function Connect-EXOnline
{
 
    $credentials = Get-Credential
    Write-Output "Getting the Exchange Online cmdlets"
 
    $Session = New-PSSession -ConnectionUri https://outlook.office365.com/powershell-liveid/ `
    -ConfigurationName Microsoft.Exchange -Credential $credentials `
    -Authentication Basic -AllowRedirection
    Import-PSSession $Session
 
}

function Show-Menu
{
     param (
           [string]$Title = "GCITS Distribution Group Editor"
     )
     cls
     Write-Host "================ $Title ================"
     
     Write-Host "1: Press '1' to connect to Exchange Online. (Do this first)"
     Write-Host "2: Press '2' to add a single contact to a distribution group."
     Write-Host "3: Press '3' to get a list of distribution groups."
     Write-Host "4: Press '4' to create a distribution group."
     Write-Host "5: Press '5' to get a list of distribution group members."
     Write-Host "6: Press '6' to remove a contact."
     Write-Host "Q: Press 'Q' to quit."
}

function AddSingleToGroup
{
    $name = Read-Host "Please enter the name of the external user"
    $email = Read-Host "Please enter the email of the external user"
    Write-Host "Current distribution Groups:"
    Get-DistributionGroup | ft Name, Identity
    $distributiongroup = Read-Host "Please enter the group name that you would like to add the user to"
    New-MailContact -Name $name -ExternalEmailAddress $email
    Add-DistributionGroupMember -Identity $distributiongroup -Member $email
}

function RemoveContact
{
    $email = Read-Host "Please enter the email of the contact to remove"
    Write-Host "Removing Contact..."
    Remove-MailContact -identity $email
}

function CreateGroup
{
    $groupName = Read-Host "Please enter the name of the distribution group"
    New-DistributionGroup -Name "$groupName"
}

function GetMembers
{
    Write-Host "Current distribution Groups:"
    Get-DistributionGroup | ft Name, Identity
    $groupName = Read-Host "Please enter the name of the relevant distribution group"
    Get-DistributionGroupMember -Identity "$groupName" | ft Name, PrimarySMTPAddress
}


do
{
     Show-Menu
     $input = Read-Host "Please make a selection"
     switch ($input)
     {
           '1' {
                cls
                Connect-EXOnline
           } '2' {
                cls
                AddSingleToGroup
           } '3' {
                cls
                Get-DistributionGroup | ft Name, Identity
           } '4' {
                cls
                CreateGroup
           } '5' {
                cls
                GetMembers
           } '6' {
                cls
                RemoveContact
           }'q' {
                return
           }
     }
     pause
}
until ($input -eq 'q')