package com.bee

import org.parboiled.scala._
import java.lang.String
import org.parboiled.errors.{ErrorUtils, ParsingException}

/**
 * Copyright (C) 2013 Orsa Studio
 */
object BeeParser {
  def main(args: Array[String]): Unit = {
    val parser = new BeeParser
    println ( parser.parseBee("one two three four") )
  }
}

class BeeParser extends Parser {
  sealed abstract class AstNode
  case class WordNode(value: String) extends AstNode

  def InputLine = rule { Sentence ~ EOI }

  def Sentence: Rule1[List[WordNode]] = rule { oneOrMore(Word) }
  def Word: Rule1[WordNode] = rule { Word2 ~ WhiteSpace }
  def Word2: Rule1[WordNode] = rule { oneOrMore(Character) ~> WordNode }
  def Character = rule { "a" - "z" | "A" - "Z" }
  def WhiteSpace: Rule0 = rule { zeroOrMore(anyOf(" \n\r\t\f")) }

  // Dont understand this
  override implicit def toRule(string: String) =
    if (string.endsWith(" "))
      str(string.trim) ~ WhiteSpace
    else
      str(string)

  def parseBee(code: String) = {
    val parsingResult = ReportingParseRunner(InputLine).run(code)
    parsingResult.result match {
      case Some(astRoot) => astRoot
      case None => throw new ParsingException("Invalid Bee Language source:\n" +
        ErrorUtils.printParseErrors(parsingResult))
    }
  }

}