/**

 * 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

 */

import type {PostponedState} from 'react-server/src/ReactFizzServer';

import type {ReactNodeList, ReactFormState} from 'shared/ReactTypes';

import type {BootstrapScriptDescriptor} from 'react-dom-bindings/src/server/ReactFizzConfigDOM';

import type {ImportMap} from '../shared/ReactDOMTypes';

import ReactVersion from 'shared/ReactVersion';

import {

  createRequest,

  resumeRequest,

  startWork,

  startFlowing,

  stopFlowing,

  abort,

} from 'react-server/src/ReactFizzServer';

import {

  createResumableState,

  createRenderState,

  resumeRenderState,

  createRootFormatContext,

} from 'react-dom-bindings/src/server/ReactFizzConfigDOM';

type Options = {

  identifierPrefix?: string,

  namespaceURI?: string,

  nonce?: string,

  bootstrapScriptContent?: string,

  bootstrapScripts?: Array<string | BootstrapScriptDescriptor>,

  bootstrapModules?: Array<string | BootstrapScriptDescriptor>,

  progressiveChunkSize?: number,

  signal?: AbortSignal,

  onError?: (error: mixed) => ?string,

  onPostpone?: (reason: string) => void,

  unstable_externalRuntimeSrc?: string | BootstrapScriptDescriptor,

  importMap?: ImportMap,

  formState?: ReactFormState<any, any> | null,

};

type ResumeOptions = {

  nonce?: string,

  signal?: AbortSignal,

  onError?: (error: mixed) => ?string,

  onPostpone?: (reason: string) => void,

  unstable_externalRuntimeSrc?: string | BootstrapScriptDescriptor,

};

// TODO: Move to sub-classing ReadableStream.

type ReactDOMServerReadableStream = ReadableStream & {

  allReady: Promise<void>,

};

function renderToReadableStream(

  children: ReactNodeList,

  options?: Options,

): Promise<ReactDOMServerReadableStream> {

  return new Promise((resolve, reject) => {

    let onFatalError;

    let onAllReady;

    const allReady = new Promise<void>((res, rej) => {

      onAllReady = res;

      onFatalError = rej;

    });

    function onShellReady() {

      const stream: ReactDOMServerReadableStream = (new ReadableStream(

        {

          type: 'bytes',

          pull: (controller): ?Promise<void> => {

            startFlowing(request, controller);

          },

          cancel: (reason): ?Promise<void> => {

            stopFlowing(request);

            abort(request, reason);

          },

        },

        // $FlowFixMe[prop-missing] size() methods are not allowed on byte streams.

        {highWaterMark: 0},

      ): any);

      // TODO: Move to sub-classing ReadableStream.

      stream.allReady = allReady;

      resolve(stream);

    }

    function onShellError(error: mixed) {

      // If the shell errors the caller of `renderToReadableStream` won't have access to `allReady`.

      // However, `allReady` will be rejected by `onFatalError` as well.

      // So we need to catch the duplicate, uncatchable fatal error in `allReady` to prevent a `UnhandledPromiseRejection`.

      allReady.catch(() => {});

      reject(error);

    }

    const resumableState = createResumableState(

      options ? options.identifierPrefix : undefined,

      options ? options.unstable_externalRuntimeSrc : undefined,

    );

    const request = createRequest(

      children,

      resumableState,

      createRenderState(

        resumableState,

        options ? options.nonce : undefined,

        options ? options.bootstrapScriptContent : undefined,

        options ? options.bootstrapScripts : undefined,

        options ? options.bootstrapModules : undefined,

        options ? options.unstable_externalRuntimeSrc : undefined,

        options ? options.importMap : undefined,

      ),

      createRootFormatContext(options ? options.namespaceURI : undefined),

      options ? options.progressiveChunkSize : undefined,

      options ? options.onError : undefined,

      onAllReady,

      onShellReady,

      onShellError,

      onFatalError,

      options ? options.onPostpone : undefined,

      options ? options.formState : undefined,

    );

    if (options && options.signal) {

      const signal = options.signal;

      if (signal.aborted) {

        abort(request, (signal: any).reason);

      } else {

        const listener = () => {

          abort(request, (signal: any).reason);

          signal.removeEventListener('abort', listener);

        };

        signal.addEventListener('abort', listener);

      }

    }

    startWork(request);

  });

}

function resume(

  children: ReactNodeList,

  postponedState: PostponedState,

  options?: ResumeOptions,

): Promise<ReactDOMServerReadableStream> {

  return new Promise((resolve, reject) => {

    let onFatalError;

    let onAllReady;

    const allReady = new Promise<void>((res, rej) => {

      onAllReady = res;

      onFatalError = rej;

    });

    function onShellReady() {

      const stream: ReactDOMServerReadableStream = (new ReadableStream(

        {

          type: 'bytes',

          pull: (controller): ?Promise<void> => {

            startFlowing(request, controller);

          },

          cancel: (reason): ?Promise<void> => {

            stopFlowing(request);

            abort(request, reason);

          },

        },

        // $FlowFixMe[prop-missing] size() methods are not allowed on byte streams.

        {highWaterMark: 0},

      ): any);

      // TODO: Move to sub-classing ReadableStream.

      stream.allReady = allReady;

      resolve(stream);

    }

    function onShellError(error: mixed) {

      // If the shell errors the caller of `renderToReadableStream` won't have access to `allReady`.

      // However, `allReady` will be rejected by `onFatalError` as well.

      // So we need to catch the duplicate, uncatchable fatal error in `allReady` to prevent a `UnhandledPromiseRejection`.

      allReady.catch(() => {});

      reject(error);

    }

    const request = resumeRequest(

      children,

      postponedState,

      resumeRenderState(

        postponedState.resumableState,

        options ? options.nonce : undefined,

      ),

      options ? options.onError : undefined,

      onAllReady,

      onShellReady,

      onShellError,

      onFatalError,

      options ? options.onPostpone : undefined,

    );

    if (options && options.signal) {

      const signal = options.signal;

      if (signal.aborted) {

        abort(request, (signal: any).reason);

      } else {

        const listener = () => {

          abort(request, (signal: any).reason);

          signal.removeEventListener('abort', listener);

        };

        signal.addEventListener('abort', listener);

      }

    }

    startWork(request);

  });

}

export {renderToReadableStream, resume, ReactVersion as version};