# encoding: ascii
# api: powershell
# title: Get-Parameter
# description: Get-Parameter is used to obtain all of the parameters for a cmdlet.  It also returns info like aliases and whether a parameter is mandatory.
# version: 0.1
# type: function
# author: halr9000
# license: CC0
# function: Get-Parameter
# x-poshcode-id: 446
# x-derived-from-id: 457
# x-archived: 2008-07-27T03:48:43
#
# Usage:
# @Get-Parameter <Cmdlet Name> 
# Revisions:
# 0.8
# Does not show common params by default, added switch to override
# Added Position property
# 0.81
# Added Type property
# Added WhatIf and Confirm to list of common params
# 0.90
# Added Type (cool!) and two Pipeline properties
# Added Full switch, if enabled you get it all, otherwise…
# Pruned default output so that it fits better into a narrow table.
# Special one time bonus offer: Now includes “gpm” helper function!  This is just a sample scenario which I find useful.
# 0.91 (oisin/x0n)
# Added alias resolving (included nested aliases)
# If command not found, no longer returns a single empty parameter definition
#
function Get-Parameter ( $Cmdlet, [switch]$ShowCommon, [switch]$Full ) {
	
	$command = Get-Command $Cmdlet -ea silentlycontinue	
	
	# resolve aliases (an alias can point to another alias)
	while ($command.CommandType -eq "Alias") {
		$command = Get-Command ($command.definition)
	}
	if (-not $command) { return }
	
	foreach ($paramset in $command.ParameterSets){
		$Output = @()
		foreach ($param in $paramset.Parameters) {
			if ( !$ShowCommon ) {
				if ($param.aliases -match "vb|db|ea|wa|ev|wv|ov|ob|wi|cf") { continue }
			}
			$process = "" | Select-Object Name, Type, ParameterSet, Aliases, Position, IsMandatory,
				Pipeline, PipelineByPropertyName
			$process.Name = $param.Name
			$process.Type = $param.ParameterType.Name 
			if ( $paramset.name -eq "__AllParameterSets" ) { $process.ParameterSet = "Default" }
			else { $process.ParameterSet = $paramset.Name }
			$process.Aliases = $param.aliases
			if ( $param.Position -lt 0 ) { $process.Position = $null }
			else { $process.Position = $param.Position }
			$process.IsMandatory = $param.IsMandatory
			$process.Pipeline =  $param.ValueFromPipeline
			$process.PipelineByPropertyName = $param.ValueFromPipelineByPropertyName
			$output += $process
		}
		if ( !$Full ) { 
			$Output | Select-Object Name, Type, ParameterSet, IsMandatory, Pipeline
		}
		else { Write-Output $Output }
	}
}
