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 { EventListeners, Opts, registerCustomProtocol, registerPlugin } from "linkifyjs";
import linkifyElement from "linkify-element";
import linkifyString from "linkify-string";
import { getHttpUriForMxc, 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";
import { MatrixClientPeg } from "./MatrixClientPeg";
import { PERMITTED_URL_SCHEMES } from "./utils/UrlUtils";

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

function matrixOpaqueIdLinkifyParser({
    scanner,
    parser,
    token,
    name,
}: {
    scanner: linkifyjs.ScannerInit;
    parser: linkifyjs.ParserInit;
    token: "#" | "+" | "@";
    name: Type;
}): void {
    const {
        DOT,
        // IPV4 necessity
        NUM,
        COLON,
        SYM,
        SLASH,
        EQUALS,
        HYPHEN,
        UNDERSCORE,
    } = scanner.tokens;

    // Contains NUM, WORD, UWORD, EMOJI, TLD, UTLD, SCHEME, SLASH_SCHEME and LOCALHOST plus custom protocols (e.g. "matrix")
    const { domain } = scanner.tokens.groups;

    // Tokens we need that are not contained in the domain group
    const additionalLocalpartTokens = [DOT, SYM, SLASH, EQUALS, UNDERSCORE, HYPHEN];
    const additionalDomainpartTokens = [HYPHEN];

    const matrixToken = linkifyjs.createTokenClass(name, { isLink: true });
    const matrixTokenState = new linkifyjs.State(matrixToken) as any as linkifyjs.State<linkifyjs.MultiToken>; // linkify doesn't appear to type this correctly

    const matrixTokenWithPort = linkifyjs.createTokenClass(name, { isLink: true });
    const matrixTokenWithPortState = new linkifyjs.State(
        matrixTokenWithPort,
    ) as any as linkifyjs.State<linkifyjs.MultiToken>; // linkify doesn't appear to type this correctly

    const INITIAL_STATE = parser.start.tt(token);

    // Localpart
    const LOCALPART_STATE = new linkifyjs.State<linkifyjs.MultiToken>();
    INITIAL_STATE.ta(domain, LOCALPART_STATE);
    INITIAL_STATE.ta(additionalLocalpartTokens, LOCALPART_STATE);
    LOCALPART_STATE.ta(domain, LOCALPART_STATE);
    LOCALPART_STATE.ta(additionalLocalpartTokens, LOCALPART_STATE);

    // Domainpart
    const DOMAINPART_STATE_DOT = LOCALPART_STATE.tt(COLON);
    DOMAINPART_STATE_DOT.ta(domain, matrixTokenState);
    DOMAINPART_STATE_DOT.ta(additionalDomainpartTokens, matrixTokenState);
    matrixTokenState.ta(domain, matrixTokenState);
    matrixTokenState.ta(additionalDomainpartTokens, matrixTokenState);
    matrixTokenState.tt(DOT, DOMAINPART_STATE_DOT);

    // Port suffixes
    matrixTokenState.tt(COLON).tt(NUM, matrixTokenWithPortState);
}

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): EventListeners {
        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 {
                            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 {
                                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 {
                    click: function (e: MouseEvent) {
                        const userId = parsePermalink(href)?.userId ?? href;
                        if (userId) onUserClick(e, userId);
                    },
                };
            case Type.RoomAlias:
                return {
                    click: function (e: MouseEvent) {
                        const alias = parsePermalink(href)?.roomIdOrAlias ?? href;
                        if (alias) onAliasClick(e, alias);
                    },
                };
        }

        return {};
    },

    formatHref: function (href: string, type: Type | string): string {
        switch (type) {
            case "url":
                if (href.startsWith("mxc://") && MatrixClientPeg.get()) {
                    return getHttpUriForMxc(
                        MatrixClientPeg.get()!.baseUrl,
                        href,
                        undefined,
                        undefined,
                        undefined,
                        false,
                        true,
                    );
                }
            // fallthrough
            case Type.RoomAlias:
            case Type.UserId:
            default: {
                return tryTransformEntityToPermalink(MatrixClientPeg.safeGet(), 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 "";
                } else {
                    return "_blank";
                }
            } catch (e) {
                // malformed URI
            }
        }
        return "";
    },
};

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

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

// Linkify supports some common protocols but not others, register all permitted url schemes if unsupported
// https://github.com/Hypercontext/linkifyjs/blob/f4fad9df1870259622992bbfba38bfe3d0515609/packages/linkifyjs/src/scanner.js#L133-L141
// This also handles registering the `matrix:` protocol scheme
const linkifySupportedProtocols = ["file", "mailto", "http", "https", "ftp", "ftps"];
const optionalSlashProtocols = [
    "bitcoin",
    "geo",
    "im",
    "magnet",
    "mailto",
    "matrix",
    "news",
    "openpgp4fpr",
    "sip",
    "sms",
    "smsto",
    "tel",
    "urn",
    "xmpp",
];

PERMITTED_URL_SCHEMES.forEach((scheme) => {
    if (!linkifySupportedProtocols.includes(scheme)) {
        registerCustomProtocol(scheme, optionalSlashProtocols.includes(scheme));
    }
});

registerCustomProtocol("mxc", false);

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