/*
Copyright 2015, 2016 OpenMarket Ltd

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

// TODO: This component is enormous! There's several things which could stand-alone:
//  - Search results component
//  - Drag and drop
//  - File uploading - uploadFile()

var React = require("react");
var ReactDOM = require("react-dom");
var q = require("q");
var classNames = require("classnames");
var Matrix = require("matrix-js-sdk");

var MatrixClientPeg = require("../../MatrixClientPeg");
var ContentMessages = require("../../ContentMessages");
var Modal = require("../../Modal");
var sdk = require('../../index');
var CallHandler = require('../../CallHandler');
var TabComplete = require("../../TabComplete");
var Resend = require("../../Resend");
var dis = require("../../dispatcher");
var Tinter = require("../../Tinter");
var rate_limited_func = require('../../ratelimitedfunc');
var ObjectUtils = require('../../ObjectUtils');
var MatrixTools = require('../../MatrixTools');

import UserProvider from '../../autocomplete/UserProvider';

var DEBUG = false;

if (DEBUG) {
    // using bind means that we get to keep useful line numbers in the console
    var debuglog = console.log.bind(console);
} else {
    var debuglog = function () {};
}

module.exports = React.createClass({
    displayName: 'RoomView',
    propTypes: {
        ConferenceHandler: React.PropTypes.any,

        // Either a room ID or room alias for the room to display.
        // If the room is being displayed as a result of the user clicking
        // on a room alias, the alias should be supplied. Otherwise, a room
        // ID should be supplied.
        roomAddress: React.PropTypes.string.isRequired,

        // If a room alias is passed to roomAddress, a function can be
        // provided here that will be called with the ID of the room
        // once it has been resolved.
        onRoomIdResolved: React.PropTypes.func,

        // An object representing a third party invite to join this room
        // Fields:
        // * inviteSignUrl (string) The URL used to join this room from an email invite
        //                          (given as part of the link in the invite email)
        // * invitedEmail (string) The email address that was invited to this room
        thirdPartyInvite: React.PropTypes.object,

        // Any data about the room that would normally come from the Home Server
        // but has been passed out-of-band, eg. the room name and avatar URL
        // from an email invite (a workaround for the fact that we can't
        // get this information from the HS using an email invite).
        // Fields:
        //  * name (string) The room's name
        //  * avatarUrl (string) The mxc:// avatar URL for the room
        //  * inviterName (string) The display name of the person who
        //  *                      invited us tovthe room
        oobData: React.PropTypes.object,

        // id of an event to jump to. If not given, will go to the end of the
        // live timeline.
        eventId: React.PropTypes.string,

        // where to position the event given by eventId, in pixels from the
        // bottom of the viewport. If not given, will try to put the event
        // 1/3 of the way down the viewport.
        eventPixelOffset: React.PropTypes.number,

        // ID of an event to highlight. If undefined, no event will be highlighted.
        // Typically this will either be the same as 'eventId', or undefined.
        highlightedEventId: React.PropTypes.string,

        // is the RightPanel collapsed?
        rightPanelCollapsed: React.PropTypes.bool,
    },

    getInitialState: function() {
        return {
            room: null,
            roomId: null,
            roomLoading: true,
            editingRoomSettings: false,
            uploadingRoomSettings: false,
            numUnreadMessages: 0,
            draggingFile: false,
            searching: false,
            searchResults: null,
            hasUnsentMessages: false,
            callState: null,
            guestsCanJoin: false,
            canPeek: false,

            // error object, as from the matrix client/server API
            // If we failed to load information about the room,
            // store the error here.
            roomLoadError: null,

            // this is true if we are fully scrolled-down, and are looking at
            // the end of the live timeline. It has the effect of hiding the
            // 'scroll to bottom' knob, among a couple of other things.
            atEndOfLiveTimeline: true,

            showTopUnreadMessagesBar: false,

            auxPanelMaxHeight: undefined,
        }
    },

    componentWillMount: function() {
        this.dispatcherRef = dis.register(this.onAction);
        MatrixClientPeg.get().on("Room", this.onRoom);
        MatrixClientPeg.get().on("Room.timeline", this.onRoomTimeline);
        MatrixClientPeg.get().on("Room.accountData", this.onRoomAccountData);
        MatrixClientPeg.get().on("RoomState.members", this.onRoomStateMember);

        this.tabComplete = new TabComplete({
            allowLooping: false,
            autoEnterTabComplete: true,
            onClickCompletes: true,
            onStateChange: (isCompleting) => {
                this.forceUpdate();
            }
        });

        if (this.props.roomAddress[0] == '#') {
            // we always look up the alias from the directory server:
            // we want the room that the given alias is pointing to
            // right now. We may have joined that alias before but there's
            // no guarantee the alias hasn't subsequently been remapped.
            MatrixClientPeg.get().getRoomIdForAlias(this.props.roomAddress).done((result) => {
                if (this.props.onRoomIdResolved) {
                    this.props.onRoomIdResolved(result.room_id);
                }
                var room = MatrixClientPeg.get().getRoom(result.room_id);
                this.setState({
                    room: room,
                    roomId: result.room_id,
                    roomLoading: !room,
                    hasUnsentMessages: this._hasUnsentMessages(room),
                }, this._onHaveRoom);
            }, (err) => {
                this.setState({
                    roomLoading: false,
                    roomLoadError: err,
                });
            });
        } else {
            var room = MatrixClientPeg.get().getRoom(this.props.roomAddress);
            this.setState({
                roomId: this.props.roomAddress,
                room: room,
                roomLoading: !room,
                hasUnsentMessages: this._hasUnsentMessages(room),
            }, this._onHaveRoom);
        }
    },

    _onHaveRoom: function() {
        // if this is an unknown room then we're in one of three states:
        // - This is a room we can peek into (search engine) (we can /peek)
        // - This is a room we can publicly join or were invited to. (we can /join)
        // - This is a room we cannot join at all. (no action can help us)
        // We can't try to /join because this may implicitly accept invites (!)
        // We can /peek though. If it fails then we present the join UI. If it
        // succeeds then great, show the preview (but we still may be able to /join!).
        // Note that peeking works by room ID and room ID only, as opposed to joining
        // which must be by alias or invite wherever possible (peeking currently does
        // not work over federation).

        // NB. We peek if we are not in the room, although if we try to peek into
        // a room in which we have a member event (ie. we've left) synapse will just
        // send us the same data as we get in the sync (ie. the last events we saw).
        var user_is_in_room = null;
        if (this.state.room) {
            user_is_in_room = this.state.room.hasMembershipState(
                MatrixClientPeg.get().credentials.userId, 'join'
            );

            this._updateAutoComplete();
            this.tabComplete.loadEntries(this.state.room);
        }

        if (!user_is_in_room && this.state.roomId) {
            if (this.props.autoJoin) {
                this.onJoinButtonClicked();
            } else if (this.state.roomId) {
                console.log("Attempting to peek into room %s", this.state.roomId);

                MatrixClientPeg.get().peekInRoom(this.state.roomId).then((room) => {
                    this.setState({
                        room: room,
                        roomLoading: false,
                    });
                    this._onRoomLoaded(room);
                }, (err) => {
                    // This won't necessarily be a MatrixError, but we duck-type
                    // here and say if it's got an 'errcode' key with the right value,
                    // it means we can't peek.
                    if (err.errcode == "M_GUEST_ACCESS_FORBIDDEN") {
                        // This is fine: the room just isn't peekable (we assume).
                        this.setState({
                            roomLoading: false,
                        });
                    } else {
                        throw err;
                    }
                }).done();
            }
        } else if (user_is_in_room) {
            MatrixClientPeg.get().stopPeeking();
            this._onRoomLoaded(this.state.room);
        }
    },

    shouldComponentUpdate: function(nextProps, nextState) {
        return (!ObjectUtils.shallowEqual(this.props, nextProps) ||
                !ObjectUtils.shallowEqual(this.state, nextState));
    },

    componentWillUnmount: function() {
        // set a boolean to say we've been unmounted, which any pending
        // promises can use to throw away their results.
        //
        // (We could use isMounted, but facebook have deprecated that.)
        this.unmounted = true;

        if (this.refs.roomView) {
            // disconnect the D&D event listeners from the room view. This
            // is really just for hygiene - we're going to be
            // deleted anyway, so it doesn't matter if the event listeners
            // don't get cleaned up.
            var roomView = ReactDOM.findDOMNode(this.refs.roomView);
            roomView.removeEventListener('drop', this.onDrop);
            roomView.removeEventListener('dragover', this.onDragOver);
            roomView.removeEventListener('dragleave', this.onDragLeaveOrEnd);
            roomView.removeEventListener('dragend', this.onDragLeaveOrEnd);
        }
        dis.unregister(this.dispatcherRef);
        if (MatrixClientPeg.get()) {
            MatrixClientPeg.get().removeListener("Room", this.onRoom);
            MatrixClientPeg.get().removeListener("Room.timeline", this.onRoomTimeline);
            MatrixClientPeg.get().removeListener("Room.accountData", this.onRoomAccountData);
            MatrixClientPeg.get().removeListener("RoomState.members", this.onRoomStateMember);
        }

        window.removeEventListener('resize', this.onResize);

        // no need to do this as Dir & Settings are now overlays. It just burnt CPU.
        // console.log("Tinter.tint from RoomView.unmount");
        // Tinter.tint(); // reset colourscheme
    },

    onAction: function(payload) {
        switch (payload.action) {
            case 'message_send_failed':
            case 'message_sent':
            case 'message_send_cancelled':
                this.setState({
                    hasUnsentMessages: this._hasUnsentMessages(this.state.room)
                });
                break;
            case 'notifier_enabled':
            case 'upload_failed':
            case 'upload_started':
            case 'upload_finished':
                this.forceUpdate();
                break;
            case 'call_state':
                // don't filter out payloads for room IDs other than props.room because
                // we may be interested in the conf 1:1 room

                if (!payload.room_id) {
                    return;
                }

                var call = this._getCallForRoom();
                var callState;

                if (call) {
                    callState = call.call_state;
                }
                else {
                    callState = "ended";
                }

                // possibly remove the conf call notification if we're now in
                // the conf
                this._updateConfCallNotification();

                this.setState({
                    callState: callState
                });

                break;
        }
    },

    componentWillReceiveProps: function(newProps) {
        if (newProps.roomAddress != this.props.roomAddress) {
            throw new Error("changing room on a RoomView is not supported");
        }

        if (newProps.eventId != this.props.eventId) {
            // when we change focussed event id, hide the search results.
            this.setState({searchResults: null});
        }
    },

    onRoomTimeline: function(ev, room, toStartOfTimeline, removed, data) {
        if (this.unmounted) return;

        // ignore events for other rooms
        if (!this.state.room || room.roomId != this.state.room.roomId) return;

        // ignore anything but real-time updates at the end of the room:
        // updates from pagination will happen when the paginate completes.
        if (toStartOfTimeline || !data || !data.liveEvent) return;

        // no point handling anything while we're waiting for the join to finish:
        // we'll only be showing a spinner.
        if (this.state.joining) return;

        if (ev.getSender() !== MatrixClientPeg.get().credentials.userId) {
            // update unread count when scrolled up
            if (!this.state.searchResults && this.state.atEndOfLiveTimeline) {
                // no change
            }
            else {
                this.setState((state, props) => {
                    return {numUnreadMessages: state.numUnreadMessages + 1};
                });
            }
        }

        // update ther tab complete list as it depends on who most recently spoke,
        // and that has probably just changed
        if (ev.sender) {
            this.tabComplete.onMemberSpoke(ev.sender);
            // nb. we don't need to update the new autocomplete here since
            // its results are currently ordered purely by search score.
        }
    },

    // called when state.room is first initialised (either at initial load,
    // after a successful peek, or after we join the room).
    _onRoomLoaded: function(room) {
        this._calculatePeekRules(room);
    },

    _calculatePeekRules: function(room) {
        var guestAccessEvent = room.currentState.getStateEvents("m.room.guest_access", "");
        if (guestAccessEvent && guestAccessEvent.getContent().guest_access === "can_join") {
            this.setState({
                guestsCanJoin: true
            });
        }

        var historyVisibility = room.currentState.getStateEvents("m.room.history_visibility", "");
        if (historyVisibility && historyVisibility.getContent().history_visibility === "world_readable") {
            this.setState({
                canPeek: true
            });
        }
    },

    onRoom: function(room) {
        // This event is fired when the room is 'stored' by the JS SDK, which
        // means it's now a fully-fledged room object ready to be used, so
        // set it in our state and start using it (ie. init the timeline)
        // This will happen if we start off viewing a room we're not joined,
        // then join it whilst RoomView is looking at that room.
        if (!this.state.room && room.roomId == this._joiningRoomId) {
            this._joiningRoomId = undefined;
            this.setState({
                room: room,
                joining: false,
            });
            this._onRoomLoaded(room);
        }
    },

    updateTint: function() {
        var room = this.state.room;
        if (!room) return;

        var color_scheme_event = room.getAccountData("org.matrix.room.color_scheme");
        var color_scheme = {};
        if (color_scheme_event) {
            color_scheme = color_scheme_event.getContent();
            // XXX: we should validate the event
        }
        console.log("Tinter.tint from updateTint");
        Tinter.tint(color_scheme.primary_color, color_scheme.secondary_color);
    },

    onRoomAccountData: function(room, event) {
        if (room.roomId == this.props.roomId) {
            if (event.getType === "org.matrix.room.color_scheme") {
                var color_scheme = event.getContent();
                // XXX: we should validate the event
                console.log("Tinter.tint from onRoomAccountData");
                Tinter.tint(color_scheme.primary_color, color_scheme.secondary_color);
            }
        }
    },

    onRoomStateMember: function(ev, state, member) {
        // ignore if we don't have a room yet
        if (!this.state.room) {
            return;
        }

        // ignore members in other rooms
        if (member.roomId !== this.state.room.roomId) {
            return;
        }

        // a member state changed in this room, refresh the tab complete list
        this.tabComplete.loadEntries(this.state.room);
        this._updateAutoComplete();

        // if we are now a member of the room, where we were not before, that
        // means we have finished joining a room we were previously peeking
        // into.
        var me = MatrixClientPeg.get().credentials.userId;
        if (this.state.joining && this.state.room.hasMembershipState(me, "join")) {
            this.setState({
                joining: false
            });
        }

        if (this.props.ConferenceHandler &&
            member.userId === this.props.ConferenceHandler.getConferenceUserIdForRoom(member.roomId)) {
            this._updateConfCallNotification();
        }
    },

    _hasUnsentMessages: function(room) {
        return this._getUnsentMessages(room).length > 0;
    },

    _getUnsentMessages: function(room) {
        if (!room) { return []; }
        return room.getPendingEvents().filter(function(ev) {
            return ev.status === Matrix.EventStatus.NOT_SENT;
        });
    },

    _updateConfCallNotification: function() {
        var room = this.state.room;
        if (!room || !this.props.ConferenceHandler) {
            return;
        }
        var confMember = room.getMember(
            this.props.ConferenceHandler.getConferenceUserIdForRoom(room.roomId)
        );

        if (!confMember) {
            return;
        }
        var confCall = this.props.ConferenceHandler.getConferenceCallForRoom(confMember.roomId);

        // A conf call notification should be displayed if there is an ongoing
        // conf call but this cilent isn't a part of it.
        this.setState({
            displayConfCallNotification: (
                (!confCall || confCall.call_state === "ended") &&
                confMember.membership === "join"
            )
        });
    },

    componentDidMount: function() {
        var call = this._getCallForRoom();
        var callState = call ? call.call_state : "ended";
        this.setState({
            callState: callState
        });

        this._updateConfCallNotification();

        window.addEventListener('resize', this.onResize);
        this.onResize();

        // XXX: EVIL HACK to autofocus inviting on empty rooms.
        // We use the setTimeout to avoid racing with focus_composer.
        if (this.state.room &&
            this.state.room.getJoinedMembers().length == 1 &&
            this.state.room.getLiveTimeline() &&
            this.state.room.getLiveTimeline().getEvents() &&
            this.state.room.getLiveTimeline().getEvents().length <= 6)
        {
            var inviteBox = document.getElementById("mx_SearchableEntityList_query");
            setTimeout(function() {
                if (inviteBox) {
                    inviteBox.focus();
                }
            }, 50);
        }
    },

    componentDidUpdate: function() {
        if (this.refs.roomView) {
            var roomView = ReactDOM.findDOMNode(this.refs.roomView);
            if (!roomView.ondrop) {
                roomView.addEventListener('drop', this.onDrop);
                roomView.addEventListener('dragover', this.onDragOver);
                roomView.addEventListener('dragleave', this.onDragLeaveOrEnd);
                roomView.addEventListener('dragend', this.onDragLeaveOrEnd);
            }
        }
    },

    onSearchResultsResize: function() {
        dis.dispatch({ action: 'timeline_resize' }, true);
    },

    onSearchResultsFillRequest: function(backwards) {
        if (!backwards)
            return q(false);

        if (this.state.searchResults.next_batch) {
            debuglog("requesting more search results");
            var searchPromise = MatrixClientPeg.get().backPaginateRoomEventsSearch(
                this.state.searchResults);
            return this._handleSearchResult(searchPromise);
        } else {
            debuglog("no more search results");
            return q(false);
        }
    },

    onResendAllClick: function() {
        var eventsToResend = this._getUnsentMessages(this.state.room);
        eventsToResend.forEach(function(event) {
            Resend.resend(event);
        });
    },

    onCancelAllClick: function() {
        var eventsToResend = this._getUnsentMessages(this.state.room);
        eventsToResend.forEach(function(event) {
            Resend.removeFromQueue(event);
        });
    },

    onJoinButtonClicked: function(ev) {
        var self = this;

        var cli = MatrixClientPeg.get();
        var display_name_promise = q();
        // if this is the first room we're joining, check the user has a display name
        // and if they don't, prompt them to set one.
        // NB. This unfortunately does not re-use the ChangeDisplayName component because
        // it doesn't behave quite as desired here (we want an input field here rather than
        // content-editable, and we want a default).
        if (cli.getRooms().filter((r) => {
            return r.hasMembershipState(cli.credentials.userId, "join");
        })) {
            display_name_promise = cli.getProfileInfo(cli.credentials.userId).then((result) => {
                if (!result.displayname) {
                    var SetDisplayNameDialog = sdk.getComponent('views.dialogs.SetDisplayNameDialog');
                    var dialog_defer = q.defer();
                    var dialog_ref;
                    Modal.createDialog(SetDisplayNameDialog, {
                        currentDisplayName: result.displayname,
                        ref: (r) => {
                            dialog_ref = r;
                        },
                        onFinished: (submitted) => {
                            if (submitted) {
                                cli.setDisplayName(dialog_ref.getValue()).done(() => {
                                    dialog_defer.resolve();
                                });
                            }
                            else {
                                dialog_defer.reject();
                            }
                        }
                    });
                    return dialog_defer.promise;
                }
            });
        }

        display_name_promise.then(() => {
            var sign_url = this.props.thirdPartyInvite ? this.props.thirdPartyInvite.inviteSignUrl : undefined;
            return MatrixClientPeg.get().joinRoom(this.props.roomAddress,
                                                  { inviteSignUrl: sign_url } )
        }).then(function(resp) {
            var roomId = resp.roomId;

            // It is possible that there is no Room yet if state hasn't come down
            // from /sync - joinRoom will resolve when the HTTP request to join succeeds,
            // NOT when it comes down /sync. If there is no room, we'll keep the
            // joining flag set until we see it.

            // We'll need to initialise the timeline when joining, but due to
            // the above, we can't do it here: we do it in onRoom instead,
            // once we have a useable room object.
            var room = MatrixClientPeg.get().getRoom(roomId);
            if (!room) {
                // wait for the room to turn up in onRoom.
                self._joiningRoomId = roomId;
            } else {
                // we've got a valid room, but that might also just mean that
                // it was peekable (so we had one before anyway).  If we are
                // not yet a member of the room, we will need to wait for that
                // to happen, in onRoomStateMember.
                var me = MatrixClientPeg.get().credentials.userId;
                self.setState({
                    joining: !room.hasMembershipState(me, "join"),
                    room: room
                });
            }
        }).catch(function(error) {
            self.setState({
                joining: false,
                joinError: error
            });

            if (!error) return;

            // https://matrix.org/jira/browse/SYN-659
            // Need specific error message if joining a room is refused because the user is a guest and guest access is not allowed
            if (
                error.errcode == 'M_GUEST_ACCESS_FORBIDDEN' ||
                (
                    error.errcode == 'M_FORBIDDEN' &&
                    MatrixClientPeg.get().isGuest()
                )
            ) {
                var NeedToRegisterDialog = sdk.getComponent("dialogs.NeedToRegisterDialog");
                Modal.createDialog(NeedToRegisterDialog, {
                    title: "Failed to join the room",
                    description: "This room is private or inaccessible to guests. You may be able to join if you register."
                });
            } else {
                var msg = error.message ? error.message : JSON.stringify(error);
                var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
                if (msg === "No known servers") {
                    // minging kludge until https://matrix.org/jira/browse/SYN-678 is fixed
                    // 'Error when trying to join an empty room should be more explicit'
                    msg = "It is not currently possible to re-join an empty room.";
                }
                Modal.createDialog(ErrorDialog, {
                    title: "Failed to join room",
                    description: msg
                });
            }
        }).done();

        this.setState({
            joining: true
        });
    },

    onMessageListScroll: function(ev) {
        if (this.refs.messagePanel.isAtEndOfLiveTimeline()) {
            this.setState({
                numUnreadMessages: 0,
                atEndOfLiveTimeline: true,
            });
        }
        else {
            this.setState({
                atEndOfLiveTimeline: false,
            });
        }
        this._updateTopUnreadMessagesBar();
    },

    onDragOver: function(ev) {
        ev.stopPropagation();
        ev.preventDefault();

        ev.dataTransfer.dropEffect = 'none';

        var items = ev.dataTransfer.items;
        if (items.length == 1) {
            if (items[0].kind == 'file') {
                this.setState({ draggingFile : true });
                ev.dataTransfer.dropEffect = 'copy';
            }
        }
    },

    onDrop: function(ev) {
        ev.stopPropagation();
        ev.preventDefault();
        this.setState({ draggingFile : false });
        var files = ev.dataTransfer.files;
        if (files.length == 1) {
            this.uploadFile(files[0]);
        }
    },

    onDragLeaveOrEnd: function(ev) {
        ev.stopPropagation();
        ev.preventDefault();
        this.setState({ draggingFile : false });
    },

    uploadFile: function(file) {
        var self = this;

        if (MatrixClientPeg.get().isGuest()) {
            var NeedToRegisterDialog = sdk.getComponent("dialogs.NeedToRegisterDialog");
            Modal.createDialog(NeedToRegisterDialog, {
                title: "Please Register",
                description: "Guest users can't upload files. Please register to upload."
            });
            return;
        }

        ContentMessages.sendContentToRoom(
            file, this.state.room.roomId, MatrixClientPeg.get()
        ).done(undefined, function(error) {
            var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createDialog(ErrorDialog, {
                title: "Failed to upload file",
                description: error.toString()
            });
        });
    },

    onSearch: function(term, scope) {
        this.setState({
            searchTerm: term,
            searchScope: scope,
            searchResults: {},
            searchHighlights: [],
        });

        // if we already have a search panel, we need to tell it to forget
        // about its scroll state.
        if (this.refs.searchResultsPanel) {
            this.refs.searchResultsPanel.resetScrollState();
        }

        // make sure that we don't end up showing results from
        // an aborted search by keeping a unique id.
        //
        // todo: should cancel any previous search requests.
        this.searchId = new Date().getTime();

        var filter;
        if (scope === "Room") {
            filter = {
                // XXX: it's unintuitive that the filter for searching doesn't have the same shape as the v2 filter API :(
                rooms: [
                    this.state.room.roomId
                ]
            };
        }

        debuglog("sending search request");

        var searchPromise = MatrixClientPeg.get().searchRoomEvents({
            filter: filter,
            term: term,
        });
        this._handleSearchResult(searchPromise).done();
    },

    _handleSearchResult: function(searchPromise) {
        var self = this;

        // keep a record of the current search id, so that if the search terms
        // change before we get a response, we can ignore the results.
        var localSearchId = this.searchId;

        this.setState({
            searchInProgress: true,
        });

        return searchPromise.then(function(results) {
            debuglog("search complete");
            if (self.unmounted || !self.state.searching || self.searchId != localSearchId) {
                console.error("Discarding stale search results");
                return;
            }

            // postgres on synapse returns us precise details of the strings
            // which actually got matched for highlighting.
            //
            // In either case, we want to highlight the literal search term
            // whether it was used by the search engine or not.

            var highlights = results.highlights;
            if (highlights.indexOf(self.state.searchTerm) < 0) {
                highlights = highlights.concat(self.state.searchTerm);
            }

            // For overlapping highlights,
            // favour longer (more specific) terms first
            highlights = highlights.sort(function(a, b) {
                return b.length - a.length });

            self.setState({
                searchHighlights: highlights,
                searchResults: results,
            });
        }, function(error) {
            var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createDialog(ErrorDialog, {
                title: "Search failed",
                description: error.toString()
            });
        }).finally(function() {
            self.setState({
                searchInProgress: false
            });
        });
    },

    getSearchResultTiles: function() {
        var EventTile = sdk.getComponent('rooms.EventTile');
        var SearchResultTile = sdk.getComponent('rooms.SearchResultTile');
        var Spinner = sdk.getComponent("elements.Spinner");

        var cli = MatrixClientPeg.get();

        // XXX: todo: merge overlapping results somehow?
        // XXX: why doesn't searching on name work?

        if (this.state.searchResults.results === undefined) {
            // awaiting results
            return [];
        }

        var ret = [];

        if (this.state.searchInProgress) {
            ret.push(<li key="search-spinner">
                         <Spinner />
                     </li>);
        }

        if (!this.state.searchResults.next_batch) {
            if (this.state.searchResults.results.length == 0) {
                ret.push(<li key="search-top-marker">
                         <h2 className="mx_RoomView_topMarker">No results</h2>
                         </li>
                        );
            } else {
                ret.push(<li key="search-top-marker">
                         <h2 className="mx_RoomView_topMarker">No more results</h2>
                         </li>
                        );
            }
        }

        // once dynamic content in the search results load, make the scrollPanel check
        // the scroll offsets.
        var onWidgetLoad = () => {
            var scrollPanel = this.refs.searchResultsPanel;
            if (scrollPanel) {
                scrollPanel.checkScroll();
            }
        }

        var lastRoomId;

        for (var i = this.state.searchResults.results.length - 1; i >= 0; i--) {
            var result = this.state.searchResults.results[i];

            var mxEv = result.context.getEvent();
            var roomId = mxEv.getRoomId();

            if (!EventTile.haveTileForEvent(mxEv)) {
                // XXX: can this ever happen? It will make the result count
                // not match the displayed count.
                continue;
            }

            if (this.state.searchScope === 'All') {
                if(roomId != lastRoomId) {
                    var room = cli.getRoom(roomId);

                    // XXX: if we've left the room, we might not know about
                    // it. We should tell the js sdk to go and find out about
                    // it. But that's not an issue currently, as synapse only
                    // returns results for rooms we're joined to.
                    var roomName = room ? room.name : "Unknown room "+roomId;

                    ret.push(<li key={mxEv.getId() + "-room"}>
                                 <h1>Room: { roomName }</h1>
                             </li>);
                    lastRoomId = roomId;
                }
            }

            var resultLink = "#/room/"+roomId+"/"+mxEv.getId();

            ret.push(<SearchResultTile key={mxEv.getId()}
                     searchResult={result}
                     searchHighlights={this.state.searchHighlights}
                     resultLink={resultLink}
                     onWidgetLoad={onWidgetLoad}/>);
        }
        return ret;
    },

    onSettingsClick: function() {
        this.showSettings(true);
    },

    onSettingsSaveClick: function() {
        if (!this.refs.room_settings) return;

        this.setState({
            uploadingRoomSettings: true,
        });

        var newName = this.refs.header.getEditedName();
        if (newName !== undefined) {
            this.refs.room_settings.setName(newName);
        }
        var newTopic = this.refs.header.getEditedTopic();
        if (newTopic !== undefined) {
            this.refs.room_settings.setTopic(newTopic);
        }

        this.refs.room_settings.save().then((results) => {
            var fails = results.filter(function(result) { return result.state !== "fulfilled" });
            console.log("Settings saved with %s errors", fails.length);
            if (fails.length) {
                fails.forEach(function(result) {
                    console.error(result.reason);
                });
                var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
                Modal.createDialog(ErrorDialog, {
                    title: "Failed to save settings",
                    description: fails.map(function(result) { return result.reason }).join("\n"),
                });
                // still editing room settings
            }
            else {
                this.setState({
                    editingRoomSettings: false
                });
            }
        }).finally(() => {
            this.setState({
                uploadingRoomSettings: false,
                editingRoomSettings: false
            });
        }).done();
    },

    onCancelClick: function() {
        console.log("updateTint from onCancelClick");
        this.updateTint();
        this.setState({editingRoomSettings: false});
    },

    onLeaveClick: function() {
        dis.dispatch({
            action: 'leave_room',
            room_id: this.state.room.roomId,
        });
    },

    onForgetClick: function() {
        MatrixClientPeg.get().forget(this.state.room.roomId).done(function() {
            dis.dispatch({ action: 'view_next_room' });
        }, function(err) {
            var errCode = err.errcode || "unknown error code";
            var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createDialog(ErrorDialog, {
                title: "Error",
                description: `Failed to forget room (${errCode})`
            });
        });
    },

    onRejectButtonClicked: function(ev) {
        var self = this;
        this.setState({
            rejecting: true
        });
        MatrixClientPeg.get().leave(this.state.roomId).done(function() {
            dis.dispatch({ action: 'view_next_room' });
            self.setState({
                rejecting: false
            });
        }, function(error) {
            console.error("Failed to reject invite: %s", error);

            var msg = error.message ? error.message : JSON.stringify(error);
            var ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
            Modal.createDialog(ErrorDialog, {
                title: "Failed to reject invite",
                description: msg
            });

            self.setState({
                rejecting: false,
                rejectError: error
            });
        });
    },

    onRejectThreepidInviteButtonClicked: function(ev) {
        // We can reject 3pid invites in the same way that we accept them,
        // using /leave rather than /join. In the short term though, we
        // just ignore them.
        // https://github.com/vector-im/vector-web/issues/1134
        dis.dispatch({
            action: 'view_room_directory',
        });
    },

    onSearchClick: function() {
        this.setState({ searching: true });
    },

    onCancelSearchClick: function () {
        this.setState({
            searching: false,
            searchResults: null,
        });
    },

    // jump down to the bottom of this room, where new events are arriving
    jumpToLiveTimeline: function() {
        this.refs.messagePanel.jumpToLiveTimeline();
    },

    // jump up to wherever our read marker is
    jumpToReadMarker: function() {
        this.refs.messagePanel.jumpToReadMarker();
    },

    // update the read marker to match the read-receipt
    forgetReadMarker: function(ev) {
        ev.stopPropagation();
        this.refs.messagePanel.forgetReadMarker();
    },

    // decide whether or not the top 'unread messages' bar should be shown
    _updateTopUnreadMessagesBar: function() {
        if (!this.refs.messagePanel)
            return;

        var pos = this.refs.messagePanel.getReadMarkerPosition();

        // we want to show the bar if the read-marker is off the top of the
        // screen.
        var showBar = (pos < 0);

        if (this.state.showTopUnreadMessagesBar != showBar) {
            this.setState({showTopUnreadMessagesBar: showBar},
                          this.onChildResize);
        }
    },

    // get the current scroll position of the room, so that it can be
    // restored when we switch back to it.
    //
    // If there is no special scroll state (ie, we are following the live
    // timeline), returns null. Otherwise, returns an object with the following
    // properties:
    //
    //    focussedEvent: the ID of the 'focussed' event. Typically this is the
    //        last event fully visible in the viewport, though if we have done
    //        an explicit scroll to an explicit event, it will be that event.
    //
    //    pixelOffset: the number of pixels the window is scrolled down from
    //        the focussedEvent.
    //
    //
    getScrollState: function() {
        var messagePanel = this.refs.messagePanel;
        if (!messagePanel) return null;

        // if we're following the live timeline, we want to return null; that
        // means that, if we switch back, we will jump to the read-up-to mark.
        //
        // That should be more intuitive than slavishly preserving the current
        // scroll state, in the case where the room advances in the meantime
        // (particularly in the case that the user reads some stuff on another
        // device).
        //
        if (this.state.atEndOfLiveTimeline) {
            return null;
        }

        var scrollState = messagePanel.getScrollState();

        if (scrollState.stuckAtBottom) {
            // we don't really expect to be in this state, but it will
            // occasionally happen when no scroll state has been set on the
            // messagePanel (ie, we didn't have an initial event (so it's
            // probably a new room), there has been no user-initiated scroll, and
            // no read-receipts have arrived to update the scroll position).
            //
            // Return null, which will cause us to scroll to last unread on
            // reload.
            return null;
        }

        return {
            focussedEvent: scrollState.trackedScrollToken,
            pixelOffset: scrollState.pixelOffset,
        };
    },

    onResize: function(e) {
        // It seems flexbox doesn't give us a way to constrain the auxPanel height to have
        // a minimum of the height of the video element, whilst also capping it from pushing out the page
        // so we have to do it via JS instead.  In this implementation we cap the height by putting
        // a maxHeight on the underlying remote video tag.

        // header + footer + status + give us at least 120px of scrollback at all times.
        var auxPanelMaxHeight = window.innerHeight -
                (83 + // height of RoomHeader
                 36 + // height of the status area
                 72 + // minimum height of the message compmoser
                 (this.state.editingRoomSettings ? (window.innerHeight * 0.3) : 120)); // amount of desired scrollback

        // XXX: this is a bit of a hack and might possibly cause the video to push out the page anyway
        // but it's better than the video going missing entirely
        if (auxPanelMaxHeight < 50) auxPanelMaxHeight = 50;

        this.setState({auxPanelMaxHeight: auxPanelMaxHeight});

        // changing the maxHeight on the auxpanel will trigger a callback go
        // onChildResize, so no need to worry about that here.
    },

    onFullscreenClick: function() {
        dis.dispatch({
            action: 'video_fullscreen',
            fullscreen: true
        }, true);
    },

    onMuteAudioClick: function() {
        var call = this._getCallForRoom();
        if (!call) {
            return;
        }
        var newState = !call.isMicrophoneMuted();
        call.setMicrophoneMuted(newState);
        this.setState({
            audioMuted: newState
        });
    },

    onMuteVideoClick: function() {
        var call = this._getCallForRoom();
        if (!call) {
            return;
        }
        var newState = !call.isLocalVideoMuted();
        call.setLocalVideoMuted(newState);
        this.setState({
            videoMuted: newState
        });
    },

    onChildResize: function() {
        // no longer anything to do here
    },

    showSettings: function(show) {
        // XXX: this is a bit naughty; we should be doing this via props
        if (show) {
            this.setState({editingRoomSettings: true});
        }
    },

    /**
     * called by the parent component when PageUp/Down/etc is pressed.
     *
     * We pass it down to the scroll panel.
     */
    handleScrollKey: function(ev) {
        var panel;
        if(this.refs.searchResultsPanel) {
            panel = this.refs.searchResultsPanel;
        } else if(this.refs.messagePanel) {
            panel = this.refs.messagePanel;
        }

        if(panel) {
            panel.handleScrollKey(ev);
        }
    },

    /**
     * Get the ID of the displayed room
     *
     * Returns null if the RoomView was instantiated on a room alias and
     * we haven't yet joined the room.
     */
    getRoomId: function() {
        if (!this.state.room) {
            return null;
        }
        return this.state.room.roomId;
    },

    /**
     * get any current call for this room
     */
    _getCallForRoom: function() {
        if (!this.state.room) {
            return null;
        }
        return CallHandler.getCallForRoom(this.state.room.roomId);
    },

    // this has to be a proper method rather than an unnamed function,
    // otherwise react calls it with null on each update.
    _gatherTimelinePanelRef: function(r) {
        this.refs.messagePanel = r;
        if(r) {
            console.log("updateTint from RoomView._gatherTimelinePanelRef");
            this.updateTint();
        }
    },

    _updateAutoComplete: function() {
        const myUserId = MatrixClientPeg.get().credentials.userId;
        const members = this.state.room.getJoinedMembers().filter(function(member) {
            if (member.userId !== myUserId) return true;
        });
        UserProvider.getInstance().setUserList(members);
    },

    render: function() {
        var RoomHeader = sdk.getComponent('rooms.RoomHeader');
        var MessageComposer = sdk.getComponent('rooms.MessageComposer');
        var RoomSettings = sdk.getComponent("rooms.RoomSettings");
        var AuxPanel = sdk.getComponent("rooms.AuxPanel");
        var SearchBar = sdk.getComponent("rooms.SearchBar");
        var ScrollPanel = sdk.getComponent("structures.ScrollPanel");
        var TintableSvg = sdk.getComponent("elements.TintableSvg");
        var RoomPreviewBar = sdk.getComponent("rooms.RoomPreviewBar");
        var Loader = sdk.getComponent("elements.Spinner");
        var TimelinePanel = sdk.getComponent("structures.TimelinePanel");

        if (!this.state.room) {
                if (this.state.roomLoading) {
                    return (
                        <div className="mx_RoomView">
                            <Loader />
                        </div>
                    );
                }
                else {
                    var inviterName = undefined;
                    if (this.props.oobData) {
                        inviterName = this.props.oobData.inviterName;
                    }
                    var invitedEmail = undefined;
                    if (this.props.thirdPartyInvite) {
                        invitedEmail = this.props.thirdPartyInvite.invitedEmail;
                    }

                    // We have no room object for this room, only the ID.
                    // We've got to this room by following a link, possibly a third party invite.
                    var room_alias = this.props.roomAddress[0] == '#' ? this.props.roomAddress : null;
                    return (
                        <div className="mx_RoomView">
                            <RoomHeader ref="header"
                                room={this.state.room}
                                oobData={this.props.oobData}
                                rightPanelCollapsed={ this.props.rightPanelCollapsed }
                            />
                            <div className="mx_RoomView_auxPanel">
                                <RoomPreviewBar onJoinClick={ this.onJoinButtonClicked }
                                                onRejectClick={ this.onRejectThreepidInviteButtonClicked }
                                                canPreview={ false } error={ this.state.roomLoadError }
                                                roomAlias={room_alias}
                                                spinner={this.state.joining}
                                                inviterName={inviterName}
                                                invitedEmail={invitedEmail}
                                                room={this.state.room}
                                />
                            </div>
                            <div className="mx_RoomView_messagePanel"></div>
                        </div>
                    );
                }
        }

        var myUserId = MatrixClientPeg.get().credentials.userId;
        var myMember = this.state.room.getMember(myUserId);
        if (myMember && myMember.membership == 'invite') {
            if (this.state.joining || this.state.rejecting) {
                return (
                    <div className="mx_RoomView">
                        <Loader />
                    </div>
                );
            } else {
                var inviteEvent = myMember.events.member;
                var inviterName = inviteEvent.sender ? inviteEvent.sender.name : inviteEvent.getSender();

                // We deliberately don't try to peek into invites, even if we have permission to peek
                // as they could be a spam vector.
                // XXX: in future we could give the option of a 'Preview' button which lets them view anyway.

                // We have a regular invite for this room.
                return (
                    <div className="mx_RoomView">
                        <RoomHeader ref="header" room={this.state.room}/>
                        <div className="mx_RoomView_auxPanel">
                            <RoomPreviewBar onJoinClick={ this.onJoinButtonClicked }
                                            onRejectClick={ this.onRejectButtonClicked }
                                            inviterName={ inviterName }
                                            canPreview={ false }
                                            spinner={this.state.joining}
                                            room={this.state.room}
                            />
                        </div>
                        <div className="mx_RoomView_messagePanel"></div>
                    </div>
                );
            }
        }

        // We have successfully loaded this room, and are not previewing.
        // Display the "normal" room view.

        var call = this._getCallForRoom();
        var inCall = false;
        if (call && (this.state.callState !== 'ended' && this.state.callState !== 'ringing')) {
            inCall = true;
        }

        var scrollheader_classes = classNames({
            mx_RoomView_scrollheader: true,
        });

        var statusBar;

        if (ContentMessages.getCurrentUploads().length > 0) {
            var UploadBar = sdk.getComponent('structures.UploadBar');
            statusBar = <UploadBar room={this.state.room} />
        } else if (!this.state.searchResults) {
            var RoomStatusBar = sdk.getComponent('structures.RoomStatusBar');

            statusBar = <RoomStatusBar
                room={this.state.room}
                tabComplete={this.tabComplete}
                numUnreadMessages={this.state.numUnreadMessages}
                hasUnsentMessages={this.state.hasUnsentMessages}
                atEndOfLiveTimeline={this.state.atEndOfLiveTimeline}
                hasActiveCall={inCall}
                onResendAllClick={this.onResendAllClick}
                onCancelAllClick={this.onCancelAllClick}
                onScrollToBottomClick={this.jumpToLiveTimeline}
                onResize={this.onChildResize}
                />
        }

        var aux = null;
        if (this.state.editingRoomSettings) {
            aux = <RoomSettings ref="room_settings" onSaveClick={this.onSettingsSaveClick} onCancelClick={this.onCancelClick} room={this.state.room} />;
        }
        else if (this.state.uploadingRoomSettings) {
            aux = <Loader/>;
        }
        else if (this.state.searching) {
            aux = <SearchBar ref="search_bar" searchInProgress={this.state.searchInProgress } onCancelClick={this.onCancelSearchClick} onSearch={this.onSearch}/>;
        }
        else if (!myMember || myMember.membership !== "join") {
            // We do have a room object for this room, but we're not currently in it.
            // We may have a 3rd party invite to it.
            var inviterName = undefined;
            if (this.props.oobData) {
                inviterName = this.props.oobData.inviterName;
            }
            var invitedEmail = undefined;
            if (this.props.thirdPartyInvite) {
                invitedEmail = this.props.thirdPartyInvite.invitedEmail;
            }
            aux = (
                <RoomPreviewBar onJoinClick={this.onJoinButtonClicked}
                                onRejectClick={this.onRejectThreepidInviteButtonClicked}
                                spinner={this.state.joining}
                                inviterName={inviterName}
                                invitedEmail={invitedEmail}
                                canPreview={this.state.canPeek}
                                room={this.state.room}
                />
            );
        }

        var auxPanel = (
            <AuxPanel ref="auxPanel" room={this.state.room}
              conferenceHandler={this.props.ConferenceHandler}
              draggingFile={this.state.draggingFile}
              displayConfCallNotification={this.state.displayConfCallNotification}
              maxHeight={this.state.auxPanelMaxHeight}
              onResize={this.onChildResize} >
                { aux }
            </AuxPanel>
        );

        var messageComposer, searchInfo;
        var canSpeak = (
            // joined and not showing search results
            myMember && (myMember.membership == 'join') && !this.state.searchResults
        );
        if (canSpeak) {
            messageComposer =
                <MessageComposer
                    room={this.state.room} onResize={this.onChildResize} uploadFile={this.uploadFile}
                    callState={this.state.callState} tabComplete={this.tabComplete} opacity={ this.props.opacity }/>
        }

        // TODO: Why aren't we storing the term/scope/count in this format
        // in this.state if this is what RoomHeader desires?
        if (this.state.searchResults) {
            searchInfo = {
                searchTerm : this.state.searchTerm,
                searchScope : this.state.searchScope,
                searchCount : this.state.searchResults.count,
            };
        }

        if (inCall) {
            var zoomButton, voiceMuteButton, videoMuteButton;

            if (call.type === "video") {
                zoomButton = (
                    <div className="mx_RoomView_voipButton" onClick={this.onFullscreenClick} title="Fill screen">
                        <TintableSvg src="img/fullscreen.svg" width="29" height="22" style={{ marginTop: 1, marginRight: 4 }}/>
                    </div>
                );

                videoMuteButton =
                    <div className="mx_RoomView_voipButton" onClick={this.onMuteVideoClick}>
                        <img src={call.isLocalVideoMuted() ? "img/video-unmute.svg" : "img/video-mute.svg"}
                             alt={call.isLocalVideoMuted() ? "Click to unmute video" : "Click to mute video"}
                             width="31" height="27"/>
                    </div>
            }
            voiceMuteButton =
                <div className="mx_RoomView_voipButton" onClick={this.onMuteAudioClick}>
                    <img src={call.isMicrophoneMuted() ? "img/voice-unmute.svg" : "img/voice-mute.svg"}
                         alt={call.isMicrophoneMuted() ? "Click to unmute audio" : "Click to mute audio"}
                         width="21" height="26"/>
                </div>

            // wrap the existing status bar into a 'callStatusBar' which adds more knobs.
            statusBar =
                <div className="mx_RoomView_callStatusBar">
                    { voiceMuteButton }
                    { videoMuteButton }
                    { zoomButton }
                    { statusBar }
                    <TintableSvg className="mx_RoomView_voipChevron" src="img/voip-chevron.svg" width="22" height="17"/>
                </div>
        }

        // if we have search results, we keep the messagepanel (so that it preserves its
        // scroll state), but hide it.
        var searchResultsPanel;
        var hideMessagePanel = false;

        if (this.state.searchResults) {
            searchResultsPanel = (
                <ScrollPanel ref="searchResultsPanel"
                    className="mx_RoomView_messagePanel mx_RoomView_searchResultsPanel"
                    onFillRequest={ this.onSearchResultsFillRequest }
                    onResize={ this.onSearchResultsResize }
                    style={{ opacity: this.props.opacity }}
                >
                    <li className={scrollheader_classes}></li>
                    {this.getSearchResultTiles()}
                </ScrollPanel>
            );
            hideMessagePanel = true;
        }

        var messagePanel = (
            <TimelinePanel ref={this._gatherTimelinePanelRef}
                room={this.state.room}
                hidden={hideMessagePanel}
                highlightedEventId={this.props.highlightedEventId}
                eventId={this.props.eventId}
                eventPixelOffset={this.props.eventPixelOffset}
                onScroll={ this.onMessageListScroll }
                onReadMarkerUpdated={ this._updateTopUnreadMessagesBar }
                opacity={ this.props.opacity }
            />);

        var topUnreadMessagesBar = null;
        if (this.state.showTopUnreadMessagesBar) {
            var TopUnreadMessagesBar = sdk.getComponent('rooms.TopUnreadMessagesBar');
            topUnreadMessagesBar = (
                <div className="mx_RoomView_topUnreadMessagesBar mx_fadable" style={{ opacity: this.props.opacity }}>
                    <TopUnreadMessagesBar
                       onScrollUpClick={this.jumpToReadMarker}
                       onCloseClick={this.forgetReadMarker}
                    />
                </div>
            );
        }

        return (
            <div className={ "mx_RoomView" + (inCall ? " mx_RoomView_inCall" : "") } ref="roomView">
                <RoomHeader ref="header" room={this.state.room} searchInfo={searchInfo}
                    oobData={this.props.oobData}
                    editing={this.state.editingRoomSettings}
                    saving={this.state.uploadingRoomSettings}
                    onSearchClick={this.onSearchClick}
                    onSettingsClick={this.onSettingsClick}
                    onSaveClick={this.onSettingsSaveClick}
                    onCancelClick={this.onCancelClick}
                    onForgetClick={
                        (myMember && myMember.membership === "leave") ? this.onForgetClick : null
                    }
                    onLeaveClick={
                        (myMember && myMember.membership === "join") ? this.onLeaveClick : null
                    } />
                { auxPanel }
                { topUnreadMessagesBar }
                { messagePanel }
                { searchResultsPanel }
                <div className="mx_RoomView_statusArea mx_fadable" style={{ opacity: this.props.opacity }}>
                    <div className="mx_RoomView_statusAreaBox">
                        <div className="mx_RoomView_statusAreaBox_line"></div>
                        { statusBar }
                    </div>
                </div>
                { messageComposer }
            </div>
        );
    },
});