Public/Classroom/Get-GSCourse.ps1

function Get-GSCourse {
    <#
    .SYNOPSIS
    Gets a classroom course or list of courses

    .DESCRIPTION
    Gets a classroom course or list of courses

    .PARAMETER Id
    Identifier of the course to return. This identifier can be either the Classroom-assigned identifier or an alias.

    If excluded, returns the list of courses.

    .PARAMETER User
    The user to request course information as

    .PARAMETER Teacher
    Restricts returned courses to those having a teacher with the specified identifier. The identifier can be one of the following:

    * the numeric identifier for the user
    * the email address of the user
    * the string literal "me", indicating the requesting user

    .PARAMETER Student
    Restricts returned courses to those having a student with the specified identifier. The identifier can be one of the following:

    * the numeric identifier for the user
    * the email address of the user
    * the string literal "me", indicating the requesting user

    .PARAMETER CourseStates
    Restricts returned courses to those in one of the specified states.

    .EXAMPLE
    Get-GSCourse -Teacher aristotle@athens.edu
    #>

    [cmdletbinding(DefaultParameterSetName = "List")]
    Param
    (
        [parameter(Mandatory = $false,Position = 0,ParameterSetName = "Get")]
        [ValidateNotNullOrEmpty()]
        [String[]]
        $Id,
        [parameter(Mandatory = $false)]
        [String]
        $User = $Script:PSGSuite.AdminEmail,
        [parameter(Mandatory = $false,ParameterSetName = "List")]
        [String]
        $Teacher,
        [parameter(Mandatory = $false,ParameterSetName = "List")]
        [String]
        $Student,
        [parameter(Mandatory = $false,ParameterSetName = "List")]
        [Google.Apis.Classroom.v1.CoursesResource+ListRequest+CourseStatesEnum[]]
        $CourseStates
    )
    Begin {
        $serviceParams = @{
            Scope       = 'https://www.googleapis.com/auth/classroom.courses'
            ServiceType = 'Google.Apis.Classroom.v1.ClassroomService'
            User        = $User
        }
        $service = New-GoogleService @serviceParams
    }
    Process {
        if ($PSBoundParameters.Keys -contains 'Id') {
            foreach ($I in $Id) {
                try {
                    Write-Verbose "Getting Course '$Id'"
                    $request = $service.Courses.Get($Id)
                    $request.Execute()
                }
                catch {
                    if ($ErrorActionPreference -eq 'Stop') {
                        $PSCmdlet.ThrowTerminatingError($_)
                    }
                    else {
                        Write-Error $_
                    }
                }
            }
        }
        else {
            try {
                Write-Verbose "Getting Course List"
                $request = $service.Courses.List()
                foreach ($s in $CourseStates) {
                    $request.CourseStates += $s
                }
                if ($PSBoundParameters.Keys -contains 'Student') {
                    $request.StudentId = $PSBoundParameters['Student']
                }
                if ($PSBoundParameters.Keys -contains 'Teacher') {
                    $request.TeacherId = $PSBoundParameters['Teacher']
                }
                [int]$i = 1
                do {
                    $result = $request.Execute()
                    if ($null -ne $result.Courses) {
                        $result.Courses
                    }
                    $request.PageToken = $result.NextPageToken
                    [int]$retrieved = ($i + $result.Courses.Count) - 1
                    Write-Verbose "Retrieved $retrieved Courses..."
                    [int]$i = $i + $result.Courses.Count
                }
                until (!$result.NextPageToken)
            }
            catch {
                if ($ErrorActionPreference -eq 'Stop') {
                    $PSCmdlet.ThrowTerminatingError($_)
                }
                else {
                    Write-Error $_
                }
            }
        }
    }
}