LCS Authentication d365fo.tools style

Get-D365LcsApiToken_Invoke-PasswordGrant_Invoke-Authorization.ps1

# For debugging purposes, this script simulates how a call to [Get-D365LcsApiToken](https://github.com/d365collaborative/d365fo.tools/blob/development/d365fo.tools/functions/get-d365lcsapitoken.ps1)
# would execute the Invoke-RestMethod call.
# This script uses code from https://github.com/d365collaborative/PSOAuthHelper by @Splaxi

function Convert-HashToArgStringSwitch {
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSAvoidDefaultValueSwitchParameter", "")]
    [CmdletBinding()]
    [OutputType([System.String])]
    param (
        [HashTable] $InputObject,

        [string] $KeyPrefix = "-",

        [string] $ValuePrefix = ":",

        [switch] $KeepCase = $true
    )

    foreach ($key in $InputObject.Keys) {
        $value = "{0}" -f $InputObject.Item($key).ToString()
        if (-not $KeepCase) { $value = $value.ToLower() }
        "$KeyPrefix$($key)$ValuePrefix$($value)"
    }
}

# TODO Provide your own values for client_id, username and password
# client_secret should not be necessary if the app registration has been configured to allow public client flows
$parms = @{}
$parms.grant_type = "password"
$parms.resource = "https://lcsapi.lcs.dynamics.com"
$parms.client_id = "9b4f4503-b970-4ade-abc6-2c086e4c4929"
# $parms.client_secret = "s3cR3t"
$parms.username = "serviceaccount@domain.com"
$parms.password = "TopSecretPassword"
$parms.scope = "openid"

$body = (Convert-HashToArgStringSwitch -InputObject $parms -KeyPrefix "&" -ValuePrefix "=") -join ""

$body = $body.Substring(1)

$requestParams = @{Method = "Post"; ContentType = "application/x-www-form-urlencoded"; Body = $body}

$AuthProviderUri = "https://login.microsoftonline.com/common/oauth2/token"

try
{
    $Authorization = Invoke-RestMethod $AuthProviderUri @requestParams
    $Authorization
}
catch {
    $PSItem
}