functions/Invoke-TssRestApi.ps1

function Invoke-TssRestApi {
    <#
    .SYNOPSIS
    Invokes the Secret Server Rest API
 
    .DESCRIPTION
    Invokes the Thycotic Secret Server REST API
 
    .EXAMPLE
    PS C:\> Invoke-TssRestApi -Uri 'https://vault.company.com/api/v1/oauth2/token' -Method POST -Body $body
 
    Performs POST request to the URI specified, returning the output from the endpoint.
    #>

    [Cmdletbinding()]
    param(
        # The REST API Url
        [Parameter(Mandatory,ValueFromPipelineByPropertyName)]
        [Alias('Url')]
        [uri]
        $Uri,

        # A Personal Access Token
        [Parameter(ValueFromPipelineByPropertyName)]
        [Alias('PAT')]
        [string]
        $PersonalAccessToken,

        # Specifies the method used for the web request
        [Parameter(ValueFromPipelineByPropertyName)]
        [ValidateSet('GET','DELETE', 'PATCH', 'POST', 'PUT')]
        [string]
        $Method,

        # Specifies the body of the request.
        # If this value is a string, it will be passed as-is
        # Otherwise, this value will be converted into JSON.
        [Parameter(ValueFromPipelineByPropertyName)]
        [Object]
        $Body,

        # Specifies the content type of the web request.
        # If this parameter is omitted and the request method is POST, Invoke-RestMethod sets the content type to application/x-www-form-urlencoded. Otherwise, the content type is not specified in the call.
        [string]
        $ContentType = 'application/json',

        # Specifies the headers of the web request. Enter a hash table or dictionary.
        [System.Collections.IDictionary]
        [Alias('Header')]
        $Headers,

        # Indicates that the cmdlet uses the credentials of the current user to send the web request (winauth).
        [Alias('UseDefaultCredential')]
        [switch]
        $UseDefaultCredentials,

        # Specifies that the cmdlet uses a proxy server for the request, rather than connecting directly to the Internet resource. Enter the URI of a network proxy server.
        [uri]
        $Proxy,

        # Specifies a user account that has permission to use the proxy server that is specified by the Proxy parameter. The default is the current user.
        # Type a user name, such as "User01" or "Domain01\User01", or enter a PSCredential object, such as one generated by the Get-Credential cmdlet.
        # This parameter is valid only when the Proxy parameter is also used in the command. You cannot use the ProxyCredential and ProxyUseDefaultCredentials parameters in the same command.
        [PSCredential]
        [Management.Automation.CredentialAttribute()]
        $ProxyCredential,

        # Indicates that the cmdlet uses the credentials of the current user to access the proxy server that is specified by the Proxy parameter.
        # This parameter is valid only when the Proxy parameter is also used in the command. You cannot use the ProxyCredential and ProxyUseDefaultCredentials parameters in the same command.
        [switch]
        $ProxyUseDefaultCredentials,

        # The typename of the results.
        [Parameter(ValueFromPipelineByPropertyName)]
        [string[]]
        $PSTypeName,

        # A set of additional properties to add to an object
        [Parameter(ValueFromPipelineByPropertyName)]
        [Collections.IDictionary]
        $Property,

        # A list of property names to remove from an object
        [string[]]
        $RemoveProperty,

        # If provided, will expand a given property returned from the REST api.
        [string]
        $ExpandProperty
    )

    process {
        #region Prepare Parameters
        $irmSplat = @{ } + $PSBoundParameters    # First, copy PSBoundParameters and remove the parameters that aren't Invoke-RestMethod's
        $irmSplat.Remove('PersonalAccessToken') # * -PersonalAccessToken
        $irmSplat.Remove('PSTypeName') # * -PSTypeName
        $irmSplat.Remove('Property') # *-Property
        $irmSplat.Remove('RemoveProperty') # *-RemoveProperty
        $irmSplat.Remove('ExpandProperty') # *-ExpandProperty
        if ($PersonalAccessToken) {
            # If there was a personal access token, set the authorization header
            if ($Headers) {
                # (make sure not to step on other headers).
                $irmSplat.Headers.Authorization = "Bearer $PersonalAccessToken"
            } else {
                $irmSplat.Headers = @{
                    Authorization = "Bearer $PersonalAccessToken"
                }
            }
        } else {
        }
        if ($Body -and $Body -isnot [string]) {
            # If a body was passed, and it wasn't a string
            # $irmSplat.Body = $Body | ConvertTo-Json -Depth 100 # make it JSON.
        }
        if (-not $irmSplat.ContentType) {
            # If no content type was passed
            $irmSplat.ContentType = $ContentType # set it to the default.
        }
        #endregion Prepare Parameters

        #region Call Invoke-RestMethod

        # We call Invoke-RestMethod with the parameters we've passed in.
        # It will take care of converting the results from JSON.
        Invoke-RestMethod @irmSplat |
        & { process {
                # What it will not do is "unroll" them.
                if ($_ -eq 'null') {
                    return
                }
                if ($ExpandProperty) {
                    if ($_.$ExpandProperty) {
                        $_.$ExpandProperty
                    }
                } elseif ($_.Value -and $_.Count) {
                    # If that's what we're dealing with
                    $_.Value # pass value down the pipe.
                } elseif ($_ -notlike '*<html*') {
                    # Otherwise, As long as the value doesn't look like HTML,
                    $_ # pass it down the pipe.
                } else {
                    # If it happened to look like HTML, write an error
                    $PSCmdlet.WriteError(
                        [Management.Automation.ErrorRecord]::new(
                            [Exception]::new("Response was HTML, Request Failed."),
                            "ResultWasHTML", "NotSpecified", $_))
                    $psCmdlet.WriteVerbose("$_") # and write the full content to verbose.
                    return
                }
            } } |
        & { process {
                # One more step of the pipeline will unroll each of the values.
                if ($_ -is [string]) { return $_ }
                if ($null -ne $_.Count -and $_.Count -eq 0) { return }
                if ($PSTypeName -and # If we have a PSTypeName (to apply formatting)
                    $_ -isnot [Management.Automation.ErrorRecord] # and it is not an error (which we do not want to format)
                ) {
                    $_.PSTypeNames.Clear() # then clear the existing typenames and decorate the object.
                    foreach ($t in $PSTypeName) {
                        $_.PSTypeNames.add($T)
                    }
                }

                if ($Property) {
                    foreach ($propKeyValue in $Property.GetEnumerator()) {
                        if ($_.PSObject.Properties[$propKeyValue.Key]) {
                            $_.PSObject.Properties.Remove($propKeyValue.Key)
                        }
                        $_.PSObject.Properties.Add($(
                                if ($propKeyValue.Value -as [ScriptBlock[]]) {
                                    [PSScriptProperty]::new.Invoke(@($propKeyValue.Key) + $propKeyValue.Value)
                                } else {
                                    [PSNoteProperty]::new($propKeyValue.Key, $propKeyValue.Value)
                                }))
                    }
                }
                if ($RemoveProperty) {
                    foreach ($propToRemove in $RemoveProperty) {
                        $_.PSObject.Properties.Remove($propToRemove)
                    }
                }
                return $_ # output the object and we're done.
            } }
        #endregion Call Invoke-RestMethod
    }
}