import equal from "fast-deep-equal/es6";
import { isEmpty } from "lodash";
import { debug } from "loglevel";
import type { AdditionalDynamicDataTree } from "./customTreeTypeDefCreator";
import { customTreeTypeDefCreator } from "./customTreeTypeDefCreator";
import CodemirrorTernService from "./CodemirrorTernService";

class CustomDef {
  private static lastCustomDataDef: AdditionalDynamicDataTree | undefined;

  update(customData?: AdditionalDynamicDataTree) {
    if (customData && !isEmpty(customData)) {
      const customDataDef = customTreeTypeDefCreator(customData);
      if (!equal(CustomDef.lastCustomDataDef, customDataDef)) {
        const start = performance.now();

        CodemirrorTernService.updateDef("customDataTree", customDataDef);

        debug(
          "Tern: updateDef for customDataTree took",
          (performance.now() - start).toFixed(),
          "ms",
        );

        CustomDef.lastCustomDataDef = customDataDef;
      }
    } else if (CustomDef.lastCustomDataDef) {
      const start = performance.now();
      CodemirrorTernService.removeDef("customDataTree");
      debug(
        "Tern: removeDef for customDataTree took",
        (performance.now() - start).toFixed(),
        "ms",
      );
      CustomDef.lastCustomDataDef = undefined;
    }
  }
}

/**
 * This method is responsible for both add and remove def in CodemirrorTernService for customDataTree.
 *
 * if customData is not defined then check if lastCustomDataDef was present and remove it.
 *
 * if customData is defined then generate new customDataDef and compare with lastCustomDataDef if different then run updateDef
 * @param customData
 */
const updateCustomDef = new CustomDef().update;

export { updateCustomDef };