element-web/src/components/views/dialogs/DMInviteDialog.js

/*
Copyright 2019, 2020 The Matrix.org Foundation C.I.C.

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.
*/

import React, {createRef} from 'react';
import PropTypes from 'prop-types';
import {_t} from "../../../languageHandler";
import * as sdk from "../../../index";
import {MatrixClientPeg} from "../../../MatrixClientPeg";
import {makeUserPermalink} from "../../../utils/permalinks/Permalinks";
import DMRoomMap from "../../../utils/DMRoomMap";
import {RoomMember} from "matrix-js-sdk/src/matrix";
import SdkConfig from "../../../SdkConfig";
import {getHttpUriForMxc} from "matrix-js-sdk/src/content-repo";
import * as Email from "../../../email";
import {getDefaultIdentityServerUrl, useDefaultIdentityServer} from "../../../utils/IdentityServerUtils";
import {abbreviateUrl} from "../../../utils/UrlUtils";
import dis from "../../../dispatcher";
import IdentityAuthClient from "../../../IdentityAuthClient";
import Modal from "../../../Modal";
import {humanizeTime} from "../../../utils/humanize";
import createRoom from "../../../createRoom";
import {inviteMultipleToRoom} from "../../../RoomInvite";

// TODO: [TravisR] Make this generic for all kinds of invites

const INITIAL_ROOMS_SHOWN = 3; // Number of rooms to show at first
const INCREMENT_ROOMS_SHOWN = 5; // Number of rooms to add when 'show more' is clicked

// This is the interface that is expected by various components in this file. It is a bit
// awkward because it also matches the RoomMember class from the js-sdk with some extra support
// for 3PIDs/email addresses.
//
// XXX: We should use TypeScript interfaces instead of this weird "abstract" class.
class Member {
    /**
     * The display name of this Member. For users this should be their profile's display
     * name or user ID if none set. For 3PIDs this should be the 3PID address (email).
     */
    get name(): string { throw new Error("Member class not implemented"); }

    /**
     * The ID of this Member. For users this should be their user ID. For 3PIDs this should
     * be the 3PID address (email).
     */
    get userId(): string { throw new Error("Member class not implemented"); }

    /**
     * Gets the MXC URL of this Member's avatar. For users this should be their profile's
     * avatar MXC URL or null if none set. For 3PIDs this should always be null.
     */
    getMxcAvatarUrl(): string { throw new Error("Member class not implemented"); }
}

class DirectoryMember extends Member {
    _userId: string;
    _displayName: string;
    _avatarUrl: string;

    constructor(userDirResult: {user_id: string, display_name: string, avatar_url: string}) {
        super();
        this._userId = userDirResult.user_id;
        this._displayName = userDirResult.display_name;
        this._avatarUrl = userDirResult.avatar_url;
    }

    // These next class members are for the Member interface
    get name(): string {
        return this._displayName || this._userId;
    }

    get userId(): string {
        return this._userId;
    }

    getMxcAvatarUrl(): string {
        return this._avatarUrl;
    }
}

class ThreepidMember extends Member {
    _id: string;

    constructor(id: string) {
        super();
        this._id = id;
    }

    // This is a getter that would be falsey on all other implementations. Until we have
    // better type support in the react-sdk we can use this trick to determine the kind
    // of 3PID we're dealing with, if any.
    get isEmail(): boolean {
        return this._id.includes('@');
    }

    // These next class members are for the Member interface
    get name(): string {
        return this._id;
    }

    get userId(): string {
        return this._id;
    }

    getMxcAvatarUrl(): string {
        return null;
    }
}

class DMUserTile extends React.PureComponent {
    static propTypes = {
        member: PropTypes.object.isRequired, // Should be a Member (see interface above)
        onRemove: PropTypes.func.isRequired, // takes 1 argument, the member being removed
    };

    _onRemove = (e) => {
        // Stop the browser from highlighting text
        e.preventDefault();
        e.stopPropagation();

        this.props.onRemove(this.props.member);
    };

    render() {
        const BaseAvatar = sdk.getComponent("views.avatars.BaseAvatar");
        const AccessibleButton = sdk.getComponent("elements.AccessibleButton");

        const avatarSize = 20;
        const avatar = this.props.member.isEmail
            ? <img
                className='mx_DMInviteDialog_userTile_avatar mx_DMInviteDialog_userTile_threepidAvatar'
                src={require("../../../../res/img/icon-email-pill-avatar.svg")}
                width={avatarSize} height={avatarSize} />
            : <BaseAvatar
                className='mx_DMInviteDialog_userTile_avatar'
                url={getHttpUriForMxc(
                    MatrixClientPeg.get().getHomeserverUrl(), this.props.member.getMxcAvatarUrl(),
                    avatarSize, avatarSize, "crop")}
                name={this.props.member.name}
                idName={this.props.member.userId}
                width={avatarSize}
                height={avatarSize} />;

        return (
            <span className='mx_DMInviteDialog_userTile'>
                <span className='mx_DMInviteDialog_userTile_pill'>
                    {avatar}
                    <span className='mx_DMInviteDialog_userTile_name'>{this.props.member.name}</span>
                </span>
                <AccessibleButton
                    className='mx_DMInviteDialog_userTile_remove'
                    onClick={this._onRemove}
                >
                    <img src={require("../../../../res/img/icon-pill-remove.svg")} alt={_t('Remove')} width={8} height={8} />
                </AccessibleButton>
            </span>
        );
    }
}

class DMRoomTile extends React.PureComponent {
    static propTypes = {
        member: PropTypes.object.isRequired, // Should be a Member (see interface above)
        lastActiveTs: PropTypes.number,
        onToggle: PropTypes.func.isRequired, // takes 1 argument, the member being toggled
        highlightWord: PropTypes.string,
        isSelected: PropTypes.bool,
    };

    _onClick = (e) => {
        // Stop the browser from highlighting text
        e.preventDefault();
        e.stopPropagation();

        this.props.onToggle(this.props.member);
    };

    _highlightName(str: string) {
        if (!this.props.highlightWord) return str;

        // We convert things to lowercase for index searching, but pull substrings from
        // the submitted text to preserve case. Note: we don't need to htmlEntities the
        // string because React will safely encode the text for us.
        const lowerStr = str.toLowerCase();
        const filterStr = this.props.highlightWord.toLowerCase();

        const result = [];

        let i = 0;
        let ii;
        while ((ii = lowerStr.indexOf(filterStr, i)) >= 0) {
            // Push any text we missed (first bit/middle of text)
            if (ii > i) {
                // Push any text we aren't highlighting (middle of text match, or beginning of text)
                result.push(<span key={i + 'begin'}>{str.substring(i, ii)}</span>);
            }

            i = ii; // copy over ii only if we have a match (to preserve i for end-of-text matching)

            // Highlight the word the user entered
            const substr = str.substring(i, filterStr.length + i);
            result.push(<span className='mx_DMInviteDialog_roomTile_highlight' key={i + 'bold'}>{substr}</span>);
            i += substr.length;
        }

        // Push any text we missed (end of text)
        if (i < (str.length - 1)) {
            result.push(<span key={i + 'end'}>{str.substring(i)}</span>);
        }

        return result;
    }

    render() {
        const BaseAvatar = sdk.getComponent("views.avatars.BaseAvatar");

        let timestamp = null;
        if (this.props.lastActiveTs) {
            const humanTs = humanizeTime(this.props.lastActiveTs);
            timestamp = <span className='mx_DMInviteDialog_roomTile_time'>{humanTs}</span>;
        }

        const avatarSize = 36;
        const avatar = this.props.member.isEmail
            ? <img
                src={require("../../../../res/img/icon-email-pill-avatar.svg")}
                width={avatarSize} height={avatarSize} />
            : <BaseAvatar
                url={getHttpUriForMxc(
                    MatrixClientPeg.get().getHomeserverUrl(), this.props.member.getMxcAvatarUrl(),
                    avatarSize, avatarSize, "crop")}
                name={this.props.member.name}
                idName={this.props.member.userId}
                width={avatarSize}
                height={avatarSize} />;

        let checkmark = null;
        if (this.props.isSelected) {
            // To reduce flickering we put the 'selected' room tile above the real avatar
            checkmark = <div className='mx_DMInviteDialog_roomTile_selected' />;
        }

        // To reduce flickering we put the checkmark on top of the actual avatar (prevents
        // the browser from reloading the image source when the avatar remounts).
        const stackedAvatar = (
            <span className='mx_DMInviteDialog_roomTile_avatarStack'>
                {avatar}
                {checkmark}
            </span>
        );

        return (
            <div className='mx_DMInviteDialog_roomTile' onClick={this._onClick}>
                {stackedAvatar}
                <span className='mx_DMInviteDialog_roomTile_name'>{this._highlightName(this.props.member.name)}</span>
                <span className='mx_DMInviteDialog_roomTile_userId'>{this._highlightName(this.props.member.userId)}</span>
                {timestamp}
            </div>
        );
    }
}

export default class DMInviteDialog extends React.PureComponent {
    static propTypes = {
        // Takes an array of user IDs/emails to invite.
        onFinished: PropTypes.func.isRequired,
    };

    _debounceTimer: number = null;
    _editorRef: any = null;

    constructor() {
        super();

        this.state = {
            targets: [], // array of Member objects (see interface above)
            filterText: "",
            recents: this._buildRecents(),
            numRecentsShown: INITIAL_ROOMS_SHOWN,
            suggestions: this._buildSuggestions(),
            numSuggestionsShown: INITIAL_ROOMS_SHOWN,
            serverResultsMixin: [], // { user: DirectoryMember, userId: string }[], like recents and suggestions
            threepidResultsMixin: [], // { user: ThreepidMember, userId: string}[], like recents and suggestions
            canUseIdentityServer: !!MatrixClientPeg.get().getIdentityServerUrl(),
            tryingIdentityServer: false,

            // These two flags are used for the 'Go' button to communicate what is going on.
            busy: false,
            errorText: null,
        };

        this._editorRef = createRef();
    }

    _buildRecents(): {userId: string, user: RoomMember, lastActive: number} {
        const rooms = DMRoomMap.shared().getUniqueRoomsWithIndividuals();
        const recents = [];
        for (const userId in rooms) {
            const room = rooms[userId];
            const member = room.getMember(userId);
            if (!member) continue; // just skip people who don't have memberships for some reason

            const lastEventTs = room.timeline && room.timeline.length
                ? room.timeline[room.timeline.length - 1].getTs()
                : 0;
            if (!lastEventTs) continue; // something weird is going on with this room

            recents.push({userId, user: member, lastActive: lastEventTs});
        }

        // Sort the recents by last active to save us time later
        recents.sort((a, b) => b.lastActive - a.lastActive);

        return recents;
    }

    _buildSuggestions(): {userId: string, user: RoomMember} {
        const maxConsideredMembers = 200;
        const client = MatrixClientPeg.get();
        const excludedUserIds = [client.getUserId(), SdkConfig.get()['welcomeUserId']];
        const joinedRooms = client.getRooms()
            .filter(r => r.getMyMembership() === 'join')
            .filter(r => r.getJoinedMemberCount() <= maxConsideredMembers);

        // Generates { userId: {member, rooms[]} }
        const memberRooms = joinedRooms.reduce((members, room) => {
            // Filter out DMs (we'll handle these in the recents section)
            if (DMRoomMap.shared().getUserIdForRoomId(room.roomId)) {
                return members; // Do nothing
            }

            const joinedMembers = room.getJoinedMembers().filter(u => !excludedUserIds.includes(u.userId));
            for (const member of joinedMembers) {
                if (!members[member.userId]) {
                    members[member.userId] = {
                        member: member,
                        // Track the room size of the 'picked' member so we can use the profile of
                        // the smallest room (likely a DM).
                        pickedMemberRoomSize: room.getJoinedMemberCount(),
                        rooms: [],
                    };
                }

                members[member.userId].rooms.push(room);

                if (room.getJoinedMemberCount() < members[member.userId].pickedMemberRoomSize) {
                    members[member.userId].member = member;
                    members[member.userId].pickedMemberRoomSize = room.getJoinedMemberCount();
                }
            }
            return members;
        }, {});

        // Generates { userId: {member, numRooms, score} }
        const memberScores = Object.values(memberRooms).reduce((scores, entry) => {
            const numMembersTotal = entry.rooms.reduce((c, r) => c + r.getJoinedMemberCount(), 0);
            const maxRange = maxConsideredMembers * entry.rooms.length;
            scores[entry.member.userId] = {
                member: entry.member,
                numRooms: entry.rooms.length,
                score: Math.max(0, Math.pow(1 - (numMembersTotal / maxRange), 5)),
            };
            return scores;
        }, {});

        const members = Object.values(memberScores);
        members.sort((a, b) => {
            if (a.score === b.score) {
                if (a.numRooms === b.numRooms) {
                    return a.member.userId.localeCompare(b.member.userId);
                }

                return b.numRooms - a.numRooms;
            }
            return b.score - a.score;
        });

        return members.map(m => ({userId: m.member.userId, user: m.member}));
    }

    _startDm = () => {
        this.setState({busy: true});
        const targetIds = this.state.targets.map(t => t.userId);

        // Check if there is already a DM with these people and reuse it if possible.
        const existingRoom = DMRoomMap.shared().getDMRoomForIdentifiers(targetIds);
        if (existingRoom) {
            dis.dispatch({
                action: 'view_room',
                room_id: existingRoom.roomId,
                should_peek: false,
                joining: false,
            });
            this.props.onFinished();
            return;
        }

        // Check if it's a traditional DM and create the room if required.
        // TODO: [Canonical DMs] Remove this check and instead just create the multi-person DM
        let createRoomPromise = Promise.resolve();
        if (targetIds.length === 1) {
            createRoomPromise = createRoom({dmUserId: targetIds[0]});
        } else {
            // Create a boring room and try to invite the targets manually.
            createRoomPromise = createRoom().then(roomId => {
                return inviteMultipleToRoom(roomId, targetIds);
            }).then(result => {
                const failedUsers = Object.keys(result.states).filter(a => result.states[a] === 'error');
                if (failedUsers.length > 0) {
                    console.log("Failed to invite users: ", result);
                    this.setState({
                        busy: false,
                        errorText: _t("Failed to invite the following users to chat: %(csvUsers)s", {
                            csvUsers: failedUsers.join(", "),
                        }),
                    });
                    return true; // abort
                }
            });
        }

        // the createRoom call will show the room for us, so we don't need to worry about that.
        createRoomPromise.then(abort => {
            if (abort === true) return; // only abort on true booleans, not roomIds or something
            this.props.onFinished();
        }).catch(err => {
            console.error(err);
            this.setState({
                busy: false,
                errorText: _t("We couldn't create your DM. Please check the users you want to invite and try again."),
            });
        });
    };

    _cancel = () => {
        // We do not want the user to close the dialog while an action is in progress
        if (this.state.busy) return;

        this.props.onFinished();
    };

    _updateFilter = (e) => {
        const term = e.target.value;
        this.setState({filterText: term});

        // Debounce server lookups to reduce spam. We don't clear the existing server
        // results because they might still be vaguely accurate, likewise for races which
        // could happen here.
        if (this._debounceTimer) {
            clearTimeout(this._debounceTimer);
        }
        this._debounceTimer = setTimeout(async () => {
            MatrixClientPeg.get().searchUserDirectory({term}).then(r => {
                if (term !== this.state.filterText) {
                    // Discard the results - we were probably too slow on the server-side to make
                    // these results useful. This is a race we want to avoid because we could overwrite
                    // more accurate results.
                    return;
                }
                this.setState({
                    serverResultsMixin: r.results.map(u => ({
                        userId: u.user_id,
                        user: new DirectoryMember(u),
                    })),
                });
            }).catch(e => {
                console.error("Error searching user directory:");
                console.error(e);
                this.setState({serverResultsMixin: []}); // clear results because it's moderately fatal
            });

            // Whenever we search the directory, also try to search the identity server. It's
            // all debounced the same anyways.
            if (!this.state.canUseIdentityServer) {
                // The user doesn't have an identity server set - warn them of that.
                this.setState({tryingIdentityServer: true});
                return;
            }
            if (term.indexOf('@') > 0 && Email.looksValid(term)) {
                // Start off by suggesting the plain email while we try and resolve it
                // to a real account.
                this.setState({
                    // per above: the userId is a lie here - it's just a regular identifier
                    threepidResultsMixin: [{user: new ThreepidMember(term), userId: term}],
                });
                try {
                    const authClient = new IdentityAuthClient();
                    const token = await authClient.getAccessToken();
                    if (term !== this.state.filterText) return; // abandon hope

                    const lookup = await MatrixClientPeg.get().lookupThreePid(
                        'email',
                        term,
                        undefined, // callback
                        token,
                    );
                    if (term !== this.state.filterText) return; // abandon hope

                    if (!lookup || !lookup.mxid) {
                        // We weren't able to find anyone - we're already suggesting the plain email
                        // as an alternative, so do nothing.
                        return;
                    }

                    // We append the user suggestion to give the user an option to click
                    // the email anyways, and so we don't cause things to jump around. In
                    // theory, the user would see the user pop up and think "ah yes, that
                    // person!"
                    const profile = await MatrixClientPeg.get().getProfileInfo(lookup.mxid);
                    if (term !== this.state.filterText || !profile) return; // abandon hope
                    this.setState({
                        threepidResultsMixin: [...this.state.threepidResultsMixin, {
                            user: new DirectoryMember({
                                user_id: lookup.mxid,
                                display_name: profile.displayname,
                                avatar_url: profile.avatar_url,
                            }),
                            userId: lookup.mxid,
                        }],
                    });
                } catch (e) {
                    console.error("Error searching identity server:");
                    console.error(e);
                    this.setState({threepidResultsMixin: []}); // clear results because it's moderately fatal
                }
            }
        }, 150); // 150ms debounce (human reaction time + some)
    };

    _showMoreRecents = () => {
        this.setState({numRecentsShown: this.state.numRecentsShown + INCREMENT_ROOMS_SHOWN});
    };

    _showMoreSuggestions = () => {
        this.setState({numSuggestionsShown: this.state.numSuggestionsShown + INCREMENT_ROOMS_SHOWN});
    };

    _toggleMember = (member: Member) => {
        const targets = this.state.targets.map(t => t); // cheap clone for mutation
        const idx = targets.indexOf(member);
        if (idx >= 0) targets.splice(idx, 1);
        else targets.push(member);
        this.setState({targets});
    };

    _removeMember = (member: Member) => {
        const targets = this.state.targets.map(t => t); // cheap clone for mutation
        const idx = targets.indexOf(member);
        if (idx >= 0) {
            targets.splice(idx, 1);
            this.setState({targets});
        }
    };

    _onPaste = async (e) => {
        // Prevent the text being pasted into the textarea
        e.preventDefault();

        // Process it as a list of addresses to add instead
        const text = e.clipboardData.getData("text");
        const possibleMembers = [
            // If we can avoid hitting the profile endpoint, we should.
            ...this.state.recents,
            ...this.state.suggestions,
            ...this.state.serverResultsMixin,
            ...this.state.threepidResultsMixin,
        ];
        const toAdd = [];
        const failed = [];
        const potentialAddresses = text.split(/[\s,]+/);
        for (const address of potentialAddresses) {
            const member = possibleMembers.find(m => m.userId === address);
            if (member) {
                toAdd.push(member.user);
                continue;
            }

            if (address.indexOf('@') > 0 && Email.looksValid(address)) {
                toAdd.push(new ThreepidMember(address));
                continue;
            }

            if (address[0] !== '@') {
                failed.push(address); // not a user ID
                continue;
            }

            try {
                const profile = await MatrixClientPeg.get().getProfileInfo(address);
                const displayName = profile ? profile.displayname : null;
                const avatarUrl = profile ? profile.avatar_url : null;
                toAdd.push(new DirectoryMember({
                    user_id: address,
                    display_name: displayName,
                    avatar_url: avatarUrl,
                }));
            } catch (e) {
                console.error("Error looking up profile for " + address);
                console.error(e);
                failed.push(address);
            }
        }

        if (failed.length > 0) {
            const QuestionDialog = sdk.getComponent('dialogs.QuestionDialog');
            Modal.createTrackedDialog('Invite Paste Fail', '', QuestionDialog, {
                title: _t('Failed to find the following users'),
                description: _t(
                    "The following users might not exist or are invalid, and cannot be invited: %(csvNames)s",
                    {csvNames: failed.join(", ")},
                ),
                button: _t('OK'),
            });
        }

        this.setState({targets: [...this.state.targets, ...toAdd]});
    };

    _onClickInputArea = (e) => {
        // Stop the browser from highlighting text
        e.preventDefault();
        e.stopPropagation();

        if (this._editorRef && this._editorRef.current) {
            this._editorRef.current.focus();
        }
    };

    _onUseDefaultIdentityServerClick = (e) => {
        e.preventDefault();

        // Update the IS in account data. Actually using it may trigger terms.
        // eslint-disable-next-line react-hooks/rules-of-hooks
        useDefaultIdentityServer();
        this.setState({canUseIdentityServer: true, tryingIdentityServer: false});
    };

    _onManageSettingsClick = (e) => {
        e.preventDefault();
        dis.dispatch({ action: 'view_user_settings' });
        this._cancel();
    };

    _renderSection(kind: "recents"|"suggestions") {
        let sourceMembers = kind === 'recents' ? this.state.recents : this.state.suggestions;
        let showNum = kind === 'recents' ? this.state.numRecentsShown : this.state.numSuggestionsShown;
        const showMoreFn = kind === 'recents' ? this._showMoreRecents.bind(this) : this._showMoreSuggestions.bind(this);
        const lastActive = (m) => kind === 'recents' ? m.lastActive : null;
        const sectionName = kind === 'recents' ? _t("Recent Conversations") : _t("Suggestions");

        // Mix in the server results if we have any, but only if we're searching. We track the additional
        // members separately because we want to filter sourceMembers but trust the mixin arrays to have
        // the right members in them.
        let additionalMembers = [];
        const hasMixins = this.state.serverResultsMixin || this.state.threepidResultsMixin;
        if (this.state.filterText && hasMixins && kind === 'suggestions') {
            // We don't want to duplicate members though, so just exclude anyone we've already seen.
            const notAlreadyExists = (u: Member): boolean => {
                return !sourceMembers.some(m => m.userId === u.userId)
                    && !additionalMembers.some(m => m.userId === u.userId);
            };

            const uniqueServerResults = this.state.serverResultsMixin.filter(notAlreadyExists);
            additionalMembers = additionalMembers.concat(...uniqueServerResults);

            const uniqueThreepidResults = this.state.threepidResultsMixin.filter(notAlreadyExists);
            additionalMembers = additionalMembers.concat(...uniqueThreepidResults);
        }

        // Hide the section if there's nothing to filter by
        if (sourceMembers.length === 0 && additionalMembers.length === 0) return null;

        // Do some simple filtering on the input before going much further. If we get no results, say so.
        if (this.state.filterText) {
            const filterBy = this.state.filterText.toLowerCase();
            sourceMembers = sourceMembers
                .filter(m => m.user.name.toLowerCase().includes(filterBy) || m.userId.toLowerCase().includes(filterBy));

            if (sourceMembers.length === 0 && additionalMembers.length === 0) {
                return (
                    <div className='mx_DMInviteDialog_section'>
                        <h3>{sectionName}</h3>
                        <p>{_t("No results")}</p>
                    </div>
                );
            }
        }

        // Now we mix in the additional members. Again, we presume these have already been filtered. We
        // also assume they are more relevant than our suggestions and prepend them to the list.
        sourceMembers = [...additionalMembers, ...sourceMembers];

        // If we're going to hide one member behind 'show more', just use up the space of the button
        // with the member's tile instead.
        if (showNum === sourceMembers.length - 1) showNum++;

        // .slice() will return an incomplete array but won't error on us if we go too far
        const toRender = sourceMembers.slice(0, showNum);
        const hasMore = toRender.length < sourceMembers.length;

        const AccessibleButton = sdk.getComponent("elements.AccessibleButton");
        let showMore = null;
        if (hasMore) {
            showMore = (
                <AccessibleButton onClick={showMoreFn} kind="link">
                    {_t("Show more")}
                </AccessibleButton>
            );
        }

        const tiles = toRender.map(r => (
            <DMRoomTile
                member={r.user}
                lastActiveTs={lastActive(r)}
                key={r.userId}
                onToggle={this._toggleMember}
                highlightWord={this.state.filterText}
                isSelected={this.state.targets.some(t => t.userId === r.userId)}
            />
        ));
        return (
            <div className='mx_DMInviteDialog_section'>
                <h3>{sectionName}</h3>
                {tiles}
                {showMore}
            </div>
        );
    }

    _renderEditor() {
        const targets = this.state.targets.map(t => (
            <DMUserTile member={t} onRemove={this._removeMember} key={t.userId} />
        ));
        const input = (
            <textarea
                key={"input"}
                rows={1}
                onChange={this._updateFilter}
                defaultValue={this.state.filterText}
                ref={this._editorRef}
                onPaste={this._onPaste}
            />
        );
        return (
            <div className='mx_DMInviteDialog_editor' onClick={this._onClickInputArea}>
                {targets}
                {input}
            </div>
        );
    }

    _renderIdentityServerWarning() {
        if (!this.state.tryingIdentityServer || this.state.canUseIdentityServer) {
            return null;
        }

        const defaultIdentityServerUrl = getDefaultIdentityServerUrl();
        if (defaultIdentityServerUrl) {
            return (
                <div className="mx_AddressPickerDialog_identityServer">{_t(
                    "Use an identity server to invite by email. " +
                    "<default>Use the default (%(defaultIdentityServerName)s)</default> " +
                    "or manage in <settings>Settings</settings>.",
                    {
                        defaultIdentityServerName: abbreviateUrl(defaultIdentityServerUrl),
                    },
                    {
                        default: sub => <a href="#" onClick={this._onUseDefaultIdentityServerClick}>{sub}</a>,
                        settings: sub => <a href="#" onClick={this._onManageSettingsClick}>{sub}</a>,
                    },
                )}</div>
            );
        } else {
            return (
                <div className="mx_AddressPickerDialog_identityServer">{_t(
                    "Use an identity server to invite by email. " +
                    "Manage in <settings>Settings</settings>.",
                    {}, {
                        settings: sub => <a href="#" onClick={this._onManageSettingsClick}>{sub}</a>,
                    },
                )}</div>
            );
        }
    }

    render() {
        const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
        const AccessibleButton = sdk.getComponent("elements.AccessibleButton");
        const Spinner = sdk.getComponent("elements.Spinner");

        let spinner = null;
        if (this.state.busy) {
            spinner = <Spinner w={20} h={20} />;
        }

        const userId = MatrixClientPeg.get().getUserId();
        return (
            <BaseDialog
                className='mx_DMInviteDialog'
                hasCancel={true}
                onFinished={this._cancel}
                title={_t("Direct Messages")}
            >
                <div className='mx_DMInviteDialog_content'>
                    <p>
                        {_t(
                            "If you can't find someone, ask them for their username, or share your " +
                            "username (%(userId)s) or <a>profile link</a>.",
                            {userId},
                            {a: (sub) => <a href={makeUserPermalink(userId)} rel="noopener" target="_blank">{sub}</a>},
                        )}
                    </p>
                    <div className='mx_DMInviteDialog_addressBar'>
                        {this._renderEditor()}
                        <div className='mx_DMInviteDialog_buttonAndSpinner'>
                            <AccessibleButton
                                kind="primary"
                                onClick={this._startDm}
                                className='mx_DMInviteDialog_goButton'
                                disabled={this.state.busy}
                            >
                                {_t("Go")}
                            </AccessibleButton>
                            {spinner}
                        </div>
                    </div>
                    {this._renderIdentityServerWarning()}
                    <div className='error'>{this.state.errorText}</div>
                    {this._renderSection('recents')}
                    {this._renderSection('suggestions')}
                </div>
            </BaseDialog>
        );
    }
}