/**
 *
 * Agora Real Time Engagement
 * Created by Wei Hu in 2021-09.
 * Copyright (c) 2022 Agora IO. All rights reserved.
 *
 */
import * as fs from 'fs';

import * as log from '../common/logger';
import { MetadataInfo } from '../metadata/metadata';
import { RTE } from '../rte/rte';
import rte_addon from '../rte_addon';

type CloseCbType = ((rte: RTE) => void | Promise<void>) | undefined;

export class App {
  constructor(isDefault = false, closeCb: CloseCbType = undefined) {
    rte_addon.rte_nodejs_app_create(this, isDefault);

    this.#closeCb = closeCb;
  }

  private async _onInit(
    rte: RTE,
    manifest: MetadataInfo,
    property: MetadataInfo,
  ): Promise<void> {
    try {
      await this.onInit(rte, manifest, property);
    } catch (e) {
      log.error(`App onInit throws an exception: ${e}`);
    } finally {
      // Notify RTE runtime that app::onInit is completed.
      rte_addon.rte_nodejs_rte_on_init_done(rte, manifest, property);
    }
  }

  async onInit(
    _rte: RTE,
    _manifest: MetadataInfo,
    _property: MetadataInfo,
  ): Promise<void> {
    // Stub for override.
  }

  private async _onClose(rte: RTE): Promise<void> {
    try {
      await this.onClose(rte);
    } catch (e) {
      log.error(`App onClose throws an exception: ${e}`);
    } finally {
      // Notify RTE runtime that app::onClose is completed.
      rte_addon.rte_nodejs_rte_on_deinit_done(rte);

      // JS app prepare to be destroyed.
      rte_addon.rte_nodejs_app_deinit(this);
    }
  }

  async onClose(rte: RTE): Promise<void> {
    if (this.#closeCb) {
      await this.#closeCb(rte);
    }
  }

  run(): void {
    if (rte_addon.rte_nodejs_addon_is_ready()) {
      rte_addon.rte_nodejs_app_run(this);
      return;
    }

    // Postpone the running of the app until all the extensions complete
    // their on_addon_init().
    const intervalId = setInterval(() => {
      if (rte_addon.rte_nodejs_addon_is_ready()) {
        clearInterval(intervalId);
        rte_addon.rte_nodejs_app_run(this);
      }
    }, 20);
  }

  stop(): void {
    rte_addon.rte_nodejs_app_stop(this);
  }

  wait(): void {
    rte_addon.rte_nodejs_app_wait(this);
  }

  #closeCb: CloseCbType;
}

/**
 * This is a convenient function that enables users to setup app property
 * _before_ creating a app instance. That's why this function resides outside
 * the App class.
 */
export function setAppProp(
  appRoot: string,
  property: Record<string, unknown>,
): void {
  const data = fs.readFileSync(`${appRoot}/property.json`, 'utf8');

  let property_json = JSON.parse(data);
  property_json = { ...property_json, ...property };

  fs.writeFileSync(`${appRoot}/property.json`, JSON.stringify(property_json));
}