From f1c18e0b09646e7095daf3f8f5391ab7a69adb98 Mon Sep 17 00:00:00 2001
From: PrivateGER <privateger@privateger.me>
Date: Sat, 15 Jul 2023 02:10:42 +0200
Subject: [PATCH] Allow relevancy sorting of Meilisearch

---
 .../src/server/api/endpoints/notes/search.ts  | 80 ++++++++++++++-----
 1 file changed, 61 insertions(+), 19 deletions(-)

diff --git a/packages/backend/src/server/api/endpoints/notes/search.ts b/packages/backend/src/server/api/endpoints/notes/search.ts
index b4d83aa0bc..c0e1c0345c 100644
--- a/packages/backend/src/server/api/endpoints/notes/search.ts
+++ b/packages/backend/src/server/api/endpoints/notes/search.ts
@@ -1,4 +1,4 @@
-import { In } from "typeorm";
+import {FindManyOptions, In} from "typeorm";
 import { Notes } from "@/models/index.js";
 import { Note } from "@/models/entities/note.js";
 import config from "@/config/index.js";
@@ -58,6 +58,11 @@ export const paramDef = {
 			nullable: true,
 			default: null,
 		},
+		order: {
+			type: "string",
+			default: "chronological",
+			nullable: true,
+		},
 	},
 	required: ["query"],
 } as const;
@@ -156,9 +161,6 @@ export default define(meta, paramDef, async (ps, me) => {
 				where: {
 					id: In(chunk),
 				},
-				order: {
-					id: "DESC",
-				},
 			});
 
 			// The notes are checked for visibility and muted/blocked users when packed
@@ -175,19 +177,32 @@ export default define(meta, paramDef, async (ps, me) => {
 	} else if (meilisearch) {
 		let start = 0;
 		const chunkSize = 100;
+		const sortByDate = ps.order !== "relevancy";
+
+		type NoteResult = {
+			id: string,
+			createdAt: number
+		}
+		const extractedNotes: NoteResult[] = [];
 
-		// Use meilisearch to fetch and step through all search results that could match the requirements
-		const ids = [];
 		while (true) {
-			const results = await meilisearch.search(ps.query, chunkSize, start, me);
+			const searchRes = await meilisearch.search(
+				ps.query,
+				chunkSize,
+				start,
+				me,
+			);
+			const results: MeilisearchNote[] = searchRes.hits as MeilisearchNote[];
+
+			console.log(JSON.stringify(results));
 
 			start += chunkSize;
 
-			if (results.hits.length === 0) {
+			if (results.length === 0) {
 				break;
 			}
 
-			const res = results.hits
+			const res = results
 				.filter((key: MeilisearchNote) => {
 					if (ps.userId && key.userId !== ps.userId) {
 						return false;
@@ -203,34 +218,61 @@ export default define(meta, paramDef, async (ps, me) => {
 					}
 					return true;
 				})
-				.map((key) => key.id);
+				.map((key) => {
+					return {
+						id: key.id,
+						createdAt: key.createdAt
+					}
+				});
 
-			ids.push(...res);
+			extractedNotes.push(...res);
+			console.log(extractedNotes);
 		}
 
-		// Sort all the results by note id DESC (newest first)
-		ids.sort((a, b) => b - a);
+		// Depending on the ordering requested, return the notes sorted by relevancy as
+		// returned by Meilisearch or order chronologically
+		if (sortByDate) {
+			extractedNotes.sort((a, b) => b.createdAt - a.createdAt);
+		}
 
 		// Fetch the notes from the database until we have enough to satisfy the limit
 		start = 0;
 		const found = [];
-		while (found.length < ps.limit && start < ids.length) {
-			const chunk = ids.slice(start, start + chunkSize);
-			const notes: Note[] = await Notes.find({
+		const noteIDs = extractedNotes.map(note => note.id);
+
+		// Index the ID => index number into a map, so we can sort efficiently later
+		const idIndexMap = new Map(noteIDs.map((id, index) => [id, index]));
+
+		while (found.length < ps.limit && start < noteIDs.length) {
+			const chunk = noteIDs.slice(start, start + chunkSize);
+
+			let query : FindManyOptions = sortByDate ? {
 				where: {
 					id: In(chunk),
 				},
 				order: {
-					id: "DESC",
+					id: "DESC"
+				}
+			} : {
+				where: {
+					id: In(chunk),
 				},
-			});
+			}
+
+			console.log(JSON.stringify(query))
+
+			const notes: Note[] = await Notes.find(query);
+
+			// Re-order the note result according to the noteIDs array (cannot be undefined, we map this earlier)
+			// @ts-ignore
+			notes.sort((a, b) => idIndexMap.get(a.id) - idIndexMap.get(b.id));
 
 			// The notes are checked for visibility and muted/blocked users when packed
 			found.push(...(await Notes.packMany(notes, me)));
 			start += chunkSize;
 		}
 
-		// If we have more results than the limit, trim them
+		// If we have more results than the limit, trim the results down
 		if (found.length > ps.limit) {
 			found.length = ps.limit;
 		}