/**

 * Copyright (c) Meta Platforms, Inc. and affiliates.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 *

 * @flow strict-local

 */

import type {LoggerEvent} from 'react-devtools-shared/src/Logger';

import {registerEventLogger} from 'react-devtools-shared/src/Logger';

import {enableLogger} from 'react-devtools-feature-flags';

let currentLoggingIFrame = null;

let currentSessionId = null;

let missedEvents: Array<LoggerEvent> = [];

type LoggerContext = {

  page_url: ?string,

};

export function registerDevToolsEventLogger(

  surface: string,

  fetchAdditionalContext?:

    | (() => LoggerContext)

    | (() => Promise<LoggerContext>),

): void {

  async function logEvent(event: LoggerEvent) {

    if (enableLogger) {

      if (currentLoggingIFrame != null && currentSessionId != null) {

        const {metadata, ...eventWithoutMetadata} = event;

        const additionalContext: LoggerContext | {} =

          fetchAdditionalContext != null ? await fetchAdditionalContext() : {};

        currentLoggingIFrame?.contentWindow?.postMessage(

          {

            source: 'react-devtools-logging',

            event: eventWithoutMetadata,

            context: {

              ...additionalContext,

              metadata: metadata != null ? JSON.stringify(metadata) : '',

              session_id: currentSessionId,

              surface,

              version: process.env.DEVTOOLS_VERSION,

            },

          },

          '*',

        );

      } else {

        missedEvents.push(event);

      }

    }

  }

  function handleLoggingIFrameLoaded(iframe: HTMLIFrameElement) {

    currentLoggingIFrame = iframe;

    if (missedEvents.length > 0) {

      missedEvents.forEach(event => logEvent(event));

      missedEvents = [];

    }

  }

  // If logger is enabled, register a logger that captures logged events

  // and render iframe where the logged events will be reported to

  if (enableLogger) {

    const loggingUrl = process.env.LOGGING_URL;

    const body = document.body;

    if (

      typeof loggingUrl === 'string' &&

      loggingUrl.length > 0 &&

      body != null &&

      currentLoggingIFrame == null

    ) {

      registerEventLogger(logEvent);

      currentSessionId = window.crypto.randomUUID();

      const iframe = document.createElement('iframe');

      iframe.onload = () => handleLoggingIFrameLoaded(iframe);

      iframe.src = loggingUrl;

      body.appendChild(iframe);

    }

  }

}