CodeFight - htmlToLuna

htmlToLuna.scala

def htmlToLuna(html: String): String = {
    abstract class HtmlElement{def print(): String}
    
    case class Div(elems: List[HtmlElement]) extends HtmlElement{
        def print() = "DIV(["+ elems.map(_.print).mkString(", ") +"])"
    }

    case class P(elems: List[HtmlElement]) extends HtmlElement{
        def print() = "P([" + elems.map(_.print).mkString(", ") +"])"
    }

    case class B(elems: List[HtmlElement]) extends HtmlElement{
        def print() = "B([" + elems.map(_.print).mkString(", ") +"])"
    }
    
    case class Img() extends HtmlElement{
        def print() = "IMG({})"
    }
    
    val easyToProcessHtml = html.replaceAll("<img />","i").replaceAll("</.{1,3}>","/").replaceAll("<div>","d").replaceAll("<p>","p").replaceAll("<b>","b")

    def getInnerHtml(string: List[Char]) = {
        def _getInnerHtml(str: List[Char], i: Int, retVal: List[Char]) : List[Char]={
            if(i==0) {retVal.reverse}
            else{
                str match {
                    case '/'::tail => _getInnerHtml(tail,i-1,'/'+:retVal)
                    case 'i'::tail => _getInnerHtml(tail,i,'i'+:retVal)
                    case head::tail => _getInnerHtml(tail,i+1,head+:retVal)
                }
            }
        }
        _getInnerHtml(string,1,List())
    }

    def processHtml(str: List[Char], retVal:List[HtmlElement]) : List[HtmlElement] = {
        str match {
            case Nil => 
                retVal.reverse
            case '/'+:tail => 
                processHtml(tail,retVal)
            case 'd'+:tail => 
                val innerHtml = getInnerHtml(tail)
                processHtml(tail.drop(innerHtml.size),Div(processHtml(innerHtml,List()))+:retVal)
            case 'p'+:tail => 
                val innerHtml = getInnerHtml(tail)
                processHtml(tail.drop(innerHtml.size),P(processHtml(innerHtml,List()))+:retVal)
            case 'b'+:tail => 
                val innerHtml = getInnerHtml(tail)
                processHtml(tail.drop(innerHtml.size),B(processHtml(innerHtml,List()))+:retVal)
            case 'i'+:tail => 
                processHtml(tail,Img()+:retVal)
        }
    }
    processHtml(easyToProcessHtml.toList,List()).map(_.print).mkString("")
}