element-web/src/linkify-matrix.ts

/*
Copyright 2015, 2016 OpenMarket Ltd
Copyright 2019 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 * as linkifyjs from "linkifyjs";
import { Opts, registerCustomProtocol, registerPlugin } from "linkifyjs";
import linkifyElement from "linkify-element";
import linkifyString from "linkify-string";
import { User } from "matrix-js-sdk/src/matrix";

import {
    parsePermalink,
    tryTransformEntityToPermalink,
    tryTransformPermalinkToLocalHref,
} from "./utils/permalinks/Permalinks";
import dis from "./dispatcher/dispatcher";
import { Action } from "./dispatcher/actions";
import { ViewUserPayload } from "./dispatcher/payloads/ViewUserPayload";
import { ViewRoomPayload } from "./dispatcher/payloads/ViewRoomPayload";

export enum Type {
    URL = "url",
    UserId = "userid",
    RoomAlias = "roomalias",
}

// Linkify stuff doesn't type scanner/parser/utils properly :/
function matrixOpaqueIdLinkifyParser({
    scanner,
    parser,
    utils,
    token,
    name,
}: {
    scanner: any;
    parser: any;
    utils: any;
    token: "#" | "+" | "@";
    name: Type;
}): void {
    const {
        DOT,
        // IPV4 necessity
        NUM,
        TLD,
        COLON,
        SYM,
        HYPHEN,
        UNDERSCORE,
        // because 'localhost' is tokenised to the localhost token,
        // usernames @localhost:foo.com are otherwise not matched!
        LOCALHOST,
        domain,
    } = scanner.tokens;

    const S_START = parser.start;
    const matrixSymbol = utils.createTokenClass(name, { isLink: true });

    const localpartTokens = [domain, TLD, LOCALHOST, SYM, UNDERSCORE, HYPHEN];
    const domainpartTokens = [domain, TLD, LOCALHOST, HYPHEN];

    const INITIAL_STATE = S_START.tt(token);

    const LOCALPART_STATE = INITIAL_STATE.tt(domain);
    for (const token of localpartTokens) {
        INITIAL_STATE.tt(token, LOCALPART_STATE);
        LOCALPART_STATE.tt(token, LOCALPART_STATE);
    }
    const LOCALPART_STATE_DOT = LOCALPART_STATE.tt(DOT);
    for (const token of localpartTokens) {
        LOCALPART_STATE_DOT.tt(token, LOCALPART_STATE);
    }

    const DOMAINPART_STATE_DOT = LOCALPART_STATE.tt(COLON);
    const DOMAINPART_STATE = DOMAINPART_STATE_DOT.tt(domain);
    DOMAINPART_STATE.tt(DOT, DOMAINPART_STATE_DOT);
    for (const token of domainpartTokens) {
        DOMAINPART_STATE.tt(token, DOMAINPART_STATE);
        // we are done if we have a domain
        DOMAINPART_STATE.tt(token, matrixSymbol);
    }

    // accept repeated TLDs (e.g .org.uk) but do not accept double dots: ..
    for (const token of domainpartTokens) {
        DOMAINPART_STATE_DOT.tt(token, DOMAINPART_STATE);
    }

    const PORT_STATE = DOMAINPART_STATE.tt(COLON);

    PORT_STATE.tt(NUM, matrixSymbol);
}

function onUserClick(event: MouseEvent, userId: string): void {
    event.preventDefault();
    dis.dispatch<ViewUserPayload>({
        action: Action.ViewUser,
        member: new User(userId),
    });
}

function onAliasClick(event: MouseEvent, roomAlias: string): void {
    event.preventDefault();
    dis.dispatch<ViewRoomPayload>({
        action: Action.ViewRoom,
        room_alias: roomAlias,
        metricsTrigger: "Timeline",
        metricsViaKeyboard: false,
    });
}

const escapeRegExp = function (s: string): string {
    return s.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
};

// Recognise URLs from both our local and official Element deployments.
// Anyone else really should be using matrix.to. vector:// allowed to support Element Desktop relative links.
export const ELEMENT_URL_PATTERN =
    "^(?:vector://|https?://)?(?:" +
    escapeRegExp(window.location.host + window.location.pathname) +
    "|" +
    "(?:www\\.)?(?:riot|vector)\\.im/(?:app|beta|staging|develop)/|" +
    "(?:app|beta|staging|develop)\\.element\\.io/" +
    ")(#.*)";

export const options: Opts = {
    events: function (href: string, type: string): Partial<GlobalEventHandlers> {
        switch (type as Type) {
            case Type.URL: {
                // intercept local permalinks to users and show them like userids (in userinfo of current room)
                try {
                    const permalink = parsePermalink(href);
                    if (permalink?.userId) {
                        return {
                            // @ts-ignore see https://linkify.js.org/docs/options.html
                            click: function (e: MouseEvent) {
                                onUserClick(e, permalink.userId);
                            },
                        };
                    } else {
                        // for events, rooms etc. (anything other than users)
                        const localHref = tryTransformPermalinkToLocalHref(href);
                        if (localHref !== href) {
                            // it could be converted to a localHref -> therefore handle locally
                            return {
                                // @ts-ignore see https://linkify.js.org/docs/options.html
                                click: function (e: MouseEvent) {
                                    e.preventDefault();
                                    window.location.hash = localHref;
                                },
                            };
                        }
                    }
                } catch (e) {
                    // OK fine, it's not actually a permalink
                }
                break;
            }
            case Type.UserId:
                return {
                    // @ts-ignore see https://linkify.js.org/docs/options.html
                    click: function (e: MouseEvent) {
                        const userId = parsePermalink(href).userId;
                        onUserClick(e, userId);
                    },
                };
            case Type.RoomAlias:
                return {
                    // @ts-ignore see https://linkify.js.org/docs/options.html
                    click: function (e: MouseEvent) {
                        const alias = parsePermalink(href).roomIdOrAlias;
                        onAliasClick(e, alias);
                    },
                };
        }
    },

    formatHref: function (href: string, type: Type | string): string {
        switch (type) {
            case Type.RoomAlias:
            case Type.UserId:
            default: {
                return tryTransformEntityToPermalink(href);
            }
        }
    },

    attributes: {
        rel: "noreferrer noopener",
    },

    ignoreTags: ["pre", "code"],

    className: "linkified",

    target: function (href: string, type: Type | string): string {
        if (type === Type.URL) {
            try {
                const transformed = tryTransformPermalinkToLocalHref(href);
                if (
                    transformed !== href || // if it could be converted to handle locally for matrix symbols e.g. @user:server.tdl and matrix.to
                    decodeURIComponent(href).match(ELEMENT_URL_PATTERN) // for https links to Element domains
                ) {
                    return null;
                } else {
                    return "_blank";
                }
            } catch (e) {
                // malformed URI
            }
        }
        return null;
    },
};

// Run the plugins
registerPlugin(Type.RoomAlias, ({ scanner, parser, utils }: any) => {
    const token = scanner.tokens.POUND as "#";
    matrixOpaqueIdLinkifyParser({
        scanner,
        parser,
        utils,
        token,
        name: Type.RoomAlias,
    });
});

registerPlugin(Type.UserId, ({ scanner, parser, utils }: any) => {
    const token = scanner.tokens.AT as "@";
    matrixOpaqueIdLinkifyParser({
        scanner,
        parser,
        utils,
        token,
        name: Type.UserId,
    });
});

registerCustomProtocol("matrix", true);

export const linkify = linkifyjs;
export const _linkifyElement = linkifyElement;
export const _linkifyString = linkifyString;