString2$PWString3"  
$user_password = $Password | ConvertTo-SecureString -AsPlainText -Force
$AD_Konto_Name = "$ON_Name, $ON_Vorname"  
$userPrincipalName = "$userPrincipalName1$Domain"  
$SamAccountName = "$PWString$nachname"  

#create User Double
$vorname1 = Replace-Umlaut $ON_Vorname
$nachname1 = Replace-Umlaut $ON_Name
$nastring1 = $("$Vorname1").Substring("0","1").Tolower()  
$nastring2 =$NachName1.ToLower()
$PWString1 = $("$Vorname1").Substring("0","1").ToUpper()  
$PWString2 = $("$NachName1").Substring("","1").ToUpper()  
$PWString3 = $Nachname1.substring(1,1).Tolower()
$PWString4 = $ON_Location_Short.ToUpper()
$userPrincipalName2 = "$nastring1$nastring2$count"  
$count=0
$count++
$AD_Konto_Name_Double = "$ON_Name, $ON_Vorname$count"  
$userPrincipalName_Double = "$userPrincipalName1$Count$Domain"  
$SamAccountName_Double = "$PWString1$nachname1$count"  


#######################
#Settings_User for All#
#######################
$Settings_User = @{

    GivenName = $ON_Vorname
    SN = $ON_Name
    Company = "Testfirma"   
    streetAddress = $streetAddress
    postalCode = $postalCode
    l = $ON_Location
    st = $st
    c = "DE"  
    co = "Deutschland"  
    countryCode = "276"  
    EmployeeID = $ON_EmployeeID
    title = $ON_Funktion
    Department = $ON_Dezernat 
}

##################################
#Settings_User_Single_DC_for Root#
##################################
$Root_Ad_User_Single = @{
    name = "$AD_Konto_Name"  
    Displayname = $AD_Konto_Name 
    userPrincipalName = "$userPrincipalName1@contoso.com"  
    SamAccountName = "$SamAccountName"  
    Path   = $result_root_ou
    Server = $result_RA_Standort
    OtherAttributes = $Settings_User
}

##################################
#Settings_User_Single_DC_for Sub#
##################################
$Sub_Ad_User_Single = @{
    name = "$AD_Konto_Name"  
    Displayname = $AD_Konto_Name 
    userPrincipalName = "$userPrincipalName"  
    SamAccountName = "$SamAccountName"  
    Path   = $result_Sub_ou
    Server = $result_Sub_Standort
    OtherAttributes = $Settings_User
}


##################################
#Settings_User_Double_DC_for Root#
##################################
$Root_Ad_User_Double = @{
    name = "$AD_Konto_Name_Double"  
    Displayname = "$ON_Name,  $ON_Vorname"   
    userPrincipalName = "$userPrincipalName2@contoso.com"  
    SamAccountName = "$SamAccountName_Double"  
    Path   = $result_root_ou
    Server = $result_RA_Standort
    OtherAttributes = $Settings_User
}

#################################
#Settings_User_Double_DC_for Sub#
#################################
$Sub_Ad_User_Double = @{
    name = "$AD_Konto_Name_Double"  
    Displayname = "$ON_Name,  $ON_Vorname"   
    userPrincipalName = "$userPrincipalName_Double"  
    SamAccountName = "$SamAccountName_Double"  
    Path   = $result_Sub_ou
    Server = $result_Sub_Standort
    OtherAttributes = $Settings_User
}

####################
#Funktionen AD_User#
####################

#function IT_UserAD
function IT_UserAD{
new-aduser  @Root_Ad_User_Single -ErrorAction Stop -AccountPassword $user_password -ChangePasswordAtLogon $true -Enabled $true
}
#function UserAD
function UserAD{
new-aduser  @Sub_Ad_User_Single -ErrorAction Stop -AccountPassword $user_password -ChangePasswordAtLogon $true -Enabled $true
}
#function Double_UserAD
function Double_IT_UserAD{
new-aduser  @Root_Ad_User_Double -ErrorAction Stop -AccountPassword $user_password -ChangePasswordAtLogon $true -Enabled $true
}
#function Double_IT_UserAD
function Double_UserAD{
new-aduser  @Sub_Ad_User_Double -ErrorAction Stop -AccountPassword $user_password -ChangePasswordAtLogon $true -Enabled $true
}
#function Add_User
function Add_User {
if ($ON_Dezernat -in $Department_Array)
{
    IT_UserAD
}
else 
{ 
    UserAD 
}}
#function Double_Add_User
function Double_Add_User {
if ($ON_Dezernat -in $Department_Array)
{

    Double_IT_UserAD |Out-Null
}
else 
{ 

    Double_UserAD |Out-Null
}}


#Get-User-Name
function Get-User {
    [CmdletBinding()]
param(
        [Parameter(Mandatory=$true, ParameterSetName="Name")]  
        [ValidateNotNullOrEmpty()]
        [string]$Name,
                # UPN we will be searching in the domains; this is mandatory.
        [Parameter(Mandatory=$true, ParameterSetName="UserPrincipalName")]  
        [ValidateNotNullOrEmpty()]
        [string]$UserPrincipalName
    )

    process {
        $Domain_Array = @($server)

switch ($PSCmdlet.ParameterSetName) {
            Name {
                $SearchCriteria = "Name"  
                $SearchSpace = $AD_Konto_Name
            }

            UserPrincipalName {
                $SearchCriteria = "UserPrincipalName"  
                $SearchSpace = $UserPrincipalName
            }

        }

        foreach ($DCdomain in $Domain_Array) {
            $SearchResult = Get-ADUser -Filter {$SearchCriteria -eq $SearchSpace} -Server $DCdomain
        
           
            if ($SearchResult) {
                $Output = Get-ADUser -Identity $SearchResult.SamAccountName -Server $DCdomain

            Double_Add_User
                
            }
        }

        
        if ($Output -eq $null) {
             #ping $DCdomain
             Add_User
        }
    }
}


Get-User -name $AD_Konto_Name