Returns a list of Parameters, Variables, and Outputs from an Arm template in ~yamlish format. Prepends each line with a prefix for pasting in comments. Prefix is configurable

Get-ArmParamsVarsOutputs.ps1

#Requires -Modules "powershell-yaml"
function Get-ArmParamsVarsOutputs {
    [CmdletBinding()]
    param(
        [string] $ArmTemplatePath,
        [ValidateSet('parameters', 'variables', 'outputs')]
        [string[]] $OutputTypes = @('parameters', 'variables', 'outputs'),
        [string] $Prefix = '//',
        [switch] $NoPrefix
    )
    begin {
        function Get-CleanParameters {
            param(
                [System.Collections.Hashtable]
                $parameters
            )
            if ($parameters.Count -eq 0) {
                Write-Warning "No parameters found in the ARM template"
            }
            $outParams = $parameters.Clone()
            $parameters.Keys.ForEach({
                    Write-Debug "Processing parameter : $_"
                    $keyCount = $outParams[$_].Keys.Count
                    Write-Debug "Key Count : $keyCount"
                    $containsDefault = $outParams[$_].Keys.Contains('defaultValue') -and ![string]::IsNullOrEmpty($outParams[$_].defaultValue)

                    $containsAllowedValues = $outParams[$_].Keys.Contains('allowedValues') -and ![string]::IsNullOrEmpty($outParams[$_].allowedValues)
                    Write-Debug "Contains Default : $containsDefault"
                    Write-Debug "Contains Allowed Values : $containsAllowedValues"
                    if ($keyCount -gt 0 -and $containsDefault -or $containsAllowedValues) {
                        $selectProperties = @()
                        if (![string]::IsNullOrWhiteSpace($outParams[$_].defaultValue)) {
                            $selectProperties += 'defaultValue'
                        }
                        if (![string]::IsNullOrWhiteSpace($outParams[$_].allowedValues)) {
                            $selectProperties += 'allowedValues'
                        }
                        $outParams[$_] = $parameters[$_] | Select-Object -Property $selectProperties

                    } else {
                        $outParams[$_] = ""
                    }
                })
            return $outParams
        }

        # function Get-OutputYaml {
        #     param(
        #         [hashtable] $InputData
        #     )

        #     $InputData | ConvertTo-Yaml -KeepArray | ForEach-Object {
        #         '{0} {1}' -f $Prefix, $_
        #     }

        # }

        function Get-OutputYaml($headingName, $InputData) {
            "$Prefix $HeadingName (from Arm) :`n$Prefix"
            $rawYaml = (ConvertTo-Yaml -Data $InputData).Split("`n")
            Write-Debug "[Get-OutputYaml] Raw Yaml Line Count : $($rawYaml.Count)"
            $rawYaml.ForEach({
                    '{0} {1}' -f $Prefix, $PSItem
                })
        }

        $raw = Get-Content $armTemplatePath -Raw | ConvertFrom-Json -Depth 20 -AsHashtable
        switch ($outputTypes) {
            'parameters' {
                $parameters = Get-CleanParameters -parameters $raw.parameters
            }
            'variables' {
                $variables = $raw.variables
            }
            'outputs' {
                $outputs = $raw.outputs
            }
            default {
                $parameters = $parameters = Get-CleanParameters -parameters $raw.parameters
                $variables = $raw.variables
                $outputs = $raw.outputs
            }
        }
        if ($NoPrefix) {
            $Prefix = ''
        }

    }
    process {
        switch ($outputTypes) {
            'parameters' {
                Get-OutPutYaml -headingName "Parameters" -input $parameters
            }
            'variables' {
                Get-OutPutYaml -headingName "Variables" -input $variables
            }
            'outputs' {
                Get-OutPutYaml -headingName "Outputs" -input $outputs
            }
            default {
                Get-OutPutYaml -headingName "Parameters" -input $parameters

            }
        }

    }
    end {

    }
}