function Get-Permissions {
    [CmdletBinding()]
    param (
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="ByID")]
        [ValidateScript({ $_ -match "^\d+$" })]
        [ValidateNotNullOrEmpty()]
        [string]
        $Id,
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="ByIP")]
        [parameter(Mandatory=$false,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=1,ParameterSetName="BySubnetId")]
        [ValidateScript({[ipaddress] $_})]
        [ValidateNotNullOrEmpty()]
        [string]
        $IP,
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="ByHostName")]
        [ValidateNotNullOrEmpty()]
        [string]
        $HostName,
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="ByTag")]
        [ValidateScript({ $_ -match "^\d+$" })]
        [ValidateNotNullOrEmpty()]
        [string]
        $TagId,
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="BySubnetId")]
        [ValidateScript({ $_ -match "^\d+$" })]
        [ValidateNotNullOrEmpty()]
        [string]
        $SubnetId,
        [parameter(Mandatory=$true,ValueFromPipeline=$true,ValueFromPipelineByPropertyName=$true,Position=0,ParameterSetName="BySubnetCIDR")]
        [ValidateScript({[ipaddress] $_.Split("/")[0] -and $_.Split("/")[1] -match "\d{1,2}"})]
        [ValidateNotNullOrEmpty()]
        [string]
        $SubnetCIDR
    )
    process {
        [string[]]$visiblePropertiesList = @('Id','Ip','Hostname','Description')
        $visibleProperties = [System.Management.Automation.PSPropertySet]::new('DefaultDisplayPropertySet',$visiblePropertiesList)

        $_params = @{
            Controller = "addresses"
            Method     = "GET"
        }
        switch ($PSCmdlet.ParameterSetName) {
            "ByID"          { $_identifiers = @($id); break }
            "ByIP"          { $_identifiers = ("search",$IP); break }
            "ByHostName"    { $_identifiers = ("search_hostname",$HostName); break }
            "ByTag"         { $_identifiers = ("tags",$TagId,"addresses"); break }
            "BySubnetId"    {
                if ($IP) {
                    $_identifiers = ($IP,$SubnetId)
                } else {
                    $_params.Item("Controller") = "subnets"
                    $_identifiers = ($SubnetId,"addresses")
                }
                break
            }
            "BySubnetCIDR"  {
                $_params.Item("Controller") = "subnets"
                $_subnetId = (Get-Subnet -CIDR $SubnetCIDR).id
                if (!$_subnetId) { throw "Cannot find subnet!" }

                $_identifiers = ($_subnetId,"addresses")
                break
            }
        }
        $_params.Add("Identifiers",$_identifiers)

        Invoke-Request @_params | `
            Add-Member -MemberType MemberSet -Name PSStandardMembers -Value $visibleProperties -PassThru
    }
}
Export-ModuleMember -Function Get-Permissions