/**
 *
 * Agora Real Time Engagement
 * Created by Wei Hu in 2022-04.
 * Copyright (c) 2022 Agora IO. All rights reserved.
 *
 */
import * as log from '../common/logger';
import { Extension } from '../extension/extension';
import { RTE } from '../rte/rte';
import rte_addon from '../rte_addon';

const rtes: Record<string, RTE> = {};

export function ExportRte() {
  return function (
    target: Extension,
    _key: string | symbol,
    descriptor: TypedPropertyDescriptor<
    (rte: RTE, ...args: unknown[]) => Promise<void>
    >,
  ): TypedPropertyDescriptor<(rte: RTE, ...args: unknown[]) => Promise<void>> {
    const originalFunction = descriptor.value;

    if (originalFunction) {
      descriptor.value = function (
        this: Extension,
        rte: RTE,
        ...args: unknown[]
      ): Promise<void> {
        if (!(target instanceof Extension)) {
          throw new Error(
            'ExportRte should apply to a Extension member function.',
          );
        }

        const extension_unique_name_in_graph =
          rte_addon.rte_nodejs_rte_extension_unique_name_in_graph(rte);

        log.info(
          `Register the RTE object of the extension[\
${extension_unique_name_in_graph}].`,
        );

        // Register the RTE object to the global mapping table 'rtes'.
        // CAUTION: The extensions in different extension groups may have the
        // same name, so we cannot directly use the name of the extension as
        // the key.
        rtes[extension_unique_name_in_graph] = rte;

        return originalFunction.apply(this, [ rte, ...args ]);
      };
    }

    return descriptor;
  };
}

export function deleteRte(rte: RTE): boolean {
  const key = (Object.keys(rtes) as Array<string>).find(
    (key) => rtes[key] === rte,
  );
  if (key) {
    return delete rtes[key];
  }
  return false;
}

// Get the exported RTE object.
export async function getExportedRte(
  extension_name: string,
  extension_group_name: string,
  timeout = 10, /* seconds */
): Promise<RTE> {
  const period = 300;
  let waiting = 0;

  const extension_unique_name_in_graph = `${extension_group_name}::\
${extension_name}`;

  return new Promise((resolve, reject) => {
    if (rtes[extension_unique_name_in_graph] !== undefined) {
      resolve(rtes[extension_unique_name_in_graph]);
    } else {
      const timerId = setInterval((): void => {
        if (rtes[extension_unique_name_in_graph] !== undefined) {
          clearInterval(timerId);

          resolve(rtes[extension_unique_name_in_graph]);
        }

        waiting += period;
        if (waiting >= timeout * 1000) {
          clearInterval(timerId);

          log.warn(
            `Failed to get exported rte of extension[\
${extension_unique_name_in_graph}], there are [${Object.keys(
  rtes,
)}] already registered.`,
          );

          reject(
            new Error(
              `The extension[${extension_unique_name_in_graph}] is not ready \
after ${timeout} seconds, or make sure that the extension starts with \
'@ExportRte()'.`,
            ),
          );
        }
      }, period);
    }
  });
}