/**
 * Functions that modify ViewingControls menu.
 *
 * ViewingControls menu is the 3-dot menu that every item in the workbench gets.
 */

import { remove } from "lodash-es";
import { runInAction } from "mobx";
import createGuid from "terriajs-cesium/Source/Core/createGuid";
import { Optional } from "../Core/TypeModifiers";
import CatalogMemberMixin from "../ModelMixins/CatalogMemberMixin";
import { ViewingControl } from "../Models/ViewingControls";
import ViewState from "../ReactViewModels/ViewState";

export type ViewingControlGenerateFunction = (
  item: CatalogMemberMixin.Instance
) => Optional<ViewingControl, "id"> | undefined;

/**
 * Adds a new viewing control menu option.
 *
 * `addMenuItem` adds a `generateViewingControl` function that gets called for each workbench item. This function can at runtime decide if it wants to show an option for the item and return the `ViewingControl` definition or `undefined` if it does not want to show an option.
 *
 * @param viewState - The {@link ViewState} instance.
 * @param generateViewingControl - A function that either generates a {@link ViewingControl} description for the given catalog item or returns `undefined` if no option should be shown
 * @returns A cleanup function that when called will remove the option
 */
export function addMenuItem(
  viewState: ViewState,
  generateViewingControl: ViewingControlGenerateFunction
): () => void {
  runInAction(() => {
    viewState.globalViewingControlOptions.push((item) => {
      const viewingControl = generateViewingControl(item);
      return viewingControl === undefined
        ? undefined
        : {
            // if id is not specified, create one
            id: viewingControl.id ?? createGuid(),
            ...viewingControl
          };
    });
  });
  return () => {
    runInAction(() => {
      remove(
        viewState.globalViewingControlOptions,
        (fn) => fn === generateViewingControl
      );
    });
  };
}