From b7ba9b3c413043ac759aacb15fe6650f2be2a73b Mon Sep 17 00:00:00 2001
From: Travis Ralston <travpc@gmail.com>
Date: Thu, 14 May 2020 14:16:26 -0600
Subject: [PATCH] Replace ChaoticAlgorithm with NaturalAlgorithm for list
 behaviour

---
 .../list_ordering/ChaoticAlgorithm.ts         | 38 -------------
 .../list_ordering/NaturalAlgorithm.ts         | 56 +++++++++++++++++++
 .../algorithms/list_ordering/index.ts         |  4 +-
 3 files changed, 58 insertions(+), 40 deletions(-)
 delete mode 100644 src/stores/room-list/algorithms/list_ordering/ChaoticAlgorithm.ts
 create mode 100644 src/stores/room-list/algorithms/list_ordering/NaturalAlgorithm.ts

diff --git a/src/stores/room-list/algorithms/list_ordering/ChaoticAlgorithm.ts b/src/stores/room-list/algorithms/list_ordering/ChaoticAlgorithm.ts
deleted file mode 100644
index 185fb606fb..0000000000
--- a/src/stores/room-list/algorithms/list_ordering/ChaoticAlgorithm.ts
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
-Copyright 2020 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 { Algorithm } from "./Algorithm";
-import { ITagMap } from "../models";
-
-/**
- * A demonstration/temporary algorithm to verify the API surface works.
- * TODO: Remove this before shipping
- */
-export class ChaoticAlgorithm extends Algorithm {
-
-    constructor() {
-        super();
-        console.log("Constructed a ChaoticAlgorithm");
-    }
-
-    protected async generateFreshTags(updatedTagMap: ITagMap): Promise<any> {
-        return Promise.resolve();
-    }
-
-    public async handleRoomUpdate(room, cause): Promise<boolean> {
-        return Promise.resolve(false);
-    }
-}
diff --git a/src/stores/room-list/algorithms/list_ordering/NaturalAlgorithm.ts b/src/stores/room-list/algorithms/list_ordering/NaturalAlgorithm.ts
new file mode 100644
index 0000000000..1265564352
--- /dev/null
+++ b/src/stores/room-list/algorithms/list_ordering/NaturalAlgorithm.ts
@@ -0,0 +1,56 @@
+/*
+Copyright 2020 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 { Algorithm } from "./Algorithm";
+import { ITagMap } from "../models";
+import { sortRoomsWithAlgorithm } from "../tag_sorting";
+
+/**
+ * Uses the natural tag sorting algorithm order to determine tag ordering. No
+ * additional behavioural changes are present.
+ */
+export class NaturalAlgorithm extends Algorithm {
+
+    constructor() {
+        super();
+        console.log("Constructed a NaturalAlgorithm");
+    }
+
+    protected async generateFreshTags(updatedTagMap: ITagMap): Promise<any> {
+        for (const tagId of Object.keys(updatedTagMap)) {
+            const unorderedRooms = updatedTagMap[tagId];
+
+            const sortBy = this.sortAlgorithms[tagId];
+            if (!sortBy) throw new Error(`${tagId} does not have a sorting algorithm`);
+
+            updatedTagMap[tagId] = await sortRoomsWithAlgorithm(unorderedRooms, tagId, sortBy);
+        }
+    }
+
+    public async handleRoomUpdate(room, cause): Promise<boolean> {
+        const tags = this.roomIdsToTags[room.roomId];
+        if (!tags) {
+            console.warn(`No tags known for "${room.name}" (${room.roomId})`);
+            return false;
+        }
+        for (const tag of tags) {
+            // TODO: Optimize this loop to avoid useless operations
+            // For example, we can skip updates to alphabetic (sometimes) and manually ordered tags
+            this.cached[tag] = await sortRoomsWithAlgorithm(this.cached[tag], tag, this.sortAlgorithms[tag]);
+        }
+        return true; // assume we changed something
+    }
+}
diff --git a/src/stores/room-list/algorithms/list_ordering/index.ts b/src/stores/room-list/algorithms/list_ordering/index.ts
index 35f4af14cf..bcccd150cd 100644
--- a/src/stores/room-list/algorithms/list_ordering/index.ts
+++ b/src/stores/room-list/algorithms/list_ordering/index.ts
@@ -15,12 +15,12 @@ limitations under the License.
 */
 
 import { Algorithm } from "./Algorithm";
-import { ChaoticAlgorithm } from "./ChaoticAlgorithm";
 import { ImportanceAlgorithm } from "./ImportanceAlgorithm";
 import { ListAlgorithm } from "../models";
+import { NaturalAlgorithm } from "./NaturalAlgorithm";
 
 const ALGORITHM_FACTORIES: { [algorithm in ListAlgorithm]: () => Algorithm } = {
-    [ListAlgorithm.Natural]: () => new ChaoticAlgorithm(),
+    [ListAlgorithm.Natural]: () => new NaturalAlgorithm(),
     [ListAlgorithm.Importance]: () => new ImportanceAlgorithm(),
 };