jitsi_app_c0/react/features/base/devices/reducer.js

import {
    SET_AUDIO_INPUT_DEVICE,
    SET_VIDEO_INPUT_DEVICE,
    UPDATE_DEVICE_LIST
} from './actionTypes';

import { ReducerRegistry } from '../redux';

const DEFAULT_STATE = {
    audioInput: [],
    audioOutput: [],
    videoInput: []
};

/**
 * Listen for actions which changes the state of known and used devices.
 *
 * @param {Object} state - The Redux state of the feature features/base/devices.
 * @param {Object} action - Action object.
 * @param {string} action.type - Type of action.
 * @param {Array<MediaDeviceInfo>} action.devices - All available audio and
 * video devices.
 * @returns {Object}
 */
ReducerRegistry.register(
    'features/base/devices',
    (state = DEFAULT_STATE, action) => {
        switch (action.type) {
        case UPDATE_DEVICE_LIST: {
            const deviceList = _groupDevicesByKind(action.devices);

            return {
                ...deviceList
            };
        }

        // TODO: Changing of current audio and video device id is currently
        // handled outside of react/redux. Fall through to default logic for
        // now.
        case SET_AUDIO_INPUT_DEVICE:
        case SET_VIDEO_INPUT_DEVICE:
        default:
            return state;
        }
    });

/**
 * Converts an array of media devices into an object organized by device kind.
 *
 * @param {Array<MediaDeviceInfo>} devices - Available media devices.
 * @private
 * @returns {Object} An object with the media devices split by type. The keys
 * are device type and the values are arrays with devices matching the device
 * type.
 */
function _groupDevicesByKind(devices) {
    return {
        audioInput: devices.filter(device => device.kind === 'audioinput'),
        audioOutput: devices.filter(device => device.kind === 'audiooutput'),
        videoInput: devices.filter(device => device.kind === 'videoinput')
    };
}