/* eslint-disable require-jsdoc */
/* eslint-disable no-ternary */

class AutosortableCheckboxesComponent {
  constructor(options = {}) {
    this.wrapperField = options.wrapperField;
    this._bindEvent();
    this._order();
    this._normalize();
  }

  // Order by position
  _order() {
    const max = $(this.wrapperField).find(".collection-input").length;
    $(this.wrapperField).find(".collection-input").each((idx, el) => {
      const $positionField = $(el).find("input[name$=\\[position\\]]");
      const position = $positionField.val()
        ? parseInt($positionField.val(), 10)
        : max;

      let $next = $(el).next();
      while ($next.length > 0) {
        const $nextPositionField = $next.find("input[name$=\\[position\\]]");
        const nextPosition = $nextPositionField.val()
          ? parseInt($nextPositionField.val(), 10)
          : max;

        if (position > nextPosition) {
          $next.insertBefore($(el));
        }
        $next = $next.next();
      }
    });
  }

  _findLastPosition() {
    let lastPosition = 0;
    $(this.wrapperField).find(".collection-input").each((idx, el) => {
      const $positionField = $(el).find("input[name$=\\[position\\]]");
      const position = parseInt($positionField.val(), 10);
      if (position > lastPosition) {
        lastPosition = position;
      }
    });
    return lastPosition;
  }

  _normalize() {
    $(this.wrapperField).find(".collection-input .position").each((idx, el) => {
      const $positionField = $(el).parent().find("input[name$=\\[position\\]]");
      if ($positionField.val()) {
        $positionField.val(idx);
        $positionField.prop("disabled", false);
        $(el).html(`${idx + 1}. `);
      }
    });
  }

  _bindEvent() {
    $(this.wrapperField).find("input[type=checkbox]").on("change", (el) => {
      const $parentLabel = $(el.target).parents("label");
      const $positionSelector = $parentLabel.find(".position");
      const $positionField = $parentLabel.find("input[name$=\\[position\\]]");
      const lastPosition = this._findLastPosition();

      if (el.target.checked) {
        $positionField.val(lastPosition + 1);
        $positionField.prop("disabled", false);
        $positionSelector.html(lastPosition + 1);
      } else {
        $positionField.val("");
        $positionField.prop("disabled", true);
        $positionSelector.html("");
      }
      this._order();
      this._normalize();
    });
  }
}

export default function createAutosortableCheckboxes(options) {
  return new AutosortableCheckboxesComponent(options);
}