import { setRoom } from '../base/conference';
import { setLocationURL } from '../base/connection';
import { setConfig } from '../base/config';
import { loadConfig } from '../base/lib-jitsi-meet';

import { APP_WILL_MOUNT, APP_WILL_UNMOUNT } from './actionTypes';
import { _getRouteToRender, _parseURIString } from './functions';

declare var APP: Object;

/**
 * Triggers an in-app navigation to a specific route. Allows navigation to be
 * abstracted between the mobile/React Native and Web/React applications.
 *
 * @param {(string|undefined)} uri - The URI to which to navigate. It may be a
 * full URL with an HTTP(S) scheme, a full or partial URI with the app-specific
 * scheme, or a mere room name.
 * @returns {Function}
 */
export function appNavigate(uri: ?string) {
    return (dispatch: Dispatch<*>, getState: Function) =>
        _appNavigateToOptionalLocation(
            dispatch, getState,
            _parseURIString(uri));
}

/**
 * Triggers an in-app navigation to a specific location URI.
 *
 * @param {Dispatch} dispatch - The redux {@code dispatch} function.
 * @param {Function} getState - The redux function that gets/retrieves the redux
 * state.
 * @param {Object} newLocation - The location URI to navigate to. The value
 * cannot be undefined and is assumed to have all properties such as
 * {@code host} and {@code room} defined values.
 * @private
 * @returns {void}
 */
function _appNavigateToMandatoryLocation(
        dispatch: Dispatch<*>, getState: Function,
        newLocation: Object) {
    // TODO Kostiantyn Tsaregradskyi: We should probably detect if user is
    // currently in a conference and ask her if she wants to close the
    // current conference and start a new one with the new room name or
    // domain.

    const oldLocationURL = getState()['features/base/connection'].locationURL;
    const oldHost = oldLocationURL ? oldLocationURL.host : undefined;
    const newHost = newLocation.host;

    if (oldHost === newHost) {
        dispatchSetLocationURL();
        dispatchSetRoomAndNavigate();
    } else {
        // If the host has changed, we need to load the config of the new host
        // and set it, and only after that we can navigate to a different route.
        _loadConfig(newLocation)
            .then(
                config => configLoaded(/* err */ undefined, config),
                err => configLoaded(err, /* config */ undefined))
            .then(dispatchSetRoomAndNavigate);
    }

    /**
     * Notifies that an attempt to load the config(uration) of domain has
     * completed.
     *
     * @param {string|undefined} err - If the loading has failed, the error
     * detailing the cause of the failure.
     * @param {Object|undefined} config - If the loading has succeeded, the
     * loaded config(uration).
     * @returns {void}
     */
    function configLoaded(err, config) {
        if (err) {
            // XXX The failure could be, for example, because of a
            // certificate-related error. In which case the connection will
            // fail later in Strophe anyway even if we use the default
            // config here.

            // The function loadConfig will log the err.
            return;
        }

        dispatchSetLocationURL();
        dispatch(setConfig(config));
    }

    /**
     * Dispatches {@link setLocationURL} in the redux store.
     *
     * @returns {void}
     */
    function dispatchSetLocationURL() {
        dispatch(
            setLocationURL(
                new URL(
                    (newLocation.protocol || 'https:')

                        // TODO userinfo

                        + newLocation.host
                        + (newLocation.pathname || '/')
                        + newLocation.search
                        + newLocation.hash)));
    }

    /**
     * Dispatches {@link _setRoomAndNavigate} in the redux store.
     *
     * @returns {void}
     */
    function dispatchSetRoomAndNavigate() {
        dispatch(_setRoomAndNavigate(newLocation.room));
    }
}

/**
 * Triggers an in-app navigation to a specific or undefined location (URI).
 *
 * @param {Dispatch} dispatch - The redux {@code dispatch} function.
 * @param {Function} getState - The redux function that gets/retrieves the redux
 * state.
 * @param {Object} location - The location (URI) to navigate to. The value may
 * be undefined.
 * @private
 * @returns {void}
 */
function _appNavigateToOptionalLocation(
        dispatch: Dispatch<*>, getState: Function,
        location: Object) {
    // If the specified location (URI) does not identify a host, use the app's
    // default.
    if (!location || !location.host) {
        const defaultLocation
            = _parseURIString(getState()['features/app'].app._getDefaultURL());

        if (location) {
            location.host = defaultLocation.host;

            // FIXME Turn location's host, hostname, and port properties into
            // setters in order to reduce the risks of inconsistent state.
            location.hostname = defaultLocation.hostname;
            location.port = defaultLocation.port;
            location.protocol = defaultLocation.protocol;
        } else {
            // eslint-disable-next-line no-param-reassign
            location = defaultLocation;
        }
    }

    if (!location.protocol) {
        location.protocol = 'https:';
    }

    _appNavigateToMandatoryLocation(dispatch, getState, location);
}

/**
 * Signals that a specific App will mount (in the terms of React).
 *
 * @param {App} app - The App which will mount.
 * @returns {{
 *     type: APP_WILL_MOUNT,
 *     app: App
 * }}
 */
export function appWillMount(app) {
    return (dispatch: Dispatch<*>) => {
        dispatch({
            type: APP_WILL_MOUNT,
            app
        });

        // TODO There was a redux action creator appInit which I did not like
        // because we already had the redux action creator appWillMount and,
        // respectively, the redux action APP_WILL_MOUNT. So I set out to remove
        // appInit and managed to move everything it was doing but the
        // following. Which is not extremely bad because we haven't moved the
        // API module into its own feature yet so we're bound to work on that in
        // the future.
        typeof APP === 'object' && APP.API.init();
    };
}

/**
 * Signals that a specific App will unmount (in the terms of React).
 *
 * @param {App} app - The App which will unmount.
 * @returns {{
 *     type: APP_WILL_UNMOUNT,
 *     app: App
 * }}
 */
export function appWillUnmount(app) {
    return {
        type: APP_WILL_UNMOUNT,
        app
    };
}

/**
 * Loads config.js from a specific host.
 *
 * @param {Object} location - The location URI which specifies the host to load
 * the config.js from.
 * @returns {Promise<Object>}
 */
function _loadConfig(location: Object) {
    let protocol = location.protocol.toLowerCase();

    // The React Native app supports an app-specific scheme which is sure to not
    // be supported by fetch (or whatever loadConfig utilizes).
    if (protocol !== 'http:' && protocol !== 'https:') {
        protocol = 'https:';
    }

    // TDOO userinfo

    return loadConfig(protocol + location.host + (location.contextRoot || '/'));
}

/**
 * Navigates to a route in accord with a specific redux state.
 *
 * @param {Object} state - The redux state which determines/identifies the route
 * to navigate to.
 * @private
 * @returns {void}
 */
function _navigate(state) {
    const app = state['features/app'].app;
    const routeToRender = _getRouteToRender(state);

    app._navigate(routeToRender);
}

/**
 * Sets room and navigates to new route if needed.
 *
 * @param {string} newRoom - New room name.
 * @private
 * @returns {Function}
 */
function _setRoomAndNavigate(newRoom) {
    return (dispatch, getState) => {
        dispatch(setRoom(newRoom));
        _navigate(getState());
    };
}
