/*
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.
*/

var q = require("q");
var React = require('react');
var MatrixClientPeg = require('../../../MatrixClientPeg');
var SdkConfig = require('../../../SdkConfig');
var sdk = require('../../../index');
var Modal = require('../../../Modal');
var ObjectUtils = require("../../../ObjectUtils");
var dis = require("../../../dispatcher");
var ScalarAuthClient = require("../../../ScalarAuthClient");
var UserSettingsStore = require('../../../UserSettingsStore');

// parse a string as an integer; if the input is undefined, or cannot be parsed
// as an integer, return a default.
function parseIntWithDefault(val, def) {
    var res = parseInt(val);
    return isNaN(res) ? def : res;
}

module.exports = React.createClass({
    displayName: 'RoomSettings',

    propTypes: {
        room: React.PropTypes.object.isRequired,
        onSaveClick: React.PropTypes.func,
        onCancelClick: React.PropTypes.func,
    },

    getInitialState: function() {
        var tags = {};
        Object.keys(this.props.room.tags).forEach(function(tagName) {
            tags[tagName] = ['yep'];
        });

        var areNotifsMuted = false;
        if (!MatrixClientPeg.get().isGuest()) {
            var roomPushRule = MatrixClientPeg.get().getRoomPushRule("global", this.props.room.roomId);
            if (roomPushRule) {
                if (0 <= roomPushRule.actions.indexOf("dont_notify")) {
                    areNotifsMuted = true;
                }
            }
        }

        return {
            name: this._yankValueFromEvent("m.room.name", "name"),
            topic: this._yankValueFromEvent("m.room.topic", "topic"),
            join_rule: this._yankValueFromEvent("m.room.join_rules", "join_rule"),
            history_visibility: this._yankValueFromEvent("m.room.history_visibility", "history_visibility"),
            guest_access: this._yankValueFromEvent("m.room.guest_access", "guest_access"),
            power_levels_changed: false,
            tags_changed: false,
            tags: tags,
            areNotifsMuted: areNotifsMuted,
            // isRoomPublished is loaded async in componentWillMount so when the component
            // inits, the saved value will always be undefined, however getInitialState()
            // is also called from the saving code so we must return the correct value here
            // if we have it (although this could race if the user saves before we load whether
            // the room is published or not).
            // Default to false if it's undefined, otherwise react complains about changing
            // components from uncontrolled to controlled
            isRoomPublished: this._originalIsRoomPublished || false,
            scalar_token: null,
            scalar_error: null,
        };
    },

    componentWillMount: function() {
        MatrixClientPeg.get().getRoomDirectoryVisibility(
            this.props.room.roomId
        ).done((result) => {
            this.setState({ isRoomPublished: result.visibility === "public" });
            this._originalIsRoomPublished = result.visibility === "public";
        }, (err) => {
            console.error("Failed to get room visibility: " + err);
        });

        this.getScalarToken().done((token) => {
            this.setState({scalar_token: token});
        }, (err) => {
            this.setState({scalar_error: err});
        });

        dis.dispatch({
            action: 'ui_opacity',
            sideOpacity: 0.3,
            middleOpacity: 0.3,
        });
    },

    componentWillUnmount: function() {
        dis.dispatch({
            action: 'ui_opacity',
            sideOpacity: 1.0,
            middleOpacity: 1.0,
        });
    },

    setName: function(name) {
        this.setState({
            name: name
        });
    },

    setTopic: function(topic) {
        this.setState({
            topic: topic
        });
    },

    save: function() {
        var stateWasSetDefer = q.defer();
        // the caller may have JUST called setState on stuff, so we need to re-render before saving
        // else we won't use the latest values of things.
        // We can be a bit cheeky here and set a loading flag, and listen for the callback on that
        // to know when things have been set.
        this.setState({ _loading: true}, () => {
            stateWasSetDefer.resolve();
            this.setState({ _loading: false});
        });

        return stateWasSetDefer.promise.then(() => {
            return this._save();
        });
    },

    _save: function() {
        const roomId = this.props.room.roomId;
        var promises = this.saveAliases(); // returns Promise[]
        var originalState = this.getInitialState();

        // diff between original state and this.state to work out what has been changed
        console.log("Original: %s", JSON.stringify(originalState));
        console.log("New: %s", JSON.stringify(this.state));

        // name and topic
        if (this._hasDiff(this.state.name, originalState.name)) {
            promises.push(MatrixClientPeg.get().setRoomName(roomId, this.state.name));
        }
        if (this._hasDiff(this.state.topic, originalState.topic)) {
            promises.push(MatrixClientPeg.get().setRoomTopic(roomId, this.state.topic));
        }

        if (this.state.history_visibility !== originalState.history_visibility) {
            promises.push(MatrixClientPeg.get().sendStateEvent(
                roomId, "m.room.history_visibility",
                { history_visibility: this.state.history_visibility },
                ""
            ));
        }

        if (this.state.isRoomPublished !== originalState.isRoomPublished) {
            promises.push(MatrixClientPeg.get().setRoomDirectoryVisibility(
                roomId,
                this.state.isRoomPublished ? "public" : "private"
            ));
        }

        if (this.state.join_rule !== originalState.join_rule) {
            promises.push(MatrixClientPeg.get().sendStateEvent(
                roomId, "m.room.join_rules",
                { join_rule: this.state.join_rule },
                ""
            ));
        }

        if (this.state.guest_access !== originalState.guest_access) {
            promises.push(MatrixClientPeg.get().sendStateEvent(
                roomId, "m.room.guest_access",
                { guest_access: this.state.guest_access },
                ""
            ));
        }


        if (this.state.areNotifsMuted !== originalState.areNotifsMuted) {
            promises.push(MatrixClientPeg.get().setRoomMutePushRule(
                "global", roomId, this.state.areNotifsMuted
            ));
        }

        // power levels
        var powerLevels = this._getPowerLevels();
        if (powerLevels) {
            promises.push(MatrixClientPeg.get().sendStateEvent(
                roomId, "m.room.power_levels", powerLevels, ""
            ));
        }

        // tags
        if (this.state.tags_changed) {
            var tagDiffs = ObjectUtils.getKeyValueArrayDiffs(originalState.tags, this.state.tags);
            // [ {place: add, key: "m.favourite", val: ["yep"]} ]
            tagDiffs.forEach(function(diff) {
                switch (diff.place) {
                    case "add":
                        promises.push(
                            MatrixClientPeg.get().setRoomTag(roomId, diff.key, {})
                        );
                        break;
                    case "del":
                        promises.push(
                            MatrixClientPeg.get().deleteRoomTag(roomId, diff.key)
                        );
                        break;
                    default:
                        console.error("Unknown tag operation: %s", diff.place);
                        break;
                }
            });
        }

        // color scheme
        promises.push(this.saveColor());

        // url preview settings
        promises.push(this.saveUrlPreviewSettings());

        // encryption
        promises.push(this.saveEncryption());

        console.log("Performing %s operations: %s", promises.length, JSON.stringify(promises));
        return q.allSettled(promises);
    },

    saveAliases: function() {
        if (!this.refs.alias_settings) { return [q()]; }
        return this.refs.alias_settings.saveSettings();
    },

    saveColor: function() {
        if (!this.refs.color_settings) { return q(); }
        return this.refs.color_settings.saveSettings();
    },

    saveUrlPreviewSettings: function() {
        if (!this.refs.url_preview_settings) { return q(); }
        return this.refs.url_preview_settings.saveSettings();
    },

    saveEncryption: function () {
        if (!this.refs.encrypt) { return q(); }

        var encrypt = this.refs.encrypt.checked;
        if (!encrypt) { return q(); }

        var roomId = this.props.room.roomId;
        return MatrixClientPeg.get().sendStateEvent(
            roomId, "m.room.encryption",
            { algorithm: "m.olm.v1.curve25519-aes-sha2" }
        );
    },

    _hasDiff: function(strA, strB) {
        // treat undefined as an empty string because other components may blindly
        // call setName("") when there has been no diff made to the name!
        strA = strA || "";
        strB = strB || "";
        return strA !== strB;
    },

    _getPowerLevels: function() {
        if (!this.state.power_levels_changed) return undefined;

        var powerLevels = this.props.room.currentState.getStateEvents('m.room.power_levels', '');
        powerLevels = powerLevels ? powerLevels.getContent() : {};

        var newPowerLevels = {
            ban: parseInt(this.refs.ban.getValue()),
            kick: parseInt(this.refs.kick.getValue()),
            redact: parseInt(this.refs.redact.getValue()),
            invite: parseInt(this.refs.invite.getValue()),
            events_default: parseInt(this.refs.events_default.getValue()),
            state_default: parseInt(this.refs.state_default.getValue()),
            users_default: parseInt(this.refs.users_default.getValue()),
            users: powerLevels.users,
            events: powerLevels.events,
        };

        return newPowerLevels;
    },

    onPowerLevelsChanged: function() {
        this.setState({
            power_levels_changed: true
        });
    },

    _yankValueFromEvent: function(stateEventType, keyName, defaultValue) {
        // E.g.("m.room.name","name") would yank the "name" content key from "m.room.name"
        var event = this.props.room.currentState.getStateEvents(stateEventType, '');
        if (!event) {
            return defaultValue;
        }
        return event.getContent()[keyName] || defaultValue;
    },

    _onHistoryRadioToggle: function(ev) {
        var self = this;
        var QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");

        // cancel the click unless the user confirms it
        ev.preventDefault();
        var value = ev.target.value;

        Modal.createDialog(QuestionDialog, {
            title: "Privacy warning",
            description:
                <div>
                    Changes to who can read history will only apply to future messages in this room.<br/>
                    The visibility of existing history will be unchanged.
                </div>,
            button: "Continue",
            onFinished: function(confirmed) {
                if (confirmed) {
                    self.setState({
                        history_visibility: value
                    });
                }
            },
        });
    },

    _onRoomAccessRadioToggle: function(ev) {

        //                         join_rule
        //                      INVITE  |  PUBLIC
        //        ----------------------+----------------
        // guest  CAN_JOIN   | inv_only | pub_with_guest
        // access ----------------------+----------------
        //        FORBIDDEN  | inv_only | pub_no_guest
        //        ----------------------+----------------

        switch (ev.target.value) {
            case "invite_only":
                this.setState({
                    join_rule: "invite",
                    // we always set guests can_join here as it makes no sense to have
                    // an invite-only room that guests can't join.  If you explicitly
                    // invite them, you clearly want them to join, whether they're a
                    // guest or not.  In practice, guest_access should probably have
                    // been implemented as part of the join_rules enum.
                    guest_access: "can_join",
                });
                break;
            case "public_no_guests":
                this.setState({
                    join_rule: "public",
                    guest_access: "forbidden",
                });
                break;
            case "public_with_guests":
                this.setState({
                    join_rule: "public",
                    guest_access: "can_join",
                });
                break;
        }
    },

    _onToggle: function(keyName, checkedValue, uncheckedValue, ev) {
        console.log("Checkbox toggle: %s %s", keyName, ev.target.checked);
        var state = {};
        state[keyName] = ev.target.checked ? checkedValue : uncheckedValue;
        this.setState(state);
    },

    _onTagChange: function(tagName, event) {
        if (event.target.checked) {
            if (tagName === 'm.favourite') {
                delete this.state.tags['m.lowpriority'];
            }
            else if (tagName === 'm.lowpriority') {
                delete this.state.tags['m.favourite'];
            }

            this.state.tags[tagName] = this.state.tags[tagName] || ["yep"];
        }
        else {
            delete this.state.tags[tagName];
        }

        this.setState({
            tags: this.state.tags,
            tags_changed: true
        });
    },

    mayChangeRoomAccess: function() {
        var cli = MatrixClientPeg.get();
        var roomState = this.props.room.currentState;
        return (roomState.mayClientSendStateEvent("m.room.join_rules", cli) &&
                roomState.mayClientSendStateEvent("m.room.guest_access", cli))
    },

    getScalarInterfaceUrl: function() {
        var url = SdkConfig.get().integrations_ui_url;
        url += "?scalar_token=" + encodeURIComponent(this.state.scalar_token);
        url += "&room_id=" + encodeURIComponent(this.props.room.roomId);
        return url;
    },

    getScalarToken() {
        var tok = window.localStorage.getItem("mx_scalar_token");
        if (tok) return q(tok);

        // No saved token, so do the dance to get one. First, we
        // need an openid bearer token from the HS.
        return MatrixClientPeg.get().getOpenIdToken().then((token_object) => {
            // Now we can send that to scalar and exchange it for a scalar token
            var scalar_auth_client = new ScalarAuthClient();
            return scalar_auth_client.getScalarToken(token_object);
        }).then((token_object) => {
            window.localStorage.setItem("mx_scalar_token", token_object);
            return token_object;
        });
    },

    onManageIntegrations(ev) {
        ev.preventDefault();
        var IntegrationsManager = sdk.getComponent("views.settings.IntegrationsManager");
        Modal.createDialog(IntegrationsManager, {
            src: this.state.scalar_token ? this.getScalarInterfaceUrl() : null
        }, "");
    },

    _renderEncryptionSection: function() {
        if (!UserSettingsStore.isFeatureEnabled("e2e_encryption")) {
            return null;
        }

        var cli = MatrixClientPeg.get();
        var roomState = this.props.room.currentState;
        var isEncrypted = cli.isRoomEncrypted(this.props.room.roomId);

        var text = "Encryption is " + (isEncrypted ? "" : "not ") +
            "enabled in this room.";

        var button;
        if (!isEncrypted &&
                roomState.mayClientSendStateEvent("m.room.encryption", cli)) {
            button = (
                <label>
                    <input type="checkbox" ref="encrypt" />
                    Enable encryption (warning: cannot be disabled again!)
                </label>
            );
        }

        return (
            <div className="mx_RoomSettings_toggles">
                <h3>Encryption</h3>
                <label>{text}</label>
                {button}
            </div>
        );
    },

    render: function() {
        // TODO: go through greying out things you don't have permission to change
        // (or turning them into informative stuff)

        var AliasSettings = sdk.getComponent("room_settings.AliasSettings");
        var ColorSettings = sdk.getComponent("room_settings.ColorSettings");
        var UrlPreviewSettings = sdk.getComponent("room_settings.UrlPreviewSettings");
        var EditableText = sdk.getComponent('elements.EditableText');
        var PowerSelector = sdk.getComponent('elements.PowerSelector');
        var Loader = sdk.getComponent("elements.Spinner")

        var cli = MatrixClientPeg.get();
        var roomState = this.props.room.currentState;
        var user_id = cli.credentials.userId;

        var power_level_event = roomState.getStateEvents('m.room.power_levels', '');
        var power_levels = power_level_event ? power_level_event.getContent() : {};
        var events_levels = power_levels.events || {};
        var user_levels = power_levels.users || {};

        var ban_level = parseIntWithDefault(power_levels.ban, 50);
        var kick_level = parseIntWithDefault(power_levels.kick, 50);
        var redact_level = parseIntWithDefault(power_levels.redact, 50);
        var invite_level = parseIntWithDefault(power_levels.invite, 50);
        var send_level = parseIntWithDefault(power_levels.events_default, 0);
        var state_level = power_level_event ? parseIntWithDefault(power_levels.state_default, 50) : 0;
        var default_user_level = parseIntWithDefault(power_levels.users_default, 0);

        var current_user_level = user_levels[user_id];
        if (current_user_level === undefined) {
            current_user_level = default_user_level;
        }

        var can_change_levels = roomState.mayClientSendStateEvent("m.room.power_levels", cli);

        var canSetTag = !cli.isGuest();

        var self = this;

        var userLevelsSection;
        if (Object.keys(user_levels).length) {
            userLevelsSection =
                <div>
                    <h3>Privileged Users</h3>
                    <ul className="mx_RoomSettings_userLevels">
                        {Object.keys(user_levels).map(function(user, i) {
                            return (
                                <li className="mx_RoomSettings_userLevel" key={user}>
                                    { user } is a <PowerSelector value={ user_levels[user] } disabled={true}/>
                                </li>
                            );
                        })}
                    </ul>
                </div>;
        }
        else {
            userLevelsSection = <div>No users have specific privileges in this room.</div>
        }

        var banned = this.props.room.getMembersWithMembership("ban");
        var bannedUsersSection;
        if (banned.length) {
            bannedUsersSection =
                <div>
                    <h3>Banned users</h3>
                    <ul className="mx_RoomSettings_banned">
                        {banned.map(function(member, i) {
                            return (
                                <li key={i}>
                                    {member.userId}
                                </li>
                            );
                        })}
                    </ul>
                </div>;
        }

        var unfederatableSection;
        if (this._yankValueFromEvent("m.room.create", "m.federate") === false) {
             unfederatableSection = (
                <div className="mx_RoomSettings_powerLevel">
                Ths room is not accessible by remote Matrix servers.
                </div>
            );
        }

        // TODO: support editing custom events_levels
        // TODO: support editing custom user_levels

        var tags = [
            { name: "m.favourite", label: "Favourite", ref: "tag_favourite" },
            { name: "m.lowpriority", label: "Low priority", ref: "tag_lowpriority" },
        ];

        Object.keys(this.state.tags).sort().forEach(function(tagName) {
            if (tagName !== 'm.favourite' && tagName !== 'm.lowpriority') {
                tags.push({ name: tagName, label: tagName });
            }
        });

        var tagsSection = null;
        if (canSetTag || self.state.tags) {
            var tagsSection =
                <div className="mx_RoomSettings_tags">
                    Tagged as: { canSetTag ?
                        (tags.map(function(tag, i) {
                            return (<label key={ i }>
                                        <input type="checkbox"
                                               ref={ tag.ref }
                                               checked={ tag.name in self.state.tags }
                                               onChange={ self._onTagChange.bind(self, tag.name) }/>
                                        { tag.label }
                                    </label>);
                        })) : (self.state.tags && self.state.tags.join) ? self.state.tags.join(", ") : ""
                    }
                </div>
        }

        // If there is no history_visibility, it is assumed to be 'shared'.
        // http://matrix.org/docs/spec/r0.0.0/client_server.html#id31
        var historyVisibility = this.state.history_visibility || "shared";

        var addressWarning;
        var aliasEvents = this.props.room.currentState.getStateEvents('m.room.aliases') || [];
        var aliasCount = 0;
        aliasEvents.forEach((event) => {
            aliasCount += event.getContent().aliases.length;
        });

        if (this.state.join_rule === "public" && aliasCount == 0) {
            addressWarning =
                <div className="mx_RoomSettings_warning">
                    To link to a room it must have <a href="#addresses">an address</a>.
                </div>
        }

        var inviteGuestWarning;
        if (this.state.join_rule !== "public" && this.state.guest_access === "forbidden") {
            inviteGuestWarning =
                <div className="mx_RoomSettings_warning">
                    Guests cannot join this room even if explicitly invited. <a href="#" onClick={ (e) => {
                        this.setState({ join_rule: "invite", guest_access: "can_join" });
                        e.preventDefault();
                    }}>Click here to fix</a>.
                </div>
        }

        var integrations_section;
        if (UserSettingsStore.isFeatureEnabled("integration_management")) {
            let integrations_body;

            if (this.state.scalar_token) {
                integrations_body = (
                    <div className="mx_RoomSettings_settings">
                        <a href="#" onClick={ this.onManageIntegrations }>Manage integrations</a>
                    </div>
                );
            } else if (this.state.scalar_error) {
                integrations_body = <div className="error">
                    Unable to contact integrations server
                </div>;
            } else {
                integrations_body = <Loader />;
            }
            integrations_section = <div>
                <h3>Integrations</h3>
                {integrations_body}
            </div>;
        }

        return (
            <div className="mx_RoomSettings">

                { tagsSection }

                <div className="mx_RoomSettings_toggles">
                    <label>
                        <input type="checkbox" disabled={ cli.isGuest() }
                               onChange={this._onToggle.bind(this, "areNotifsMuted", true, false)}
                               defaultChecked={this.state.areNotifsMuted}/>
                        'Mention only' notifications for this room
                    </label>
                    <div className="mx_RoomSettings_settings">
                        <h3>Who can access this room?</h3>
                        { inviteGuestWarning }
                        <label>
                            <input type="radio" name="roomVis" value="invite_only"
                                disabled={ !this.mayChangeRoomAccess() }
                                onChange={this._onRoomAccessRadioToggle}
                                checked={this.state.join_rule !== "public"}/>
                            Only people who have been invited
                        </label>
                        <label>
                            <input type="radio" name="roomVis" value="public_no_guests"
                                disabled={ !this.mayChangeRoomAccess() }
                                onChange={this._onRoomAccessRadioToggle}
                                checked={this.state.join_rule === "public" && this.state.guest_access !== "can_join"}/>
                            Anyone who knows the room's link, apart from guests
                        </label>
                        <label>
                            <input type="radio" name="roomVis" value="public_with_guests"
                                disabled={ !this.mayChangeRoomAccess() }
                                onChange={this._onRoomAccessRadioToggle}
                                checked={this.state.join_rule === "public" && this.state.guest_access === "can_join"}/>
                            Anyone who knows the room's link, including guests
                        </label>
                        { addressWarning }
                        <br/>
                        <label>
                            <input type="checkbox" disabled={ !roomState.mayClientSendStateEvent("m.room.aliases", cli) }
                                   onChange={ this._onToggle.bind(this, "isRoomPublished", true, false)}
                                   checked={this.state.isRoomPublished}/>
                            List this room in { MatrixClientPeg.get().getDomain() }'s room directory?
                        </label>
                    </div>
                    <div className="mx_RoomSettings_settings">
                        <h3>Who can read history?</h3>
                        <label>
                            <input type="radio" name="historyVis" value="world_readable"
                                    disabled={ !roomState.mayClientSendStateEvent("m.room.history_visibility", cli) }
                                    checked={historyVisibility === "world_readable"}
                                    onChange={this._onHistoryRadioToggle} />
                            Anyone
                        </label>
                        <label>
                            <input type="radio" name="historyVis" value="shared"
                                    disabled={ !roomState.mayClientSendStateEvent("m.room.history_visibility", cli) }
                                    checked={historyVisibility === "shared"}
                                    onChange={this._onHistoryRadioToggle} />
                            Members only (since the point in time of selecting this option)
                        </label>
                        <label>
                            <input type="radio" name="historyVis" value="invited"
                                    disabled={ !roomState.mayClientSendStateEvent("m.room.history_visibility", cli) }
                                    checked={historyVisibility === "invited"}
                                    onChange={this._onHistoryRadioToggle} />
                            Members only (since they were invited)
                        </label>
                        <label >
                            <input type="radio" name="historyVis" value="joined"
                                    disabled={ !roomState.mayClientSendStateEvent("m.room.history_visibility", cli) }
                                    checked={historyVisibility === "joined"}
                                    onChange={this._onHistoryRadioToggle} />
                            Members only (since they joined)
                        </label>
                    </div>
                </div>


                <div>
                    <h3>Room Colour</h3>
                    <ColorSettings ref="color_settings" room={this.props.room} />
                </div>

                { integrations_section }

                <a id="addresses"/>

                <AliasSettings ref="alias_settings"
                    roomId={this.props.room.roomId}
                    canSetCanonicalAlias={ roomState.mayClientSendStateEvent("m.room.canonical_alias", cli) }
                    canSetAliases={ roomState.mayClientSendStateEvent("m.room.aliases", cli) }
                    canonicalAliasEvent={this.props.room.currentState.getStateEvents('m.room.canonical_alias', '')}
                    aliasEvents={this.props.room.currentState.getStateEvents('m.room.aliases')} />

                <UrlPreviewSettings ref="url_preview_settings" room={this.props.room} />

                <h3>Permissions</h3>
                <div className="mx_RoomSettings_powerLevels mx_RoomSettings_settings">
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">The default role for new room members is </span>
                        <PowerSelector ref="users_default" value={default_user_level} controlled={false} disabled={!can_change_levels || current_user_level < default_user_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To send messages, you must be a </span>
                        <PowerSelector ref="events_default" value={send_level} controlled={false} disabled={!can_change_levels || current_user_level < send_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To invite users into the room, you must be a </span>
                        <PowerSelector ref="invite" value={invite_level} controlled={false} disabled={!can_change_levels || current_user_level < invite_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To configure the room, you must be a </span>
                        <PowerSelector ref="state_default" value={state_level} controlled={false} disabled={!can_change_levels || current_user_level < state_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To kick users, you must be a </span>
                        <PowerSelector ref="kick" value={kick_level} controlled={false} disabled={!can_change_levels || current_user_level < kick_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To ban users, you must be a </span>
                        <PowerSelector ref="ban" value={ban_level} controlled={false} disabled={!can_change_levels || current_user_level < ban_level} onChange={this.onPowerLevelsChanged}/>
                    </div>
                    <div className="mx_RoomSettings_powerLevel">
                        <span className="mx_RoomSettings_powerLevelKey">To redact messages, you must be a </span>
                        <PowerSelector ref="redact" value={redact_level} controlled={false} disabled={!can_change_levels || current_user_level < redact_level} onChange={this.onPowerLevelsChanged}/>
                    </div>

                    {Object.keys(events_levels).map(function(event_type, i) {
                        return (
                            <div className="mx_RoomSettings_powerLevel" key={event_type}>
                                <span className="mx_RoomSettings_powerLevelKey">To send events of type <code>{ event_type }</code>, you must be a </span>
                                <PowerSelector value={ events_levels[event_type] } controlled={false} disabled={true} onChange={self.onPowerLevelsChanged}/>
                            </div>
                        );
                    })}

                { unfederatableSection }
                </div>

                { userLevelsSection }

                { bannedUsersSection }

                { this._renderEncryptionSection() }

                <h3>Advanced</h3>
                <div className="mx_RoomSettings_settings">
                    This room's internal ID is <code>{ this.props.room.roomId }</code>
                </div>
            </div>
        );
    }
});