6502-opcodes/firepower-demo/src/main/scala/com/htmlism/firepower/demo/asm/AsmBlock.scala

package com.htmlism.firepower.demo.asm

sealed trait AsmBlock

case class CommentBlock(xs: List[String]) extends AsmBlock

case class NamedCodeBlock(name: String, comment: Option[String], intents: List[AsmBlock.Intent]) extends AsmBlock

case class AnonymousCodeBlock(intents: List[AsmBlock.Intent]) extends AsmBlock

object AsmBlock:
  def interFlatMap[A, B](xs: List[A])(x: List[B], f: A => List[B]): List[B] =
    xs match
      case head :: tail =>
        f(head) ::: tail.flatMap(a => x ::: f(a))

      case Nil =>
        Nil

  def toComment(s: String): String =
    "; " + s

  def withIndent(s: String): String =
    "  " + s

  def toLines(xs: AsmBlock): List[String] =
    xs match
      case CommentBlock(ys) =>
        ys.map(toComment)

      case NamedCodeBlock(label, oComment, intents) =>
        val headerParagraph =
          List(label + ":") ++ oComment.map(toComment).map(withIndent).toList

        val intentParagraphs =
          intents.map(Intent.toLines)

        interFlatMap(headerParagraph :: intentParagraphs)(List(""), identity)

      case AnonymousCodeBlock(intents) =>
        interFlatMap(intents)(List(""), Intent.toLines)

  case class Intent(label: Option[String], instructions: List[Intent.Instruction])

  object Intent:
    case class Instruction(code: String, comment: Option[String])

    def toLines(x: Intent): List[String] =
      x.label.map(toComment).map(withIndent).toList ++ x
        .instructions
        .map(i => i.code + i.comment.map(toComment).map(" " + _).getOrElse(" "))
        .map(withIndent)

object CommentBlock:
  def fromMultiline(s: String): CommentBlock =
    CommentBlock(s.split("\\n").toList)