Functions/Connect-PartnerCenterAdminAccount.ps1

<#
.SYNOPSIS
    This function connects to Partner Center using admin account credentials or a MSPComplete Endpoint.
.DESCRIPTION
    This function connects to Partner Center using admin account credentials or a MSPComplete Endpoint.
    It returns whether the connection and logon was successful.
.EXAMPLE
    Connect-PartnerCenterAdminAccount -Endpoint $Endpoint
.EXAMPLE
    $Endpoint | Connect-PartnerCenterAdminAccount
.EXAMPLE
    Connect-PartnerCenterAdminAccount -Username $username -Password $password -ApplicationId $applicationId
#>

function Connect-PartnerCenterAdminAccount {
    [CmdletBinding(PositionalBinding=$false)]
    [OutputType([Bool])]
    param (
        # The username of the Partner Center admin account.
        [Parameter(Mandatory=$true, ParameterSetName="credential")]
        [String]$username,

        # The password of the Partner Center admin account.
        [Parameter(Mandatory=$true, ParameterSetName="credential")]
        [SecureString]$password,

        # The Partner Center Native App Application Id
        [Parameter(Mandatory=$true, ParameterSetName="credential")]
        [GUID]$applicationId,

        # The MSPComplete Endpoint for the Partner Center admin credentials.
        [Parameter(Mandatory=$true, ParameterSetName="endpoint", ValueFromPipeline=$true)]
        $endpoint
    )

    # If given endpoint, retrieve credential directly
    if ($PSCmdlet.ParameterSetName -eq "endpoint") {
        $partnerCenterCredential = $endpoint | Get-CredentialFromMSPCompleteEndpoint
        $username = $partnerCenterCredential.Username

        # Check if endpoint has application ID extended property
        if (!($endpoint.ExtendedProperties) -or !(Search-HashTable -HashTable $endpoint.ExtendedProperties -Key "ApplicationId")) {
            Write-Error "Endpoint provided does not have an 'ApplicationId' extended property."
            return $false
        }
        $applicationId = $endpoint.ExtendedProperties.ApplicationId
    }

    # Create the Partner Center credential from the given username and password
    else {
        $partnerCenterCredential = [PSCredential]::new($username, $password)
    }

    # Logon to Partner Center
    try {
        Connect-PartnerCenter -ApplicationId $applicationId -Credential $partnerCenterCredential -ErrorAction Stop

        # Logon was successful
        Write-Information "Connection and logon to Partner Center successful with username '$($username)'."
        return $true
    }

    # Error while attempting to logon
    catch {
        Write-Error "Exception while attempting to logon to Partner Center account with username '$($username)'.`r`n$($_.Exception.Message)"
        return $false
    }
}