import {
    createTrackMutedEvent,
    sendAnalytics
} from '../../analytics';
import { JitsiTrackErrors, JitsiTrackEvents } from '../lib-jitsi-meet';
import {
    CAMERA_FACING_MODE,
    MEDIA_TYPE,
    setAudioMuted,
    setVideoMuted,
    VIDEO_MUTISM_AUTHORITY
} from '../media';
import { getLocalParticipant } from '../participants';

import {
    TOGGLE_SCREENSHARING,
    TRACK_ADDED,
    TRACK_CREATE_CANCELED,
    TRACK_CREATE_ERROR,
    TRACK_REMOVED,
    TRACK_UPDATED,
    TRACK_WILL_CREATE
} from './actionTypes';
import { createLocalTracksF, getLocalTrack, getLocalTracks } from './functions';

const logger = require('jitsi-meet-logger').getLogger(__filename);

/**
 * Requests the creating of the desired media type tracks. Desire is expressed
 * by base/media unless the function caller specifies desired media types
 * explicitly and thus override base/media. Dispatches a
 * {@code createLocalTracksA} action for the desired media types for which there
 * are no existing tracks yet.
 *
 * @returns {Function}
 */
export function createDesiredLocalTracks(...desiredTypes) {
    return (dispatch, getState) => {
        const state = getState();

        if (desiredTypes.length === 0) {
            const { audio, video } = state['features/base/media'];

            audio.muted || desiredTypes.push(MEDIA_TYPE.AUDIO);

            // XXX When the app is coming into the foreground from the
            // background in order to handle a URL, it may realize the new
            // background state soon after it has tried to create the local
            // tracks requested by the URL. Ignore
            // VIDEO_MUTISM_AUTHORITY.BACKGROUND and create the local video
            // track if no other VIDEO_MUTISM_AUTHORITY has muted it. The local
            // video track will be muted until the app realizes the new
            // background state.

            // eslint-disable-next-line no-bitwise
            (video.muted & ~VIDEO_MUTISM_AUTHORITY.BACKGROUND)
                || desiredTypes.push(MEDIA_TYPE.VIDEO);
        }

        const availableTypes
            = getLocalTracks(
                    state['features/base/tracks'],
                    /* includePending */ true)
                .map(t => t.mediaType);

        // We need to create the desired tracks which are not already available.
        const createTypes
            = desiredTypes.filter(type => availableTypes.indexOf(type) === -1);

        createTypes.length
            && dispatch(createLocalTracksA({ devices: createTypes }));
    };
}

/**
 * Request to start capturing local audio and/or video. By default, the user
 * facing camera will be selected.
 *
 * @param {Object} [options] - For info @see JitsiMeetJS.createLocalTracks.
 * @returns {Function}
 */
export function createLocalTracksA(options = {}) {
    return (dispatch, getState) => {
        const devices
            = options.devices || [ MEDIA_TYPE.AUDIO, MEDIA_TYPE.VIDEO ];
        const store = {
            dispatch,
            getState
        };

        // The following executes on React Native only at the time of this
        // writing. The effort to port Web's createInitialLocalTracksAndConnect
        // is significant and that's where the function createLocalTracksF got
        // born. I started with the idea a porting so that we could inherit the
        // ability to getUserMedia for audio only or video only if getUserMedia
        // for audio and video fails. Eventually though, I realized that on
        // mobile we do not have combined permission prompts implemented anyway
        // (either because there are no such prompts or it does not make sense
        // to implement them) and the right thing to do is to ask for each
        // device separately.
        for (const device of devices) {
            if (getLocalTrack(
                    getState()['features/base/tracks'],
                    device,
                    /* includePending */ true)) {
                throw new Error(`Local track for ${device} already exists`);
            }

            const gumProcess
                = createLocalTracksF(
                    {
                        cameraDeviceId: options.cameraDeviceId,
                        devices: [ device ],
                        facingMode:
                            options.facingMode || CAMERA_FACING_MODE.USER,
                        micDeviceId: options.micDeviceId
                    },
                    /* firePermissionPromptIsShownEvent */ false,
                    store)
                .then(
                    localTracks => {
                        // Because GUM is called for 1 device (which is actually
                        // a media type 'audio', 'video', 'screen', etc.) we
                        // should not get more than one JitsiTrack.
                        if (localTracks.length !== 1) {
                            throw new Error(
                                `Expected exactly 1 track, but was given ${
                                    localTracks.length} tracks for device: ${
                                    device}.`);
                        }

                        if (gumProcess.canceled) {
                            return _disposeTracks(localTracks)
                                .then(() =>
                                    dispatch(_trackCreateCanceled(device)));
                        }

                        return dispatch(trackAdded(localTracks[0]));
                    },
                    reason =>
                        dispatch(
                            gumProcess.canceled
                                ? _trackCreateCanceled(device)
                                : _onCreateLocalTracksRejected(
                                    reason,
                                    device)));

            /**
             * Cancels the {@code getUserMedia} process represented by this
             * {@code Promise}.
             *
             * @returns {Promise} This {@code Promise} i.e. {@code gumProcess}.
             */
            gumProcess.cancel = () => {
                gumProcess.canceled = true;

                return gumProcess;
            };

            dispatch({
                type: TRACK_WILL_CREATE,
                track: {
                    gumProcess,
                    local: true,
                    mediaType: device
                }
            });
        }
    };
}

/**
 * Calls JitsiLocalTrack#dispose() on all local tracks ignoring errors when
 * track is already disposed. After that signals tracks to be removed.
 *
 * @returns {Function}
 */
export function destroyLocalTracks() {
    return (dispatch, getState) => {
        // First wait until any getUserMedia in progress is settled and then get
        // rid of all local tracks.
        _cancelGUMProcesses(getState)
            .then(() =>
                dispatch(
                    _disposeAndRemoveTracks(
                        getState()['features/base/tracks']
                            .filter(t => t.local)
                            .map(t => t.jitsiTrack))));
    };
}

/**
 * Signals that the local participant is ending screensharing or beginning the
 * screensharing flow.
 *
 * @returns {{
 *     type: TOGGLE_SCREENSHARING,
 * }}
 */
export function toggleScreensharing() {
    return {
        type: TOGGLE_SCREENSHARING
    };
}

/**
 * Replaces one track with another for one renegotiation instead of invoking
 * two renegotiations with a separate removeTrack and addTrack. Disposes the
 * removed track as well.
 *
 * @param {JitsiLocalTrack|null} oldTrack - The track to dispose.
 * @param {JitsiLocalTrack|null} newTrack - The track to use instead.
 * @param {JitsiConference} [conference] - The conference from which to remove
 * and add the tracks. If one is not provided, the conference in the redux store
 * will be used.
 * @returns {Function}
 */
export function replaceLocalTrack(oldTrack, newTrack, conference) {
    return (dispatch, getState) => {
        conference

            // eslint-disable-next-line no-param-reassign
            || (conference = getState()['features/base/conference'].conference);

        return conference.replaceTrack(oldTrack, newTrack)
            .then(() => {
                // We call dispose after doing the replace because dispose will
                // try and do a new o/a after the track removes itself. Doing it
                // after means the JitsiLocalTrack.conference is already
                // cleared, so it won't try and do the o/a.
                const disposePromise
                    = oldTrack
                        ? dispatch(_disposeAndRemoveTracks([ oldTrack ]))
                        : Promise.resolve();

                return disposePromise
                    .then(() => {
                        if (newTrack) {
                            // The mute state of the new track should be
                            // reflected in the app's mute state. For example,
                            // if the app is currently muted and changing to a
                            // new track that is not muted, the app's mute
                            // state should be falsey. As such, emit a mute
                            // event here to set up the app to reflect the
                            // track's mute state. If this is not done, the
                            // current mute state of the app will be reflected
                            // on the track, not vice-versa.
                            const setMuted
                                = newTrack.isVideoTrack()
                                    ? setVideoMuted
                                    : setAudioMuted;
                            const isMuted = newTrack.isMuted();

                            sendAnalytics(createTrackMutedEvent(
                                newTrack.getType(),
                                'track.replaced',
                                isMuted));
                            logger.log(`Replace ${newTrack.getType()} track - ${
                                isMuted ? 'muted' : 'unmuted'}`);

                            return dispatch(setMuted(isMuted));
                        }
                    })
                    .then(() => {
                        if (newTrack) {
                            return dispatch(_addTracks([ newTrack ]));
                        }
                    });
            });
    };
}

/**
 * Create an action for when a new track has been signaled to be added to the
 * conference.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @returns {{ type: TRACK_ADDED, track: Track }}
 */
export function trackAdded(track) {
    return (dispatch, getState) => {
        track.on(
            JitsiTrackEvents.TRACK_MUTE_CHANGED,
            () => dispatch(trackMutedChanged(track)));
        track.on(
            JitsiTrackEvents.TRACK_VIDEOTYPE_CHANGED,
            type => dispatch(trackVideoTypeChanged(track, type)));

        // participantId
        const local = track.isLocal();
        let participantId;

        if (local) {
            const participant = getLocalParticipant(getState);

            if (participant) {
                participantId = participant.id;
            }
        } else {
            participantId = track.getParticipantId();
        }

        return dispatch({
            type: TRACK_ADDED,
            track: {
                jitsiTrack: track,
                local,
                mediaType: track.getType(),
                mirror: _shouldMirror(track),
                muted: track.isMuted(),
                participantId,
                videoStarted: false,
                videoType: track.videoType
            }
        });
    };
}

/**
 * Create an action for when a track's muted state has been signaled to be
 * changed.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @returns {{
 *     type: TRACK_UPDATED,
 *     track: Track
 * }}
 */
export function trackMutedChanged(track) {
    return {
        type: TRACK_UPDATED,
        track: {
            jitsiTrack: track,
            muted: track.isMuted()
        }
    };
}

/**
 * Create an action for when a track has been signaled for removal from the
 * conference.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @returns {{
 *     type: TRACK_REMOVED,
 *     track: Track
 * }}
 */
export function trackRemoved(track) {
    track.removeAllListeners(JitsiTrackEvents.TRACK_MUTE_CHANGED);
    track.removeAllListeners(JitsiTrackEvents.TRACK_VIDEOTYPE_CHANGED);

    return {
        type: TRACK_REMOVED,
        track: {
            jitsiTrack: track
        }
    };
}

/**
 * Signal that track's video started to play.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @returns {{
 *     type: TRACK_UPDATED,
 *     track: Track
 * }}
 */
export function trackVideoStarted(track) {
    return {
        type: TRACK_UPDATED,
        track: {
            jitsiTrack: track,
            videoStarted: true
        }
    };
}

/**
 * Create an action for when participant video type changes.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @param {VIDEO_TYPE|undefined} videoType - Video type.
 * @returns {{
 *     type: TRACK_UPDATED,
 *     track: Track
 * }}
 */
export function trackVideoTypeChanged(track, videoType) {
    return {
        type: TRACK_UPDATED,
        track: {
            jitsiTrack: track,
            videoType
        }
    };
}

/**
 * Signals passed tracks to be added.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)[]} tracks - List of tracks.
 * @private
 * @returns {Function}
 */
function _addTracks(tracks) {
    return dispatch => Promise.all(tracks.map(t => dispatch(trackAdded(t))));
}

/**
 * Cancels and waits for any {@code getUserMedia} process/currently in progress
 * to complete/settle.
 *
 * @param {Function} getState - The redux store {@code getState} function used
 * to obtain the state.
 * @private
 * @returns {Promise} - A {@code Promise} resolved once all
 * {@code gumProcess.cancel()} {@code Promise}s are settled because all we care
 * about here is to be sure that the {@code getUserMedia} callbacks have
 * completed (i.e. returned from the native side).
 */
function _cancelGUMProcesses(getState) {
    const logError
        = error =>
            logger.error('gumProcess.cancel failed', JSON.stringify(error));

    return Promise.all(
        getState()['features/base/tracks']
            .filter(t => t.local)
            .map(({ gumProcess }) =>
                gumProcess && gumProcess.cancel().catch(logError)));
}

/**
 * Disposes passed tracks and signals them to be removed.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)[]} tracks - List of tracks.
 * @protected
 * @returns {Function}
 */
export function _disposeAndRemoveTracks(tracks) {
    return dispatch =>
        _disposeTracks(tracks)
            .then(() =>
                Promise.all(tracks.map(t => dispatch(trackRemoved(t)))));
}

/**
 * Disposes passed tracks.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)[]} tracks - List of tracks.
 * @private
 * @returns {Promise} - A Promise resolved once {@link JitsiTrack.dispose()} is
 * done for every track from the list.
 */
function _disposeTracks(tracks) {
    return Promise.all(
        tracks.map(t =>
            t.dispose()
                .catch(err => {
                    // Track might be already disposed so ignore such an error.
                    // Of course, re-throw any other error(s).
                    if (err.name !== JitsiTrackErrors.TRACK_IS_DISPOSED) {
                        throw err;
                    }
                })));
}

/**
 * Implements the {@code Promise} rejection handler of
 * {@code createLocalTracksA} and {@code createLocalTracksF}.
 *
 * @param {Object} reason - The {@code Promise} rejection reason.
 * @param {string} device - The device/{@code MEDIA_TYPE} associated with the
 * rejection.
 * @private
 * @returns {Function}
 */
function _onCreateLocalTracksRejected({ gum }, device) {
    return dispatch => {
        // If permissions are not allowed, alert the user.
        if (gum) {
            const { error } = gum;

            if (error) {
                // FIXME For whatever reason (which is probably an
                // implementation fault), react-native-webrtc will give the
                // error in one of the following formats depending on whether it
                // is attached to a remote debugger or not. (The remote debugger
                // scenario suggests that react-native-webrtc is at fault
                // because the remote debugger is Google Chrome and then its
                // JavaScript engine will define DOMException. I suspect I wrote
                // react-native-webrtc to return the error in the alternative
                // format if DOMException is not defined.)
                let trackPermissionError;

                switch (error.name) {
                case 'DOMException':
                    trackPermissionError = error.message === 'NotAllowedError';
                    break;

                case 'NotAllowedError':
                    trackPermissionError = error instanceof DOMException;
                    break;
                }

                dispatch({
                    type: TRACK_CREATE_ERROR,
                    permissionDenied: trackPermissionError,
                    trackType: device
                });
            }
        }
    };
}

/**
 * Returns true if the provided {@code JitsiTrack} should be rendered as a
 * mirror.
 *
 * We only want to show a video in mirrored mode when:
 * 1) The video source is local, and not remote.
 * 2) The video source is a camera, not a desktop (capture).
 * 3) The camera is capturing the user, not the environment.
 *
 * TODO Similar functionality is part of lib-jitsi-meet. This function should be
 * removed after https://github.com/jitsi/lib-jitsi-meet/pull/187 is merged.
 *
 * @param {(JitsiLocalTrack|JitsiRemoteTrack)} track - JitsiTrack instance.
 * @private
 * @returns {boolean}
 */
function _shouldMirror(track) {
    return (
        track
            && track.isLocal()
            && track.isVideoTrack()

            // XXX The type of the return value of JitsiLocalTrack's
            // getCameraFacingMode happens to be named CAMERA_FACING_MODE as
            // well, it's defined by lib-jitsi-meet. Note though that the type
            // of the value on the right side of the equality check is defined
            // by jitsi-meet. The type definitions are surely compatible today
            // but that may not be the case tomorrow.
            && track.getCameraFacingMode() === CAMERA_FACING_MODE.USER);
}

/**
 * Signals that track create operation for given media track has been canceled.
 * Will clean up local track stub from the redux state which holds the
 * {@code gumProcess} reference.
 *
 * @param {MEDIA_TYPE} mediaType - The type of the media for which the track was
 * being created.
 * @private
 * @returns {{
 *     type,
 *     trackType: MEDIA_TYPE
 * }}
 */
function _trackCreateCanceled(mediaType) {
    return {
        type: TRACK_CREATE_CANCELED,
        trackType: mediaType
    };
}
