import { Joinpoint, Loop } from "../../Joinpoints.js";
import ClavaJoinPoints from "../ClavaJoinPoints.js";

export default function DoToWhileStmt($doStmt: Loop, labelSuffix: number | string) {
  // do statements have an unconditional first iteration
  const firstIterStmts = $doStmt.scopeNodes.map(($stmt) => $stmt.copy());
  const firstIterScope = ClavaJoinPoints.scope(...firstIterStmts);

  $doStmt.insertBefore(firstIterScope);

  // convert continues in first iteration to jumps to beginning of loop
  const localContinues = [...findLocalContinue(firstIterScope)];
  if (localContinues.length > 0) {
    const $labelDecl = ClavaJoinPoints.labelDecl(
      `__do_loop_head_${labelSuffix}`
    );
    $doStmt.insertBefore(ClavaJoinPoints.labelStmt($labelDecl));

    for (const $continue of localContinues) {
      $continue.replaceWith(ClavaJoinPoints.gotoStmt($labelDecl));
    }
  }

  // convert breaks in first iteration to jumps to after loop
  const localBreaks = [...findLocalBreak(firstIterScope)];
  if (localBreaks.length > 0) {
    const $labelDecl = ClavaJoinPoints.labelDecl(
      `__do_loop_end_${labelSuffix}`
    );
    $doStmt.insertAfter(ClavaJoinPoints.emptyStmt());
    $doStmt.insertAfter(ClavaJoinPoints.labelStmt($labelDecl));

    for (const $break of localBreaks) {
      $break.replaceWith(ClavaJoinPoints.gotoStmt($labelDecl));
    }
  }

  const $while = ClavaJoinPoints.whileStmt($doStmt.cond, $doStmt.body);
  $doStmt.replaceWith($while);
  return $while;
}

function* findLocalBreak($jp: Joinpoint): Generator<Joinpoint> {
  if ($jp.astName === "BreakStmt") {
    yield $jp;
    return;
  }
  if ($jp instanceof Loop) {
    return;
  }
  for (const $child of $jp.children) {
    yield* findLocalBreak($child);
  }
}

function* findLocalContinue($jp: Joinpoint): Generator<Joinpoint> {
  if ($jp.astName === "ContinueStmt") {
    yield $jp;
    return;
  }
  if ($jp instanceof Loop) {
    return;
  }
  for (const $child of $jp.children) {
    yield* findLocalContinue($child);
  }
}