/**
 * @license
 * Copyright 2022 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import * as Blockly from 'blockly/core';
import {ProcedureBase, ProcedureBaseJson} from './events_procedure_base';

/** Notifies listeners that a procedure model has been renamed. */
export class ProcedureRename extends ProcedureBase {
  static readonly TYPE = 'procedure_rename';

  /** A string used to check the type of the event. */
  type = ProcedureRename.TYPE;

  private newName: string;

  /**
   * Constructs the procedure rename event.
   *
   * @param workspace The workspace this event is associated with.
   * @param procedure The model this event is associated with.
   * @param oldName The old name of the procedure model.
   * @param newName The (optional) new name of the procedure. If not provided,
   *     the procedure model will be inspected to see what its current
   *     name is.
   */
  constructor(
    workspace: Blockly.Workspace,
    procedure: Blockly.procedures.IProcedureModel,
    readonly oldName: string,
    newName?: string,
  ) {
    super(workspace, procedure);

    this.newName = newName ?? procedure.getName();
  }

  /**
   * Replays the event in the workspace.
   *
   * @param forward if true, play the event forward (redo), otherwise play it
   *     backward (undo).
   */
  run(forward: boolean) {
    const procedureModel = this.getEventWorkspace_()
      .getProcedureMap()
      .get(this.procedure.getId());
    if (!procedureModel) {
      throw new Error(
        'Cannot change the type of a procedure that does not exist ' +
          'in the procedure map',
      );
    }
    if (forward) {
      if (procedureModel.getName() !== this.oldName) return;
      procedureModel.setName(this.newName);
    } else {
      if (procedureModel.getName() !== this.newName) return;
      procedureModel.setName(this.oldName);
    }
  }

  /**
   * Encode the event as JSON.
   *
   * @returns JSON representation.
   */
  toJson(): ProcedureRenameJson {
    const json = super.toJson() as ProcedureRenameJson;
    json['newName'] = this.newName;
    json['oldName'] = this.oldName;
    return json;
  }

  /**
   * Deserializes the JSON event.
   *
   * @param json The JSON representation of a procedure rename event.
   * @param workspace The workspace to deserialize the event into.
   * @returns The new procedure rename event.
   * @internal
   */
  static fromJson(
    json: ProcedureRenameJson,
    workspace: Blockly.Workspace,
  ): ProcedureRename {
    const model = workspace.getProcedureMap().get(json['procedureId']);
    if (!model) {
      throw new Error(
        'Cannot deserialize procedure rename event because the ' +
          'target procedure does not exist',
      );
    }
    return new ProcedureRename(
      workspace,
      model,
      json['oldName'],
      json['newName'],
    );
  }
}

export interface ProcedureRenameJson extends ProcedureBaseJson {
  oldName: string;
  newName: string;
}

Blockly.registry.register(
  Blockly.registry.Type.EVENT,
  ProcedureRename.TYPE,
  ProcedureRename,
);