WVD Send Message to User Session

<#
.SYNOPSIS
    Send a Message to a WVD 2020 Spring Release User Session.
.DESCRIPTION
    Send a Message to a WVD 2020 Spring Release User Session, using the new Az.Desktopvirtualization PowerShell Module and WVD ARM Architecture (2020 Spring Release).
.EXAMPLE
    Invoke-WVDSendMessageToUserSession 
.CONTEXT
    Windows Virtual Desktops
.MODIFICATION_HISTORY
    Esther Barthel, MSc - 13/06/20 - Original code
    Esther Barthel, MSc - 13/06/20 - Standardizing script, based on the ControlUp Scripting Standards (version 0.2)
.LINK
    https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/import-clixml?view=powershell-7
.COMPONENT
    Set-AzSPCredentials - The required Azure Service Principal (Subcription level) and tenantID information need to be securely stored in a Credentials File. The Set-AzSPCredentials Script Action will ensure the file is created according to ControlUp standards
    Az.Desktopvirtualization PowerShell Module - The Az.Desktopvirtualization PowerShell Module must be installed on the machine running this Script Action
.NOTES
    Version:        0.1
    Author:         Esther Barthel, MSc
    Creation Date:  2020-06-13
    Updated:        2020-06-13
                    Standardized the function, based on the ControlUp Standards (v0.2)
    Purpose:        Script Action, created for ControlUp WVD Monitoring
        
    Copyright (c) cognition IT. All rights reserved.
#>
[CmdletBinding()]
Param
(
    [Parameter(
        Position=0, 
        Mandatory=$true, 
        HelpMessage='Enter the User of an active WVD Session'
    )]
    [string] $User, 

    [Parameter(
        Position=1, 
        Mandatory=$true, 
        HelpMessage='Enter the message body'
    )]
    [string] $Message 
)    

# dot sourcing WVD Functions
[string]$mainformXAML = @'
<Window x_Class="wvdSP_Input_Form.MainWindow"
        
        xmlns_x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns_d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns_mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns_local="clr-namespace:Esther_s_Input_Form"
        mc_Ignorable="d"
        Title="Enter the WVD Service Principal (SP) details" Height="389.336" Width="617.103">
    <Grid>
        <TextBox x_Name="textboxTenantId" HorizontalAlignment="Left" Height="31" Margin="176,50,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="398"/>
        <Label Content="SP Tenant ID" HorizontalAlignment="Left" Height="30" Margin="29,51,0,0" VerticalAlignment="Top" Width="117"/>
        <TextBox x_Name="textboxAppId" HorizontalAlignment="Left" Height="30" Margin="176,118,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="398"/>
        <Label Content="SP App ID" HorizontalAlignment="Left" Height="30" Margin="29,118,0,0" VerticalAlignment="Top" Width="117"/>
        <PasswordBox x_Name="textboxAppSecret" HorizontalAlignment="Left" Height="31" Margin="176,192,0,0" VerticalAlignment="Top" Width="398"/>
        <Label Content="SP App Secret" HorizontalAlignment="Left" Height="30" Margin="29,193,0,0" VerticalAlignment="Top" Width="117"/>
        <Button x_Name="buttonOK" Content="OK" HorizontalAlignment="Left" Height="46" Margin="29,274,0,0" VerticalAlignment="Top" Width="175" IsDefault="True"/>
        <Button x_Name="buttonCancel" Content="Cancel" HorizontalAlignment="Left" Height="46" Margin="244,274,0,0" VerticalAlignment="Top" Width="175" IsDefault="True"/>

    </Grid>
</Window>
'@

Function Invoke-WVDSPCredentialsForm {
# Created by Guy Leech - @guyrleech 17/05/2020
    Param
    (
        [Parameter(Mandatory=$true)]
        $inputXaml
    )

    $form = $null
    $inputXML = $inputXaml -replace 'mc:Ignorable="d"' , '' -replace 'x:N' ,'N'  -replace '^<Win.*' , '<Window'
    [xml]$xaml = $inputXML

    if( $xaml )
    {
        $reader = New-Object -TypeName Xml.XmlNodeReader -ArgumentList $xaml

        try
        {
            $form = [Windows.Markup.XamlReader]::Load( $reader )
        }
        catch
        {
            Throw "Unable to load Windows.Markup.XamlReader. Double-check syntax and ensure .NET is installed.`n$_"
        }

        $xaml.SelectNodes( '//*[@Name]' ) | ForEach-Object `
        {
            Set-Variable -Name "WPF$($_.Name)" -Value $Form.FindName($_.Name) -Scope Global
        }
    }
    else
    {
        Throw "Failed to convert input XAML to WPF XML"
    }

    $form
}

function Get-AzSPStoredCredentials {
    <#
    .SYNOPSIS
        Retrieve the Azure Service Principal Stored Credentials.
    .DESCRIPTION
        Retrieve the Azure Service Principal Stored Credentials from a stored credentials file.
    .EXAMPLE
        Get-AzSPStoredCredentials
    .CONTEXT
        Azure
    .MODIFICATION_HISTORY
        Esther Barthel, MSc - 03/03/20 - Original code
        Esther Barthel, MSc - 03/03/20 - Standardizing script, based on the ControlUp Scripting Standards (version 0.2)
    .COMPONENT
        Import-Clixml - https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/import-clixml?view=powershell-5.1
    .NOTES
        Version:        0.1
        Author:         Esther Barthel, MSc
        Creation Date:  2020-03-03
        Updated:        2020-03-03
                        Standardized the function, based on the ControlUp Standards (v0.2)
        Updated:        2020-05-08
                        Created a separate Azure Credentials function to support ARM architecture and Az PowerShell Module scripted actions
        Purpose:        Script Action, created for ControlUp WVD Monitoring
        
        Copyright (c) cognition IT. All rights reserved.
    #>
    [CmdletBinding()]
    Param()

    #region function settings
        # Stored Credentials XML file
        $System = "AZ"
        $strAzSPCredFolder = "$([environment]::GetFolderPath('CommonApplicationData'))ControlUpScriptSupport"
        $AzSPCredentials = $null
    #endregion

    Write-Verbose ""
    Write-Verbose "----------------------------- "
    Write-Verbose "| Get Azure SP Credentials: | "
    Write-Verbose "----------------------------- "
    Write-Verbose ""

    If (Test-Path -Path "$($strAzSPCredFolder)$($env:USERNAME)_$($System)_Cred.xml")
    {
        try 
        {
            $AzSPCredentials = Import-Clixml -Path "$strAzSPCredFolder$($env:USERNAME)_$($System)_Cred.xml"
        }
        catch 
        {
            Write-Error ("The required PSCredential object could not be loaded. " + $_)
        }
    }
    Else
    {
        Write-Error "The Azure Service Principal Credentials file stored for this user ($($env:USERNAME)) cannot be found. `nCreate the file with the Set-AzSPCredentials script action (prerequisite)."
        Exit
    }
    return $AzSPCredentials
}

function Set-AzSPStoredCredentials {
    <#
    .SYNOPSIS
        Store the Azure Service Principal Credentials.
    .DESCRIPTION
        Store the Azure Service Principal Credentials to an encrypted stored credentials file.
    .EXAMPLE
        Set-AzSPStoredCredentials
    .CONTEXT
        Azure
    .MODIFICATION_HISTORY
        Esther Barthel, MSc - 22/03/20 - Original code
        Esther Barthel, MSc - 22/03/20 - Standardizing script, based on the ControlUp Scripting Standards (version 0.2)
    .COMPONENT
        Export-Clixml - https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/export-clixml?view=powershell-5.1
    .NOTES
        Version:        0.1
        Author:         Esther Barthel, MSc
        Creation Date:  2020-03-22
        Updated:        2020-03-22
                        Standardized the function, based on the ControlUp Standards (v0.2)
        Updated:        2020-05-08
                        Created a separate Azure Credentials function to support ARM architecture and Az PowerShell Module scripted actions
        Purpose:        Script Action, created for ControlUp WVD Monitoring
        
        Copyright (c) cognition IT. All rights reserved.
    #>
    [CmdletBinding()]
    Param(
    )

    #region function settings
        # Stored Credentials XML file
        $System = "AZ"
        $strAzSPCredFolder = "$([environment]::GetFolderPath('CommonApplicationData'))ControlUpScriptSupport"
        $AzSPCredentials = $null
    #endregion

    Write-Verbose ""
    Write-Verbose "------------------------------- "
    Write-Verbose "| Store Azure SP Credentials: | "
    Write-Verbose "------------------------------- "
    Write-Verbose ""

    If (!(Test-Path -Path "$($strAzSPCredFolder)"))
    {
        New-Item -ItemType Directory -Path "$($strAzSPCredFolder)"
        Write-Verbose "* AzSPCredentials: Path $($strAzSPCredFolder) created"
    }
    try 
    {
        Add-Type -AssemblyName PresentationFramework
        # Show the Form that will ask for the WVD Service Principal information (tenant ID, App ID, & App Secret)
        if( $mainForm = Invoke-WVDSPCredentialsForm -inputXaml $mainformXAML )
        {
            $WPFbuttonOK.Add_Click( {
                $_.Handled = $true
                $mainForm.DialogResult = $true
                $mainForm.Close()
            })
        
            $WPFbuttonCancel.Add_Click( {
                $_.Handled = $true
                $mainForm.DialogResult = $false
                $mainForm.Close()
            })
        
            $null = $WPFtextboxTenantId.Focus()
        
            if( $mainForm.ShowDialog() )
            {
                # Retrieve the form input (and check for errors)
                # tenant ID
                If ([string]::IsNullOrEmpty($($WPFtextboxTenantId.Text)))
                {
                    Write-Error "The provided tenant ID is empty!"
                    Exit
                }
                else 
                {
                    $tenantID = $($WPFtextboxTenantId.Text)
                }
                # app ID
                If ([string]::IsNullOrEmpty($($WPFtextboxAppId.Text)))
                {
                    Write-Error "The provided app ID is empty!"
                    Exit
                }
                else 
                {
                    $appID = $($WPFtextboxAppId.Text)
                }
                # app Secret
                If ([string]::IsNullOrEmpty($($WPFtextboxAppSecret.Password)))
                {
                    Write-Error "The provided app Secret is empty!"
                    Exit
                }
                else 
                {
                    $appSecret = $($WPFtextboxAppSecret.Password)
                }

                
                $appSecret = $($WPFtextboxAppSecret.Password)
        
                #Write-Output -InputObject "Tenant id is $($tenantID)"
                #Write-Output -InputObject "App id is $($appID)"
                #Write-Output -InputObject "App secret is $($appSecret)"
            }
            else 
            {
                Write-Error "The required tenant ID, app ID and app Secret could not be retrieved from the form."
                Break
            }
        }
    }
    catch
    {
        Write-Error ("The required information could not be retrieved from the input form. " + $_)
        Exit        
    }
        # Create the SP Credentials, so they are encrypted before being stored in the XML file
        $secureAppSecret = ConvertTo-SecureString -String $appSecret -AsPlainText -Force
        $spCreds = New-Object System.Management.Automation.PSCredential($appID, $secureAppSecret)

    try
    {
        $hashAzSPCredentials = @{
            'tenantID' = $tenantID
            'spCreds' = $spCreds
        }
        $AzSPCredentials = Export-Clixml -Path "$strAzSPCredFolder$($env:USERNAME)_$($System)_Cred.xml" -InputObject $hashAzSPCredentials -Force
    }
    catch 
    {
        Write-Error ("The required PSCredential object could not be exported. " + $_)
        Exit
    }
    Write-Verbose "* AzSPCredentials: Exported succesfully."
    return $hashAzSPCredentials
}

function Invoke-CheckInstallAndImportPSModulePrereq() {
    <#
    .SYNOPSIS
        Check, Install (if allowed) and Import the given PSModule prerequisite.
    .DESCRIPTION
        Check, Install (if allowed) and Import the given PSModule prerequisite.
    .EXAMPLE
        Invoke-CheckInstallAndImportPSModulePrereq -ModuleName Az.DesktopVirtualization
    .CONTEXT
        Windows Virtual Desktops
    .MODIFICATION_HISTORY
        Esther Barthel, MSc - 23/03/20 - Original code
        Esther Barthel, MSc - 23/03/20 - Standardizing script, based on the ControlUp Scripting Standards (version 0.2)
    .COMPONENT
    .NOTES
        Version:        1.0
        Author:         Esther Barthel, MSc
        Creation Date:  2020-03-23
        Updated:        2020-03-23
                        Standardized the function, based on the ControlUp Standards (v0.2)
        Updated:        2020-07-22
                        Added an extra check to the Invoke-CheckInstallAndImportPSModuleRepreq function for the required NuGet packageprovider. If minimumversion 2.8.5.201 is not found it will install the NuGet PackageProvider
        Purpose:        Script Action, created for ControlUp WVD Monitoring
        
        Copyright (c) cognition IT. All rights reserved.
    #>
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the PowerShell Module name that needs to be installed and imported'
        )]
        [ValidateNotNullOrEmpty()]
        [string] $ModuleName
    )

    #region Check if the given PowerShell Module is installed (and if not, install it with elevated right)
        # Check if the Module is loaded
        If (-not((Get-Module -Name $($ModuleName)).Name))
        # Module is not loaded
        {
            Write-Verbose "* CheckAndInstallPSModulePrereq: PowerShell Module $($ModuleName) is not loaded in current session"
            # Check if the Module is installed
            If (-not((Get-Module -Name $($ModuleName) -ListAvailable).Name))
            # Module is not installed on the system
            {
                # Check if session is evelated
                [bool]$isElevated = (New-Object Security.Principal.WindowsPrincipal([Security.Principal.WindowsIdentity]::GetCurrent())).IsInRole([Security.Principal.WindowsBuiltInRole]::Administrator)
                if ($isElevated)
                {
                    Write-Host ("The PowerShell Module $($ModuleName) is installed from an elevated session, Scope is set to AllUsers.") -ForegroundColor Yellow
                    $psScope = "AllUsers"
                }
                else
                {
                    Write-Warning "The PowerShell Module $($ModuleName) is NOT installed from an elevated session, Scope is set to CurrentUser."
                    $psScope = "CurrentUser"
                }

                # Check the version of the installed NuGet Provider and install if the version is lower than 2.8.5.201 or the provider is missing
                try
                {
                    If (!(([string](Get-PackageProvider -Name NuGet -ListAvailable -ErrorAction SilentlyContinue).Version) -ge "2.8.5.201"))
                    {
                        Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Scope $psScope -Force -Confirm:$false -WarningAction SilentlyContinue 
                    }
                }
                catch
                {
                    Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
                    Exit
                }
                Write-Verbose "* CheckAndInstallPSModulePrereq: The prerequired NuGet PackageProvider is installed."

                # Install the Module from the PSGallery
                try
                {
                    # Install the Module from the PSGallery
                    Write-Verbose "* CheckAndInstallPSModulePrereq: Installing the $($ModuleName) PowerShell Module from the PSGallery."
                    PowerShellGetInstall-Module -Name $($ModuleName) -Confirm:$false -Force -AllowClobber -Scope $psScope -WarningAction SilentlyContinue
                }
                catch
                {
                    Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
                    Exit
                }
                Write-Verbose "* CheckAndInstallPSModulePrereq: The $($ModuleName) PowerShell Module is installed from the PSGallery."
            }
        }
        # Import the Module
        try 
        {
            Import-Module -Name $($ModuleName) -Force
        }
        catch 
        {
            Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
            Exit
        }
        Write-Verbose "* CheckAndInstallPSModulePrereq: The $($ModuleName) PowerShell Module is imported in the current session."
    #endregion Check PS Module status
}

function Invoke-NETFrameworkCheck() {
    <#
    .SYNOPSIS
        Check if the .NET Framework version is 4.7.2 or up.
    .DESCRIPTION
        Check if the .NET Framework version is 4.7.2 or up.
    .EXAMPLE
        Invoke-NETFrameworkCheck
    .CONTEXT
        Windows Virtual Desktops
    .MODIFICATION_HISTORY
        Esther Barthel, MSc - 17/05/20 - Original code
        Esther Barthel, MSc - 17/05/20 - Standardizing script, based on the ControlUp Scripting Standards (version 0.2)
    .COMPONENT
    .NOTES
        Version:        0.1
        Author:         Esther Barthel, MSc
        Creation Date:  2020-05-17
        Updated:        2020-05-17
                        Standardized the function, based on the ControlUp Standards (v0.2)
        Purpose:        Script Action, created for ControlUp WVD Monitoring
        
        Copyright (c) cognition IT. All rights reserved.
    #>
    [CmdletBinding()]
    Param()

    #region Check if the current .NET Framework is 4.7.2 or higher (Release Value = 461808 or higher) prerequisite for the Az PowerShell Module
        If ((Get-ItemProperty 'HKLM:SOFTWAREMicrosoftNET Framework SetupNDPv4Full' -Name Release).Release -ge 461808)
        {
            # Required .NET Framework found
            Write-Verbose ".NET Framework 4.7.2 or up is installed on this machine"
            return $true
        }
        Else
        {
            return $false
        }
    #endregion Check .NET Framework
}

function Get-WVDHostpoolSessionHost () {
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the Subscription ID'
        )]
        [string] $SubscriptionID,
    
        [Parameter(
            Position=1, 
            Mandatory=$false, 
            HelpMessage='Enter the Host Pool name'
        )]
        [string] $HostPoolName,

    [Parameter(
        Position=2, 
        Mandatory=$false, 
        HelpMessage='Enter the Session Host name'
    )]
    [string] $SessionHostName
        )

    #Retrieve the WVD hostPool information for this Subscription
    [array]$psobjectCollection = Get-AzWvdHostPool -SubscriptionId $($azSubscription.Id.ToString()) | 
    ForEach-Object {
        $wvdHostPool = $_
        If ($wvdHostPool.Name -like "$HostPoolName*")
        {
            # Retrieve the SessionHost information for each HostPool
            Get-AzWvdSessionHost -HostPoolName $wvdHostpool.Name -ResourceGroupName $($wvdHostPool.Id.Split("/")[4]) | 
            ForEach-Object {
                $wvdSessionHost = $_
                If ($wvdSessionHost.Name.Split("/")[1] -like "$SessionHostName*")
                {
                    # retrieve both SessionHost and corresponding HostPool information for each SessionHost
                    $wvdSessionHost | Select @{Name='HostPoolName'; Expression={$wvdHostPool.Name}}, 
                        @{Name='SessionHostName'; Expression={$_.Name.Split("/")[1]}}, 
                        AgentVersion, 
                        AllowNewSession, 
                        @{Name='DrainMode'; Expression={if($_.AllowNewSession -eq "True"){return "Off"}else{return "On"}}}, 
                        AsignedUser, 
                        LastHeartBeat,
                        LastUpdateTime,
                        OSVersion,
                        Session, 
                        @{Name='ActiveSessions'; Expression={$_.Session}},  
                        Status,
                        StatusTimestamp,
                        SxSStackVersion, 
                        Type, 
                        UpdateErrorMessage, 
                        UpdateState, 
                        @{Name='HostPoolApplicationGroupReference'; Expression={$wvdHostPool.ApplicationGroupReference}}, 
                        @{Name='HostPoolCustomRdpProperty'; Expression={$wvdHostPool.CustomRdpProperty}}, 
                        @{Name='HostPoolDescription'; Expression={$wvdHostPool.Description}}, 
                        @{Name='HostPoolFriendlyName'; Expression={$wvdHostPool.FriendlyName}}, 
                        @{Name='HostPoolType'; Expression={$wvdHostPool.HostPoolType}}, 
                        @{Name='HostPoolLoadBalancerType'; Expression={$wvdHostPool.LoadBalancerType}}, 
                        @{Name='HostpoolLocation'; Expression={$wvdHostPool.Location}},
                        @{Name='HostpoolMaxSessionLimit'; Expression={$wvdHostPool.MaxSessionLimit}},
                        @{Name='HostpoolResourceGroup'; Expression={$_.Id.Split("/")[4]}}, 
                        @{Name='HostPoolSsoContext'; Expression={$wvdHostPool.SsoContext}}, 
                        @{Name='HostPoolVMTemplate'; Expression={$wvdHostPool.VMTemplate}}, 
                        @{Name='HostPoolValidationEnvironment'; Expression={$wvdHostPool.ValidationEnvironment}}
                } 
            }
        }
    }
    return $psobjectCollection
}

function Set-WVDSessionHostDrainMode () {
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the Session Host Name'
        )]
        [string] $SessionHostName,
    
        [Parameter(
            Position=1, 
            Mandatory=$false, 
            HelpMessage='Enter the Host Pool name'
        )]
        [string] $HostPoolName,

        [Parameter(
            Position=2, 
            Mandatory=$false, 
            HelpMessage='Enter the Resource Group name'
        )]
        [string] $ResourceGroupName,

        [Parameter(
            Position=2, 
            Mandatory=$false, 
            HelpMessage='Enter the Drain Modee'
        )]
        [ValidateSet("ON","OFF")]
        [string] $DrainMode
    )

    # Translate Drain Mode to boolean value
    $boolDrainMode = $false
    If ($DrainMode -eq "OFF")
    {
        $boolDrainMode = $true
    }

    #Update the WVD Session Host Drain Mode (AllowNewSession parameter)
    try
    {
        Update-AzWvdSessionHost -HostPoolName $HostPoolName -ResourceGroupName $ResourceGroupName -Name $SessionHostName -AllowNewSession:$boolDrainMode | Out-Null

    }
    catch
    {
        Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
        Exit
    }
}

function Set-WVDHostpoolMaxSessionLimit () {
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the Hostpool Name'
        )]
        [string] $HostpoolName,
    
        [Parameter(
            Position=1, 
            Mandatory=$true, 
            HelpMessage='Enter the Resource Group name'
        )]
        [string] $ResourceGroupName,

        [Parameter(
            Position=2, 
            Mandatory=$false, 
            HelpMessage='Enter the max session limit'
        )]
        [int] $MaxSessionLimit
    )

    #Update the WVD Hostpool Max Session Limit (AllowNewSession parameter)
    try
    {
        Update-AzWvdHostPool -Name $HostPoolName -ResourceGroupName $ResourceGroupName -MaxSessionLimit $MaxSessionLimit | Out-Null
    }
    catch
    {
        Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
        Exit
    }
}

function Set-WVDHostpoolLoadBalancerType () {
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the Hostpool Name'
        )]
        [string] $HostpoolName,
    
        [Parameter(
            Position=1, 
            Mandatory=$true, 
            HelpMessage='Enter the Resource Group name'
        )]
        [string] $ResourceGroupName,

        [Parameter(
            Position=2, 
            Mandatory=$false, 
            HelpMessage='Enter the Load Balancer Type'
        )]
        [ValidateSet("BreadthFirst","DepthFirst")]
        [string] $LoadBalancerType
    )

    #Update the WVD Hostpool LoadBalancerType
    try
    {
        Update-AzWvdHostPool -Name $HostPoolName -ResourceGroupName $ResourceGroupName -LoadBalancerType $LoadBalancerType | Out-Null
    }
    catch
    {
        Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
        Exit
    }
}

# dot sourcing ControlUp Script Action settings
#region ControlUp Script Standards - version 0.2
    #Requires -Version 5.1

    # Configure a larger output width for the ControlUp PowerShell console
    [int]$outputWidth = 400
    # Altering the size of the PS Buffer
    $PSWindow = (Get-Host).UI.RawUI
    $WideDimensions = $PSWindow.BufferSize
    $WideDimensions.Width = $outputWidth
    $PSWindow.BufferSize = $WideDimensions

    # Ensure Debug information is shown, without the confirmation question after each Write-Debug
    If ($PSBoundParameters['Debug']) {$DebugPreference = "Continue"}
    If ($PSBoundParameters['Verbose']) {$VerbosePreference = "Continue"}
    $ErrorActionPreference = "Stop"

    # ControlUp Monitor
    $rootFolderCUMonitor = "C:Program FilesSmart-XControlUpMonitor"
    $psModuleDLLCUMonitorUser = "ControlUp.PowerShell.User.dll"

    #ControlUp Console
    $rootFolderCUConsole = "WVD-SpringRelease"
#endregion

function Load-CUUserPSModule() {
    [CmdletBinding()]
    Param(
        [Parameter(
            Position=0, 
            Mandatory=$true, 
            HelpMessage='Enter the ControlUp Monitor root folder'
        )]
        [ValidateNotNullOrEmpty()]
        [string] $CUMonitorRootFolder, 

        [Parameter(
            Position=1, 
            Mandatory=$true, 
            HelpMessage='Enter the ControlUp Monitor PowerShell Module DLL to be imported'
        )]
        [ValidateNotNullOrEmpty()]
        [string] $PSModuleDLL
    )
    
    # Load the ControlUp User PowerShell Module
    If (Test-Path $CUMonitorRootFolder)
    {
        # Retrieve the latest version of the CU Monitor
        $cuMonitorPath = (Get-ChildItem -Path $CUMonitorRootFolder -Directory -Depth 1 | Sort Name -Descending)[0].FullName
        try
        {
            # Import PowerShell Module
            Import-Module "$cuMonitorPath$PSModuleDLL" -Force
        }
        catch
        {
            Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
            Exit
        }
    }
    Else
    {
        Write-Error "CU Monitor installation folder ($($CUMonitorRootFolder)) not found"
        Exit
    }
}


#------------------------#
# Script Action Workflow #
#------------------------#
Write-Host ""

#region Retrieve input parameters
#HUser = $args[0]
If ([string]::IsNullOrEmpty($User))
{
    $User = ""
}
#endregion

## Check if the required PowerShell Modules are installed and can be imported
Invoke-CheckInstallAndImportPSModulePrereq -ModuleName "Az.Accounts" #-Verbose
Invoke-CheckInstallAndImportPSModulePrereq -ModuleName "Az.DesktopVirtualization" #-Verbose
# NO need anymore to import the WVD 2019 Fall Release PowerShell Module
# Invoke-CheckInstallAndImportPSModulePrereq -ModuleName "Microsoft.RDInfra.RDPowerShell" -Verbose

## Testing Script output
If ($azSPCredentials = Get-AzSPStoredCredentials)
{
    # Sign in to Azure with a Service Principal with Contributor Role at Subscription level
    try
    {
        $azSPSession = Connect-AzAccount -Credential $azSPCredentials.spCreds -Tenant $($azSPCredentials.tenantID).ToString() -ServicePrincipal -WarningAction SilentlyContinue
    }
    catch
    {
        Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
        Exit
    }

    # Retrieve the Subscription information for the Service Principal (that is logged on)
    $azSubscription = Get-AzSubscription

    try 
    {
        #Retrieve the WVD hostPool information for this Subscription
        [array]$psobjectCollection = Get-AzWvdHostPool -SubscriptionId $($azSubscription.Id.ToString()) | 
        ForEach-Object {
            $wvdHostPool = $_
            If ($wvdHostPool.Name -like "*")
            {
                # Retrieve the User Session information for each HostPool
                Get-AzWvdUserSession -HostPoolName $wvdHostpool.Name -ResourceGroupName $($wvdHostPool.Id.Split("/")[4]) | 
                ForEach-Object {
                    $wvdUserSession = $_
                    If ($wvdUserSession.ActiveDirectoryUserName -like "*$User*")
                    {
                        # retrieve User Sessions per HostPool and SessionHost
                        $wvdUserSession | Select @{Name='HostPoolName'; Expression={$_.Name.Split("/")[0]}}, 
                            @{Name='SessionHostName'; Expression={$_.Name.Split("/")[1]}}, 
                            @{Name='UserSessionID'; Expression={$_.Name.Split("/")[2]}}, 
                            ActiveDirectoryUserName, 
                            ApplicationType,
                            CreateTime,
                            Id,
                            Name,
                            SessionState, 
                            Type,
                            UserPrincipalName, 
                            @{Name='HostpoolResourceGroup'; Expression={$_.Id.Split("/")[4]}},
                            @{Name='Message'; Expression={$Message}} 

                        # Send Message to selected user sessions!
                        #debug: Write-Host "Sending message $Message to user $($wvdUserSession.ActiveDirectoryUserName)" -ForegroundColor Yellow
                        try 
                        {
                            Send-AzWvdUserSessionMessage -HostPoolName $($wvdUserSession.Name.Split("/")[0]) -SessionHostName $($wvdUserSession.Name.Split("/")[1]) -ResourceGroupName $($wvdUserSession.Id.Split("/")[4]) -UserSessionId $($wvdUserSession.Name.Split("/")[2]) -MessageTitle "WVD Admin message" -MessageBody $Message
                        }
                        catch
                        {
                            Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
                            Break
                        }
                    } 
                }
            }
        }
    }
    catch
    {
        Write-Error ("A [" + $_.Exception.GetType().FullName + "] ERROR occurred. " + $_.Exception.Message)
        Exit
    }
    # Return the SessionHost information (limited details with Select)
    Write-Host "WVD 2020 Spring Release User Session Message: " -ForegroundColor Yellow
    if ($psobjectCollection.Count -gt 0)
    {
        $psobjectCollection | Sort-Object HostPoolName, SessionHostName | Select @{Name='HostPool'; Expression={$_.HostPoolName}}, @{Name='SessionHost'; Expression={$_.SessionHostName.Split(".")[0]}}, @{Name='SessionID'; Expression={$_.UserSessionID}}, @{Name='User'; Expression={$_.ActiveDirectoryUserName.Split("")[1]}}, @{Name='State'; Expression={$_.SessionState}}, Message | Format-Table -AutoSize
#        $psobjectCollection | Sort-Object HostPoolName, SessionHostName | Select *
    }
    else 
    {
        Write-Warning "No User Session information could be retrieved"
    }
}
else 
{
    Write-Output ""
    Write-Warning "No Azure Credentials could be retrieved from the stored credentials file for this user."
    Write-Output ""
}

# Disconnect the Azure Session
Disconnect-AzAccount | Out-Null