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/MatrixSchemePermalinkConstructor.ts

@@ -0,0 +1,105 @@
+/*
+Copyright 2022 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";
+
+/**
+ * Generates matrix: scheme permalinks
+ */
+export default class MatrixSchemePermalinkConstructor extends PermalinkConstructor {
+    constructor() {
+        super();
+    }
+
+    private encodeEntity(entity: string): string {
+        if (entity[0] === "!") {
+            return `roomid/${entity.slice(1)}`;
+        } else if (entity[0] === "#") {
+            return `r/${entity.slice(1)}`;
+        } else if (entity[0] === "@") {
+            return `u/${entity.slice(1)}`;
+        } else if (entity[0] === "$") {
+            return `e/${entity.slice(1)}`;
+        }
+
+        throw new Error("Cannot encode entity: " + entity);
+    }
+
+    forEvent(roomId: string, eventId: string, serverCandidates: string[]): string {
+        return `matrix:${this.encodeEntity(roomId)}` +
+            `/${this.encodeEntity(eventId)}${this.encodeServerCandidates(serverCandidates)}`;
+    }
+
+    forRoom(roomIdOrAlias: string, serverCandidates: string[]): string {
+        return `matrix:${this.encodeEntity(roomIdOrAlias)}${this.encodeServerCandidates(serverCandidates)}`;
+    }
+
+    forUser(userId: string): string {
+        return `matrix:${this.encodeEntity(userId)}`;
+    }
+
+    forGroup(groupId: string): string {
+        throw new Error("Deliberately not implemented");
+    }
+
+    forEntity(entityId: string): string {
+        return `matrix:${this.encodeEntity(entityId)}`;
+    }
+
+    isPermalinkHost(testHost: string): boolean {
+        // TODO: Change API signature to accept the URL for checking
+        return testHost === "";
+    }
+
+    encodeServerCandidates(candidates: string[]) {
+        if (!candidates || candidates.length === 0) return '';
+        return `?via=${candidates.map(c => encodeURIComponent(c)).join("&via=")}`;
+    }
+
+    parsePermalink(fullUrl: string): PermalinkParts {
+        if (!fullUrl || !fullUrl.startsWith("matrix:")) {
+            throw new Error("Does not appear to be a permalink");
+        }
+
+        const parts = fullUrl.substring("matrix:".length).split('/');
+
+        const identifier = parts[0];
+        const entityNoSigil = parts[1];
+        if (identifier === 'u') {
+            // Probably a user, no further parsing needed.
+            return PermalinkParts.forUser(`@${entityNoSigil}`);
+        } else if (identifier === 'r' || identifier === 'roomid') {
+            const sigil = identifier === 'r' ? '#' : '!';
+
+            if (parts.length === 2) { // room without event permalink
+                const [roomId, query = ""] = entityNoSigil.split("?");
+                const via = query.split(/&?via=/g).filter(p => !!p);
+                return PermalinkParts.forRoom(`${sigil}${roomId}`, via);
+            }
+
+            if (parts[2] === 'e') { // event permalink
+                const eventIdAndQuery = parts.length > 3 ? parts.slice(3).join('/') : "";
+                const [eventId, query = ""] = eventIdAndQuery.split("?");
+                const via = query.split(/&?via=/g).filter(p => !!p);
+                return PermalinkParts.forEvent(`${sigil}${entityNoSigil}`, `$${eventId}`, via);
+            }
+
+            throw new Error("Faulty room permalink");
+        } else {
+            throw new Error("Unknown entity type in permalink");
+        }
+    }
+}