/**
 * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
 * SPDX-License-Identifier: GPL-3.0-or-later
 * @author Author: Sascha Nitsch (grumpydeveloper)
 * @internal
 **/

import { RTNode } from './rtnode';
import { RenderTree } from './rendertree';
import Formula from 'fparser';

/**
 * calculate new defintions based on formula
 */
export class RTCalc extends RTNode {
  /** name of the definition */
  private target: string;
  /** expression to calculate */
  private expression: string;

  /**
   * clone function
   * @return a copy of us
   */
  clone(): RTCalc {
    return new RTCalc(this.root, this.target, this.expression);
  }

  /**
   * constructor
   * @param root our parent RenderTree
   * @param target name of the new definition
   * @param expression expression to calculate
   */
  constructor(root: RenderTree, target: string, expression: string) {
    super(root);
    this.target = target;
    this.expression = expression;
  }

  /**
   * create RTCalc from given node into given RenderTree
   * @param root render tree to insert to
   * @param node input node
   * @returns new RTCalc node
   */
  static fromElem(root: RenderTree, node: HTMLElement): RTCalc {
    return new RTCalc(
      root,
      node.getAttribute('name') || '',
      node.innerHTML
    );
  }


  /**
   * render our element into target
   * @param target target to render into
   */
  // eslint-disable-next-line @typescript-eslint/no-unused-vars
  render(target: HTMLElement): void {
    const exp = this.resolveString(this.expression);
    const fObj = new Formula(exp);
    const result = fObj.evaluate({});
    this.root.set(this.target, result.toString());
  }
}