ThreadNet-Web/src/components/views/messages/RoomCreate.tsx

/*
Copyright 2018 New Vector Ltd
Copyright 2019, 2023 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, { useCallback, useContext } from "react";
import { logger } from "matrix-js-sdk/src/logger";
import { MatrixEvent } from "matrix-js-sdk/src/models/event";

import dis from "../../../dispatcher/dispatcher";
import { Action } from "../../../dispatcher/actions";
import { RoomPermalinkCreator } from "../../../utils/permalinks/Permalinks";
import { _t } from "../../../languageHandler";
import { MatrixClientPeg } from "../../../MatrixClientPeg";
import EventTileBubble from "./EventTileBubble";
import { ViewRoomPayload } from "../../../dispatcher/payloads/ViewRoomPayload";
import RoomContext from "../../../contexts/RoomContext";
import { useRoomState } from "../../../hooks/useRoomState";

interface IProps {
    /** The m.room.create MatrixEvent that this tile represents */
    mxEvent: MatrixEvent;
    timestamp?: JSX.Element;
}

/**
 * A message tile showing that this room was created as an upgrade of a previous
 * room.
 */
export const RoomCreate: React.FC<IProps> = ({ mxEvent, timestamp }) => {
    // Note: we ask the room for its predecessor here, instead of directly using
    // the information inside mxEvent. This allows us the flexibility later to
    // use a different predecessor (e.g. through MSC3946) and still display it
    // in the timeline location of the create event.
    const roomContext = useContext(RoomContext);
    const predecessor = useRoomState(
        roomContext.room,
        useCallback((state) => state.findPredecessor(), []),
    );

    const onLinkClicked = useCallback(
        (e: React.MouseEvent): void => {
            e.preventDefault();

            dis.dispatch<ViewRoomPayload>({
                action: Action.ViewRoom,
                event_id: predecessor.eventId,
                highlighted: true,
                room_id: predecessor.roomId,
                metricsTrigger: "Predecessor",
                metricsViaKeyboard: e.type !== "click",
            });
        },
        [predecessor?.eventId, predecessor?.roomId],
    );

    if (!roomContext.room || roomContext.room.roomId !== mxEvent.getRoomId()) {
        logger.warn(
            "RoomCreate unexpectedly used outside of the context of the room containing this m.room.create event.",
        );
        return <></>;
    }

    if (!predecessor) {
        logger.warn("RoomCreate unexpectedly used in a room with no predecessor.");
        return <div />;
    }

    const prevRoom = MatrixClientPeg.get().getRoom(predecessor.roomId);
    if (!prevRoom) {
        logger.warn(`Failed to find predecessor room with id ${predecessor.roomId}`);
        return <></>;
    }
    const permalinkCreator = new RoomPermalinkCreator(prevRoom, predecessor.roomId);
    permalinkCreator.load();
    let predecessorPermalink: string;
    if (predecessor.eventId) {
        predecessorPermalink = permalinkCreator.forEvent(predecessor.eventId);
    } else {
        predecessorPermalink = permalinkCreator.forRoom();
    }
    const link = (
        <a href={predecessorPermalink} onClick={onLinkClicked}>
            {_t("Click here to see older messages.")}
        </a>
    );

    return (
        <EventTileBubble
            className="mx_CreateEvent"
            title={_t("This room is a continuation of another conversation.")}
            subtitle={link}
            timestamp={timestamp}
        />
    );
};