SONOS volume control

Param(
    [Parameter(Mandatory=$false)]
    [bool]$auto=$false
)

# example file --
# Name,IP,VolumeLimit
# "Sonos1","192.168.0.1",25
# "Sonos2","192.168.0.2",0
$devices = Import-Csv devices.txt

# Port that is used for communication (Default = 1400)
$port = 1400

#Seconds between checks when running on auto mode
$pollRate = 10

#available commands. there are more but these are the only ones I care about
$commands = [ordered]@{
    "1" = "GetVolume"
    "2" = "SetVolume"
    "3" = "Mute"
    "4" = "Unmute"
}

Function Set-Sonos {
    Param(
        [Parameter(Mandatory=$true,Position=0,valueFromPipeline=$true)]
        [string]
        $action,

        [Parameter(Mandatory=$true,Position=1,valueFromPipeline=$true)]
        [string]
        $device,

        [Parameter(Mandatory=$false,Position=2,valueFromPipeline=$true)]
        [int]
        $volume,

        [Parameter(Mandatory=$false,Position=3,valueFromPipeline=$true)]
        [bool]
        $monitor
    )

    $d = $devices[$device-1]

    $deviceName = $d.Name
    $sonosIP = $d.IP
    $limit = $d.VolumeLimit

    Write-Host "Device: $deviceName, IP: $sonosIP, VolumeLimit: $limit"

    $path = "/MediaRenderer/RenderingControl/Control"
    $soapAction = "urn:schemas-upnp-org:service:RenderingControl:1#$action"
    $requiredOptions = @{
                            "SetVolume"= "<DesiredVolume>###DESIRED_VOLUME###</DesiredVolume>";
                            "Mute"="<DesiredMute>1</DesiredMute>";
                            "UnMute"="<DesiredMute>0</DesiredMute>";
                            "GetVolume"="";
                        }

    $options = $requiredOptions[$action]
    $envelope = "<s:Envelope xmlns:s=`"http://schemas.xmlsoap.org/soap/envelope/`" s:encodingStyle=`"http://schemas.xmlsoap.org/soap/encoding/`"><s:Body><u:$action xmlns:u=`"urn:schemas-upnp-org:service:RenderingControl:1`"><InstanceID>0</InstanceID><Channel>Master</Channel>$options</u:$action></s:Body></s:Envelope>"
    $uri = "http://${sonosIP}:$port$path"

    # Section for special Actions
    Switch ($action) {
        'setVolume' {
            if($volume -gt $limit) {
                $volume = $limit
            }
            Write-Host "Set $deviceName Volume $volume"
            $envelope = $envelope.Replace("###DESIRED_VOLUME###", $volume)
        }
    }

    # Create SOAP Request
    $soapRequest = [System.Net.WebRequest]::Create($uri)

    # Set Headers
    $soapRequest.Accept = 'gzip'
    $soapRequest.Method = 'POST'
    $soapRequest.ContentType = 'text/xml; charset="utf-8"'
    $soapRequest.KeepAlive = $false
    $soapRequest.Headers.Add("SOAPACTION", $soapAction)

    # Sending SOAP Request
    $requestStream = $soapRequest.GetRequestStream()
    $envelope = [xml] $envelope
    $envelope.Save($requestStream)
    $requestStream.Close()

    # Sending Complete, Get Response
    $response = $soapRequest.GetResponse()
    $responseStream = $response.GetResponseStream()
    $soapReader = [System.IO.StreamReader]($responseStream)
    $returnXml = [Xml] $soapReader.ReadToEnd()
    $responseStream.Close()
    if($action -eq 'GetVolume') {
        $currentVolume = ($returnXml  | select-xml -xpath "//CurrentVolume").toString()
        Write-Host "Current volume of $deviceName is $currentVolume"
        if($monitor -eq $true -and $currentVolume -gt $limit) {
            Write-Host "This is above the volume limit of $limit"
            Set-Sonos "SetVolume" $device $limit
        }
    }
}


# all this does is continuously poll the devices and sets the volume back to volume limit
# if they go above the limits set above
if($auto) {

   while(1) {
       # keep importing the devices so we can change the limits externally
       $devices = Import-Csv devices.txt
       $i = 1;
      foreach($device in $devices) {
        Set-Sonos "GetVolume" $i -monitor $true
        $i++;
       }
       Start-sleep -seconds $pollRate
   }

} else {


    Write-Host "###############################################################"
    Write-Host "#                                                             #"
    Write-Host "#                   SONOS Volume Controller                   #"
    Write-Host "#                                                             #"
    Write-Host "###############################################################"
    Write-Host ""
    Write-Host "Devices:"
    $i = 1;
    foreach($device in $devices) {
        Write-Host "[$i] $($device.Name)"
        $i++
    }
    Write-Host "----------------"
    Write-Host ""
    Write-Host "Options:"

    foreach($command in $commands.GetEnumerator()) {
        Write-Host "[$($command.key)] $($command.value)"
    }

    Write-Host "----------------"
    Write-Host ""

   $device = Read-Host "Please select a device (by number)"

   $action = Read-Host "Please select an action (by number)"

   $action = $commands["$action"]

   if($action -eq "SetVolume") {
     $volume = Read-Host "Enter Volume (1-50)"
   } else {
     $volume = ""
   }

   Set-Sonos $action $device $volume

}