Write-ANSI.psm1

# easy reference ANSI sequence. remember to reference as ${ANSI} to avoid colliding
# with surrounding text
$ANSI = "$([char](0x1B))["


function Write-ANSI {
    [CmdletBinding()]
    param(
        [string]$Message
    )

    # extract the numeric portion of each "{:*:}" notated piece
    $ANSICodePieces = ([regex]::Matches($Message, "(?<={:).*?(?=:})")).Value

    # process each piece in turn
    foreach ($acp in $ANSICodePieces) {

        switch ($acp) {
            { $_ -match "" } {
                # reset block, {::}
                $ANSIColorCode = "${ANSI}0m"
            }
            {$_ -match "^,([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])$"} {
                # background color block, {:,#:}
                $ANSIColorCode = "${ANSI}48;5;$($acp -replace ',','')m"
            }
            {$_ -match "^([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5]),([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])$"} {
                # foreground and background color block, {:#,#:}
                $colorCodes = $acp -split ","
                $ANSIColorCode = "${ANSI}38;5;$($colorCodes[0])m${ANSI}48;5;$($colorCodes[1])m"
            }
            {$_ -match "^([01]?[0-9]?[0-9]|2[0-4][0-9]|25[0-5])$"} {
                # foreground color block, {:#:}
                $ANSIColorCode = "${ANSI}38;5;${acp}m"
            }
            default {
                throw "unsupported ANSI color code block"
            }
        }

        # reconstruct the entire notation and replace it with the full ANSI code piece
        $Message = $Message -replace "{:${acp}:}", $ANSIColorCode

    }

    # reset the color at the end of every message regardless, otherwise your
    # prompt or other output could become tainted
    $Message += "${ANSI}0m"

    # actually write the information to screen
    Write-Information -MessageData $Message -InformationAction Continue
}