function _translateLegacyConfig()

in react/features/base/config/reducer.js [222:342]
98 lines of code
40 McCabe index (conditional complexity)

function _translateLegacyConfig(oldValue: Object) {
    const newValue = oldValue;

    if (!Array.isArray(oldValue.toolbarButtons)
            && typeof interfaceConfig === 'object' && Array.isArray(interfaceConfig.TOOLBAR_BUTTONS)) {
        newValue.toolbarButtons = interfaceConfig.TOOLBAR_BUTTONS;
    }

    if (!oldValue.toolbarConfig) {
        oldValue.toolbarConfig = {};
    }

    if (typeof oldValue.toolbarConfig.alwaysVisible !== 'boolean'
        && typeof interfaceConfig === 'object'
        && typeof interfaceConfig.TOOLBAR_ALWAYS_VISIBLE === 'boolean') {
        newValue.toolbarConfig.alwaysVisible = interfaceConfig.TOOLBAR_ALWAYS_VISIBLE;
    }

    if (typeof oldValue.toolbarConfig.initialTimeout !== 'number'
        && typeof interfaceConfig === 'object'
        && typeof interfaceConfig.INITIAL_TOOLBAR_TIMEOUT === 'number') {
        newValue.toolbarConfig.initialTimeout = interfaceConfig.INITIAL_TOOLBAR_TIMEOUT;
    }

    if (typeof oldValue.toolbarConfig.timeout !== 'number'
        && typeof interfaceConfig === 'object'
        && typeof interfaceConfig.TOOLBAR_TIMEOUT === 'number') {
        newValue.toolbarConfig.timeout = interfaceConfig.TOOLBAR_TIMEOUT;
    }

    const filteredConferenceInfo = Object.keys(CONFERENCE_HEADER_MAPPING).filter(key => oldValue[key]);

    if (filteredConferenceInfo.length) {
        newValue.conferenceInfo = _getConferenceInfo(oldValue);

        filteredConferenceInfo.forEach(key => {
            // hideRecordingLabel does not mean not render it at all, but autoHide it
            if (key === 'hideRecordingLabel') {
                newValue.conferenceInfo.alwaysVisible
                    = newValue.conferenceInfo.alwaysVisible.filter(c => !CONFERENCE_HEADER_MAPPING[key].includes(c));
                newValue.conferenceInfo.autoHide
                    = _.union(newValue.conferenceInfo.autoHide, CONFERENCE_HEADER_MAPPING[key]);
            } else {
                newValue.conferenceInfo.alwaysVisible
                    = newValue.conferenceInfo.alwaysVisible.filter(c => !CONFERENCE_HEADER_MAPPING[key].includes(c));
                newValue.conferenceInfo.autoHide
                    = newValue.conferenceInfo.autoHide.filter(c => !CONFERENCE_HEADER_MAPPING[key].includes(c));
            }
        });
    }

    if (!oldValue.connectionIndicators
            && typeof interfaceConfig === 'object'
            && (interfaceConfig.hasOwnProperty('CONNECTION_INDICATOR_DISABLED')
                || interfaceConfig.hasOwnProperty('CONNECTION_INDICATOR_AUTO_HIDE_ENABLED')
                || interfaceConfig.hasOwnProperty('CONNECTION_INDICATOR_AUTO_HIDE_TIMEOUT'))) {
        newValue.connectionIndicators = {
            disabled: interfaceConfig.CONNECTION_INDICATOR_DISABLED,
            autoHide: interfaceConfig.CONNECTION_INDICATOR_AUTO_HIDE_ENABLED,
            autoHideTimeout: interfaceConfig.CONNECTION_INDICATOR_AUTO_HIDE_TIMEOUT
        };
    }

    newValue.disabledSounds = newValue.disabledSounds || [];

    if (oldValue.disableJoinLeaveSounds) {
        newValue.disabledSounds.unshift('PARTICIPANT_LEFT_SOUND', 'PARTICIPANT_JOINED_SOUND');
    }

    if (oldValue.disableRecordAudioNotification) {
        newValue.disabledSounds.unshift(
            'RECORDING_ON_SOUND',
            'RECORDING_OFF_SOUND',
            'LIVE_STREAMING_ON_SOUND',
            'LIVE_STREAMING_OFF_SOUND'
        );
    }

    if (oldValue.disableIncomingMessageSound) {
        newValue.disabledSounds.unshift('INCOMING_MSG_SOUND');
    }

    if (oldValue.stereo || oldValue.opusMaxAverageBitrate) {
        newValue.audioQuality = {
            opusMaxAverageBitrate: oldValue.audioQuality?.opusMaxAverageBitrate ?? oldValue.opusMaxAverageBitrate,
            stereo: oldValue.audioQuality?.stereo ?? oldValue.stereo
        };
    }

    if (oldValue.disableModeratorIndicator === undefined
        && typeof interfaceConfig === 'object'
        && interfaceConfig.hasOwnProperty('DISABLE_FOCUS_INDICATOR')) {
        newValue.disableModeratorIndicator = interfaceConfig.DISABLE_FOCUS_INDICATOR;
    }

    newValue.e2ee = newValue.e2ee || {};

    if (oldValue.e2eeLabels) {
        newValue.e2ee.e2eeLabels = oldValue.e2eeLabels;
    }

    if (oldValue.defaultLocalDisplayName === undefined
        && typeof interfaceConfig === 'object'
        && interfaceConfig.hasOwnProperty('DEFAULT_LOCAL_DISPLAY_NAME')) {
        newValue.defaultLocalDisplayName = interfaceConfig.DEFAULT_LOCAL_DISPLAY_NAME;
    }

    newValue.defaultLocalDisplayName
        = newValue.defaultLocalDisplayName || 'me';

    if (oldValue.defaultRemoteDisplayName === undefined
        && typeof interfaceConfig === 'object'
        && interfaceConfig.hasOwnProperty('DEFAULT_REMOTE_DISPLAY_NAME')) {
        newValue.defaultRemoteDisplayName = interfaceConfig.DEFAULT_REMOTE_DISPLAY_NAME;
    }

    newValue.defaultRemoteDisplayName
        = newValue.defaultRemoteDisplayName || 'Fellow Jitster';

    return newValue;
}