fx_cast/ext/src/background/receiverSelector/ReceiverSelectorManager.ts

"use strict";

import options from "../../lib/options";
import logger from "../../lib/logger";

import CastManager from "../CastManager";
import receiverDevices from "../receiverDevices";

import { getMediaTypesForPageUrl } from "../../lib/utils";

import {
    ReceiverSelection,
    ReceiverSelectionActionType,
    ReceiverSelectorMediaType
} from "./index";

import ReceiverSelector from "./ReceiverSelector";

async function createSelector() {
    return new ReceiverSelector();
}

let sharedSelector: ReceiverSelector;

async function getSelector() {
    if (!sharedSelector) {
        try {
            sharedSelector = await createSelector();
        } catch (err) {
            throw logger.error("Failed to create receiver selector.");
        }
    }

    return sharedSelector;
}

/**
 * Opens a receiver selector with the specified
 * default/available media types.
 *
 * Returns a promise that:
 *   - Resolves to a ReceiverSelection object if selection is
 *      successful.
 *   - Resolves to null if the selection is cancelled.
 *   - Rejects if the selection fails.
 */
async function getSelection(
    contextTabId: number,
    contextFrameId = 0,
    withMediaSender = false
): Promise<ReceiverSelection | null> {
    return new Promise(async (resolve, reject) => {
        let castInstance = CastManager.getInstance(
            contextTabId,
            contextFrameId
        );

        /**
         * If the current context is running the mirroring app, pretend
         * it doesn't exist because it shouldn't be launched like this.
         */
        if (castInstance?.appId === (await options.get("mirroringAppId"))) {
            castInstance = undefined;
        }

        let defaultMediaType = ReceiverSelectorMediaType.Tab;
        let availableMediaTypes;

        try {
            const { url } = await browser.webNavigation.getFrame({
                tabId: contextTabId,
                frameId: contextFrameId
            });

            availableMediaTypes = getMediaTypesForPageUrl(url);
        } catch {
            logger.error(
                "Failed to locate frame, falling back to default available media types."
            );
            availableMediaTypes = ReceiverSelectorMediaType.File;
        }

        // Enable app media type if initialized sender app is found
        if (castInstance || withMediaSender) {
            defaultMediaType = ReceiverSelectorMediaType.App;
            availableMediaTypes |= ReceiverSelectorMediaType.App;
        }

        const opts = await options.getAll();

        // Remove mirroring media types if mirroring is not enabled
        if (!opts.mirroringEnabled) {
            availableMediaTypes &= ~(
                ReceiverSelectorMediaType.Tab | ReceiverSelectorMediaType.Screen
            );
        }

        // Remove file media type if local media is not enabled
        if (!opts.mediaEnabled || !opts.localMediaEnabled) {
            availableMediaTypes &= ~ReceiverSelectorMediaType.File;
        }

        // Close an existing open selector
        if (sharedSelector && sharedSelector.isOpen) {
            sharedSelector.close();
        }

        // Get a new selector for each selection
        sharedSelector = await createSelector();

        function onReceiverChange() {
            sharedSelector.update(receiverDevices.getDevices());
        }

        receiverDevices.addEventListener("receiverDeviceUp", onReceiverChange);
        receiverDevices.addEventListener(
            "receiverDeviceDown",
            onReceiverChange
        );
        receiverDevices.addEventListener(
            "receiverDeviceUpdated",
            onReceiverChange
        );

        let onSelected: any;
        let onCancelled: any;
        let onError: any;
        let onStop: any;

        type EvParamsType = Parameters<
            typeof sharedSelector.addEventListener
        >[0];

        function storeListener<T>(type: EvParamsType, fn: T) {
            if (type === "selected") {
                onSelected = fn;
            } else if (type === "cancelled") {
                onCancelled = fn;
            } else if (type === "error") {
                onError = fn;
            } else if (type === "stop") {
                onStop = fn;
            }

            return fn;
        }

        function removeListeners() {
            sharedSelector.removeEventListener("selected", onSelected);
            sharedSelector.removeEventListener("cancelled", onCancelled);
            sharedSelector.removeEventListener("error", onError);
            sharedSelector.removeEventListener("stop", onStop);

            receiverDevices.removeEventListener(
                "receiverDeviceUp",
                onReceiverChange
            );
            receiverDevices.removeEventListener(
                "receiverDeviceDown",
                onReceiverChange
            );
            receiverDevices.removeEventListener(
                "receiverDeviceUpdated",
                onReceiverChange
            );
        }

        sharedSelector.addEventListener(
            "selected",
            storeListener("selected", ev => {
                logger.info("Selected receiver", ev.detail);
                resolve({
                    actionType: ReceiverSelectionActionType.Cast,
                    receiver: ev.detail.receiver,
                    mediaType: ev.detail.mediaType,
                    filePath: ev.detail.filePath
                });
                removeListeners();
            })
        );

        sharedSelector.addEventListener(
            "cancelled",
            storeListener("cancelled", () => {
                logger.info("Cancelled receiver selection");
                resolve(null);
                removeListeners();
            })
        );

        sharedSelector.addEventListener(
            "error",
            storeListener("error", () => {
                reject();
                removeListeners();
            })
        );

        sharedSelector.addEventListener(
            "stop",
            storeListener("stop", async ev => {
                logger.info("Stopping receiver app...", ev.detail);

                receiverDevices.stopReceiverApp(ev.detail.receiver.id);

                resolve({
                    actionType: ReceiverSelectionActionType.Stop,
                    receiver: ev.detail.receiver
                });
                removeListeners();
            })
        );

        // Ensure status manager is initialized
        await receiverDevices.init();

        sharedSelector.open(
            receiverDevices.getDevices(),
            defaultMediaType,
            availableMediaTypes,
            castInstance?.appId
        );
    });
}

export default {
    getSelection,
    getSelector
};