import SimplePass from "@specs-feup/lara/api/lara/pass/SimplePass.js";
import PassResult from "@specs-feup/lara/api/lara/pass/results/PassResult.js";
import { DeclStmt, Joinpoint } from "../../Joinpoints.js";
import ClavaJoinPoints from "../ClavaJoinPoints.js";

/**
 * Decomposes composite declaration statements into separate statements for each variable.
 *
 * This means that a declaration like:
 *
 * ```c
 * int a, b = 10, c;
 * ```
 *
 * Will be decomposed to:
 *
 * ```c
 * int a;
 * int b = 10;
 * int c;
 * ```
 */
export default class DecomposeDeclStmt extends SimplePass {
  protected _name = "DecomposeDeclStmt";

  matchJoinpoint($jp: Joinpoint): boolean {
    if (!($jp instanceof DeclStmt)) {
      return false;
    }
    if ($jp.numChildren <= 1) {
      return false;
    }
    return true;
  }

  transformJoinpoint($jp: DeclStmt): PassResult {
    let $firstDeclStmt: DeclStmt | undefined = undefined;
    for (const $decl of $jp.decls) {
      const $singleDeclStmt = ClavaJoinPoints.declStmt($decl);
      if (!$firstDeclStmt) {
        $firstDeclStmt = $singleDeclStmt;
      }
      $jp.insertBefore($singleDeclStmt);
    }
    $jp.detach();
    return new PassResult(this, $firstDeclStmt!);
  }
}