ansiToHtml.scala

import scalatags.Text.all._
import collection.mutable
// http://flatuicolors.com/
val red = "#c0392b"
val green = "#27ae60"
val yellow = "#f39c12"
val blue = "#2980b9"
val magenta = "#8e44ad"
val cyan = "#16a085"
val black = "#000"
val white = "#fff"

val foregrounds = Map[fansi.Attr, String](
  fansi.Color.Black -> black,
  fansi.Color.Red -> red,
  fansi.Color.Green-> green,
  fansi.Color.Yellow-> yellow,
  fansi.Color.Blue -> blue,
  fansi.Color.Magenta-> magenta,
  fansi.Color.Cyan -> cyan,
  fansi.Color.White -> white
)
val backgrounds = Map[fansi.Attr, String](
  fansi.Back.Black -> black,
  fansi.Back.Red -> red,
  fansi.Back.Green-> green,
  fansi.Back.Yellow-> yellow,
  fansi.Back.Blue -> blue,
  fansi.Back.Magenta-> magenta,
  fansi.Back.Cyan -> cyan,
  fansi.Back.White -> white
)
def ansiToHtml(ansiInput: String): Frag = {
  val wrapped = mutable.Buffer.empty[scalatags.Text.Frag]
  val parsed = fansi.Str(ansiInput, errorMode = fansi.ErrorMode.Strip)
  val chars = parsed.getChars
  val colors = parsed.getColors

  var i = 0
  var previousColor = 0
  val snippetBuffer = new mutable.StringBuilder()

  def createSnippet() = {
    val foreground = fansi.Color.lookupAttr(previousColor & fansi.Color.mask)
    val background = fansi.Back.lookupAttr(previousColor & fansi.Back.mask)
    val snippet = snippetBuffer.toString
    snippetBuffer.clear()
    wrapped.append(span(
      foregrounds.get(foreground).map(color := _),
      backgrounds.get(background).map(backgroundColor := _),
      snippet
    ))
  }

  while(i < parsed.length){
    if (colors(i) != previousColor && snippetBuffer.nonEmpty) createSnippet()
    previousColor = colors(i)
    snippetBuffer += chars(i)
    i += 1
  }
  createSnippet()
  wrapped.toVector
}

// Example Usage
@ ansiToHtml(Console.RED + "Hello" + Console.RESET + " " + Console.BLUE + "World").render
res6: String = """
<span style="color: #c0392b;">Hello</span><span> </span><span style="color: #2980b9;">World</span>
"""