DSCResources/MSFT_AADCrossTenantAccessPolicy/MSFT_AADCrossTenantAccessPolicy.psm1

function Get-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        [ValidateSet('Yes')]
        $IsSingleInstance,

        [Parameter()]
        [System.String]
        $DisplayName,

        [Parameter()]
        [ValidateSet('microsoftonline.com', 'microsoftonline.us', 'partner.microsoftonline.cn')]
        [System.String[]]
        $AllowedCloudEndpoints,

        [Parameter()]
        [System.String]
        [ValidateSet('Present')]
        $Ensure = 'Present',

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $Credential,

        [Parameter()]
        [System.String]
        $ApplicationId,

        [Parameter()]
        [System.String]
        $TenantId,

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $ApplicationSecret,

        [Parameter()]
        [System.String]
        $CertificateThumbprint,

        [Parameter()]
        [Switch]
        $ManagedIdentity
    )

    try
    {
        $ConnectionMode = New-M365DSCConnection -Workload 'MicrosoftGraph' `
            -InboundParameters $PSBoundParameters

        #Ensure the proper dependencies are installed in the current environment.
        Confirm-M365DSCDependencies

        #region Telemetry
        $ResourceName = $MyInvocation.MyCommand.ModuleName.Replace('MSFT_', '')
        $CommandName = $MyInvocation.MyCommand
        $data = Format-M365DSCTelemetryParameters -ResourceName $ResourceName `
            -CommandName $CommandName `
            -Parameters $PSBoundParameters
        Add-M365DSCTelemetryEvent -Data $data
        #endregion

        $nullResult = $PSBoundParameters
        $nullResult.Ensure = 'Absent'

        $getValue = Get-MgBetaPolicyCrossTenantAccessPolicy -ErrorAction SilentlyContinue

        if ($null -eq $getValue)
        {
            Write-Verbose -Message "Could not find an Azure AD Cross Tenant Access Policy with name {$DisplayName}"
            return $nullResult
        }

        $results = @{
            IsSingleInstance      = 'Yes'
            DisplayName           = $getValue.DisplayName
            AllowedCloudEndpoints = $getValue.AllowedCloudEndpoints
            Ensure                = 'Present'
            Credential            = $Credential
            ApplicationId         = $ApplicationId
            TenantId              = $TenantId
            ApplicationSecret     = $ApplicationSecret
            CertificateThumbprint = $CertificateThumbprint
            ManagedIdentity       = $ManagedIdentity.IsPresent
        }

        return [System.Collections.Hashtable] $results
    }
    catch
    {
        New-M365DSCLogEntry -Message 'Error retrieving data:' `
            -Exception $_ `
            -Source $($MyInvocation.MyCommand.Source) `
            -TenantId $TenantId `
            -Credential $Credential

        return $nullResult
    }
}

function Set-TargetResource
{
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        [ValidateSet('Yes')]
        $IsSingleInstance,

        [Parameter()]
        [System.String]
        $DisplayName,

        [Parameter()]
        [ValidateSet('microsoftonline.com', 'microsoftonline.us', 'partner.microsoftonline.cn')]
        [System.String[]]
        $AllowedCloudEndpoints,

        [Parameter()]
        [System.String]
        [ValidateSet('Present')]
        $Ensure = 'Present',

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $Credential,

        [Parameter()]
        [System.String]
        $ApplicationId,

        [Parameter()]
        [System.String]
        $TenantId,

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $ApplicationSecret,

        [Parameter()]
        [System.String]
        $CertificateThumbprint,

        [Parameter()]
        [Switch]
        $ManagedIdentity
    )

    #Ensure the proper dependencies are installed in the current environment.
    Confirm-M365DSCDependencies

    #region Telemetry
    $ResourceName = $MyInvocation.MyCommand.ModuleName.Replace('MSFT_', '')
    $CommandName = $MyInvocation.MyCommand
    $data = Format-M365DSCTelemetryParameters -ResourceName $ResourceName `
        -CommandName $CommandName `
        -Parameters $PSBoundParameters
    Add-M365DSCTelemetryEvent -Data $data
    #endregion

    $currentInstance = Get-TargetResource @PSBoundParameters

    if ($Ensure -eq 'Present' -and $currentInstance.Ensure -eq 'Absent')
    {
        Write-Verbose -Message "Azure AD Cross Tenant Access Policy instance cannot be created"
    }
    elseif ($Ensure -eq 'Present' -and $currentInstance.Ensure -eq 'Present')
    {
        Write-Verbose -Message "Updating the Azure AD Cross Tenant Access Policy"
        $UpdateParams = @{}
        if (-not [System.String]::IsNullOrEmpty($DisplayName))
        {
            $UpdateParams.Add("DisplayName", $DisplayName)
        }
        if ($null -ne $AllowedCloudEndpoints)
        {
            $UpdateParams.Add("AllowedCloudEndpoints", $AllowedCloudEndpoints)
        }
        Update-MgBetaPolicyCrossTenantAccessPolicy -BodyParameter $UpdateParams
    }
    elseif ($Ensure -eq 'Absent' -and $currentInstance.Ensure -eq 'Present')
    {
        Write-Verbose -Message "Azure AD Cross Tenant Access Policies cannot be removed."
    }
}

function Test-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.String]
        [ValidateSet('Yes')]
        $IsSingleInstance,

        [Parameter()]
        [System.String]
        $DisplayName,

        [Parameter()]
        [ValidateSet('microsoftonline.com', 'microsoftonline.us', 'partner.microsoftonline.cn')]
        [System.String[]]
        $AllowedCloudEndpoints,

        [Parameter()]
        [System.String]
        [ValidateSet('Present')]
        $Ensure = 'Present',

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $Credential,

        [Parameter()]
        [System.String]
        $ApplicationId,

        [Parameter()]
        [System.String]
        $TenantId,

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $ApplicationSecret,

        [Parameter()]
        [System.String]
        $CertificateThumbprint,

        [Parameter()]
        [Switch]
        $ManagedIdentity
    )

    #Ensure the proper dependencies are installed in the current environment.
    Confirm-M365DSCDependencies

    #region Telemetry
    $ResourceName = $MyInvocation.MyCommand.ModuleName.Replace('MSFT_', '')
    $CommandName = $MyInvocation.MyCommand
    $data = Format-M365DSCTelemetryParameters -ResourceName $ResourceName `
        -CommandName $CommandName `
        -Parameters $PSBoundParameters
    Add-M365DSCTelemetryEvent -Data $data
    #endregion

    Write-Verbose -Message "Testing configuration of the Azure AD Cross Tenant Access Policy with name [$DisplayName]"

    $CurrentValues = Get-TargetResource @PSBoundParameters
    $ValuesToCheck = ([Hashtable]$PSBoundParameters).clone()

    if ($CurrentValues.Ensure -ne $Ensure)
    {
        Write-Verbose -Message "Test-TargetResource returned $false"
        return $false
    }

    Write-Verbose -Message "Current Values: $(Convert-M365DscHashtableToString -Hashtable $CurrentValues)"
    Write-Verbose -Message "Target Values: $(Convert-M365DscHashtableToString -Hashtable $ValuesToCheck)"

    $testResult = Test-M365DSCParameterState -CurrentValues $CurrentValues `
        -Source $($MyInvocation.MyCommand.Source) `
        -DesiredValues $PSBoundParameters `
        -ValuesToCheck $ValuesToCheck.Keys

    Write-Verbose -Message "Test-TargetResource returned $testResult"

    return $testResult
}

function Export-TargetResource
{
    [CmdletBinding()]
    [OutputType([System.String])]
    param
    (
        [Parameter()]
        [System.Management.Automation.PSCredential]
        $Credential,

        [Parameter()]
        [System.String]
        $ApplicationId,

        [Parameter()]
        [System.String]
        $TenantId,

        [Parameter()]
        [System.Management.Automation.PSCredential]
        $ApplicationSecret,

        [Parameter()]
        [System.String]
        $CertificateThumbprint,

        [Parameter()]
        [Switch]
        $ManagedIdentity
    )

    $ConnectionMode = New-M365DSCConnection -Workload 'MicrosoftGraph' `
        -InboundParameters $PSBoundParameters

    #Ensure the proper dependencies are installed in the current environment.
    Confirm-M365DSCDependencies

    #region Telemetry
    $ResourceName = $MyInvocation.MyCommand.ModuleName.Replace('MSFT_', '')
    $CommandName = $MyInvocation.MyCommand
    $data = Format-M365DSCTelemetryParameters -ResourceName $ResourceName `
        -CommandName $CommandName `
        -Parameters $PSBoundParameters
    Add-M365DSCTelemetryEvent -Data $data
    #endregion

    try
    {
        $dscContent = ''
        $params = @{
            IsSingleInstance      = 'Yes'
            Ensure                = 'Present'
            Credential            = $Credential
            ApplicationId         = $ApplicationId
            TenantId              = $TenantId
            ApplicationSecret     = $ApplicationSecret
            CertificateThumbprint = $CertificateThumbprint
            Managedidentity       = $ManagedIdentity.IsPresent
        }

        $Results = Get-TargetResource @Params
        $Results = Update-M365DSCExportAuthenticationResults -ConnectionMode $ConnectionMode `
            -Results $Results

        $currentDSCBlock = Get-M365DSCExportContentForResource -ResourceName $ResourceName `
            -ConnectionMode $ConnectionMode `
            -ModulePath $PSScriptRoot `
            -Results $Results `
            -Credential $Credential

        $dscContent += $currentDSCBlock
        Save-M365DSCPartialExport -Content $currentDSCBlock `
            -FileName $Global:PartialExportFileName
        $i++
        Write-Host $Global:M365DSCEmojiGreenCheckMark
        return $dscContent
    }
    catch
    {
        Write-Host $Global:M365DSCEmojiRedX

        New-M365DSCLogEntry -Message 'Error during Export:' `
            -Exception $_ `
            -Source $($MyInvocation.MyCommand.Source) `
            -TenantId $TenantId `
            -Credential $Credential

        return ''
    }
}

Export-ModuleMember -Function *-TargetResource