Write-AsciiMotd.ps1

<#
.SYNOPSIS
    Write some awesome ASCII art to the console.	
.DESCRIPTION
	Gets random ASCII art from the asciiart.eu site and prints it out in the console. You can specify the output color using the 'Color' parameter.
.PARAMETER Color
	The color to use to write the ASCII art.
.EXAMPLE
	.\Write-AsciiMotd.ps1 -Color Green
#>

[CmdletBinding()]
param ([System.ConsoleColor]$Color=[System.ConsoleColor]::Cyan, [string]$Category)

$baseUrl = "https://www.asciiart.eu"
$categories = "animals", "art-and-design", "books", "buildings-and-places", "cartoons", "clothing-and-accessories", "comics", "computers", "electronics", "food-and-drinks", "holiday-and-events", "logos", "miscellaneous", "movies", "music", "mythology", "nature", "people", "plants", "religion", "space", "sports-and-outdoors", "television", "toys", "vehicles", "video-games", "weapons"

$progressPreference = 'silentlyContinue'

function Get-AsciiArt ($category) 
{
    $result = $null
    $categories = "/$category"

    do {
        $url = "$baseUrl$categories"
        $r = Invoke-WebRequest $url

        $subcategories = $r.Links | where { $_.Href -like "$categories/*" }

        Write-Verbose "Found $($subcategories.Count) subcategories: $($subcategories.Href)"

        if ($subcategories.Count -eq 0) {
            $preElements = $r.ParsedHtml.getElementsByTagName("PRE") | where { $_.className -notlike "*text-dark*" } 
            Write-Verbose "Found $($preElements.Count) PRE elements."
            $result = $preElements | Get-Random
        } else {
            $categories = $subcategories.Href | Get-Random
            Write-Verbose "Categories set to '$categories'."
        }
    } while (($result -eq $null) -and ($subcategories.Count -gt 0))

    if ($result -ne $null) {
        $art = $result.innerText
    } else {
        $art = ""
    }

    return $art, $url
}

if ($Category -eq "") {
    $Category = $categories | Get-Random
}

$result = Get-AsciiArt $Category

Write-Host "`n$($result[0])" -ForegroundColor $Color
Write-Host "`n  from: $($result[1])" -ForegroundColor DarkGray