Parse matrix-schemed URIs (#7453)

Co-authored-by: J. Ryan Stinnett <jryans@gmail.com>
Co-authored-by: Dariusz Niemczyk <dariuszn@element.io>
Co-authored-by: Timo K <toger5@hotmail.de>

With this pr all href use matrix matrix.to links. As a consequence right-click copy link will always return get you a sharable matrix.to link.

src/utils/permalinks/MatrixToPermalinkConstructor.ts

@@ -0,0 +1,92 @@
+/*
+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 PermalinkConstructor, { PermalinkParts } from "./PermalinkConstructor";
+
+export const host = "matrix.to";
+export const baseUrl = `https://${host}`;
+
+/**
+ * Generates matrix.to permalinks
+ */
+export default class MatrixToPermalinkConstructor extends PermalinkConstructor {
+    constructor() {
+        super();
+    }
+
+    forEvent(roomId: string, eventId: string, serverCandidates: string[]): string {
+        return `${baseUrl}/#/${roomId}/${eventId}${this.encodeServerCandidates(serverCandidates)}`;
+    }
+
+    forRoom(roomIdOrAlias: string, serverCandidates: string[]): string {
+        return `${baseUrl}/#/${roomIdOrAlias}${this.encodeServerCandidates(serverCandidates)}`;
+    }
+
+    forUser(userId: string): string {
+        return `${baseUrl}/#/${userId}`;
+    }
+
+    forGroup(groupId: string): string {
+        return `${baseUrl}/#/${groupId}`;
+    }
+
+    forEntity(entityId: string): string {
+        return `${baseUrl}/#/${entityId}`;
+    }
+
+    isPermalinkHost(testHost: string): boolean {
+        return testHost === host;
+    }
+
+    encodeServerCandidates(candidates: string[]) {
+        if (!candidates || candidates.length === 0) return '';
+        return `?via=${candidates.map(c => encodeURIComponent(c)).join("&via=")}`;
+    }
+
+    // Heavily inspired by/borrowed from the matrix-bot-sdk (with permission):
+    // https://github.com/turt2live/matrix-js-bot-sdk/blob/7c4665c9a25c2c8e0fe4e509f2616505b5b66a1c/src/Permalinks.ts#L33-L61
+    parsePermalink(fullUrl: string): PermalinkParts {
+        if (!fullUrl || !fullUrl.startsWith(baseUrl)) {
+            throw new Error("Does not appear to be a permalink");
+        }
+
+        const parts = fullUrl.substring(`${baseUrl}/#/`.length).split("/");
+
+        const entity = parts[0];
+        if (entity[0] === '@') {
+            // Probably a user, no further parsing needed.
+            return PermalinkParts.forUser(entity);
+        } else if (entity[0] === '+') {
+            // Probably a group, no further parsing needed.
+            return PermalinkParts.forGroup(entity);
+        } else if (entity[0] === '#' || entity[0] === '!') {
+            if (parts.length === 1) { // room without event permalink
+                const [roomId, query=""] = entity.split("?");
+                const via = query.split(/&?via=/g).filter(p => !!p);
+                return PermalinkParts.forRoom(roomId, via);
+            }
+
+            // rejoin the rest because v3 events can have slashes (annoyingly)
+            const eventIdAndQuery = parts.length > 1 ? parts.slice(1).join('/') : "";
+            const [eventId, query=""] = eventIdAndQuery.split("?");
+            const via = query.split(/&?via=/g).filter(p => !!p);
+
+            return PermalinkParts.forEvent(entity, eventId, via);
+        } else {
+            throw new Error("Unknown entity type in permalink");
+        }
+    }
+}