Enhance bancho mirror support

server/src/controllers/api/index.ts

@@ -2,6 +2,7 @@ import { t } from "elysia";
 
 import type { App } from "../../app";
 import { BeatmapsManagerPlugin } from "../../plugins/beatmapManager";
+import { BEATMAPS_SEARCH_MAX_RESULTS_LIMIT } from "../../types/general/api";
 
 export default (app: App) => {
   app.use(BeatmapsManagerPlugin)
@@ -121,7 +122,12 @@ export default (app: App) => {
       async ({ BeatmapsManagerInstance, query, set }) => {
         // TODO: Add another search endpoint which would parse cursors instead of pages, to create compatibility with bancho api;
 
+        if (query.limit && (query.limit > BEATMAPS_SEARCH_MAX_RESULTS_LIMIT || query.limit < 1)) {
+          throw new Error(`Limit is too high. Maximum limit is ${BEATMAPS_SEARCH_MAX_RESULTS_LIMIT}`);
+        }
+
         const data = await BeatmapsManagerInstance.searchBeatmapsets({
+          limit: query.limit ?? 50,
           ...query,
         });
 
@@ -135,7 +141,7 @@ export default (app: App) => {
       {
         query: t.Object({
           query: t.Optional(t.String()),
-          limit: t.Optional(t.Numeric()),
+          limit: t.Optional(t.Numeric({ min: 1, max: BEATMAPS_SEARCH_MAX_RESULTS_LIMIT })),
           offset: t.Optional(t.Numeric()),
           status: t.Optional(t.Array(t.Numeric())),
           mode: t.Optional(t.Numeric()),

server/src/core/domains/osu.ppy.sh/bancho.client.ts

@@ -1,3 +1,6 @@
+import qs from "qs";
+
+import { BEATMAPS_SEARCH_MAX_RESULTS_LIMIT } from "../../../types/general/api";
 import type { Beatmap, Beatmapset } from "../../../types/general/beatmap";
 import logger from "../../../utils/logger";
 import { BaseClient } from "../../abstracts/client/base-client.abstract";
@@ -8,12 +11,16 @@ import type {
   GetBeatmapsetsByBeatmapIdsOptions,
   GetBeatmapsOptions,
   ResultWithStatus,
+  SearchBeatmapsetsOptions,
 } from "../../abstracts/client/base-client.types";
 import {
   ClientAbilities,
 } from "../../abstracts/client/base-client.types";
 import { BanchoService } from "./bancho-client.service";
-import type { BanchoBeatmap, BanchoBeatmapset } from "./bancho-client.types";
+import type { BanchoBeatmap, BanchoBeatmapset, BanchoBeatmapsetSearchResult } from "./bancho-client.types";
+
+const BANCHO_SEARCH_PAGE_SIZE = 50;
+const BANCHO_SEARCH_PAGES_LIMIT = 200;
 
 export class BanchoClient extends BaseClient {
   private readonly banchoService = new BanchoService(this.baseApi);
@@ -24,21 +31,29 @@ export class BanchoClient extends BaseClient {
         baseUrl: "https://osu.ppy.sh",
         abilities: [
           ClientAbilities.GetBeatmapById,
+          ClientAbilities.GetBeatmapByHash,
           ClientAbilities.GetBeatmapSetById,
           ClientAbilities.GetBeatmaps,
           ClientAbilities.DownloadOsuBeatmap,
           ClientAbilities.GetBeatmapsetsByBeatmapIds,
+          ClientAbilities.SearchBeatmapsets,
         ],
       },
       {
+        headers: {
+          remaining: "x-ratelimit-remaining",
+          limit: "x-ratelimit-limit",
+        },
         rateLimits: [
           {
             abilities: [
               ClientAbilities.GetBeatmapById,
+              ClientAbilities.GetBeatmapByHash,
               ClientAbilities.GetBeatmapSetById,
               ClientAbilities.GetBeatmaps,
               ClientAbilities.DownloadOsuBeatmap,
               ClientAbilities.GetBeatmapsetsByBeatmapIds,
+              ClientAbilities.SearchBeatmapsets,
             ],
             routes: ["/"],
             limit: 1200,
@@ -67,6 +82,9 @@ export class BanchoClient extends BaseClient {
     if (ctx.beatmapId) {
       return await this.getBeatmapById(ctx.beatmapId);
     }
+    else if (ctx.beatmapHash) {
+      return await this.getBeatmapByHash(ctx.beatmapHash);
+    }
 
     throw new Error("Invalid arguments");
   }
@@ -151,6 +169,61 @@ export class BanchoClient extends BaseClient {
     return { result: result.data, status: result.status };
   }
 
+  async searchBeatmapsets(
+    ctx: SearchBeatmapsetsOptions,
+  ): Promise<ResultWithStatus<Beatmapset[]>> {
+    const page = Math.floor((ctx.offset ?? 0) / BANCHO_SEARCH_PAGE_SIZE) + 1;
+
+    if (page > BANCHO_SEARCH_PAGES_LIMIT
+      || (ctx.limit && ctx.limit > BANCHO_SEARCH_PAGE_SIZE && page === BANCHO_SEARCH_PAGES_LIMIT)) {
+      return { result: null, status: 500 }; // Bancho API has a limit of 200 pages
+    }
+
+    const result = await this.api.get<BanchoBeatmapsetSearchResult>(`api/v2/beatmapsets/search`, {
+      config: {
+        headers: {
+          Authorization: `Bearer ${await this.osuApiKey}`,
+        },
+        params: {
+          query: ctx.query,
+          page,
+          status: ctx.status,
+          mode: ctx.mode,
+        },
+        paramsSerializer: params =>
+          qs.stringify(params, { indices: false }),
+      },
+    });
+
+    if (!result || result.status !== 200 || !result.data) {
+      return { result: null, status: result?.status ?? 500 };
+    }
+
+    let { beatmapsets } = result.data;
+    let additionalBeatmapsets: BanchoBeatmapset[] = [];
+
+    if (ctx.limit && ctx.limit <= BEATMAPS_SEARCH_MAX_RESULTS_LIMIT) {
+      if (ctx.limit < BANCHO_SEARCH_PAGE_SIZE) {
+        beatmapsets = beatmapsets.slice(0, ctx.limit);
+      }
+
+      if (ctx.limit > BANCHO_SEARCH_PAGE_SIZE && page < BANCHO_SEARCH_PAGES_LIMIT) {
+        additionalBeatmapsets = await this.searchBeatmapsets({
+          ...ctx,
+          limit: ctx.limit - beatmapsets.length,
+          offset: (ctx.offset ?? 0) + beatmapsets.length,
+        }).then(result => result.result ?? []);
+      }
+    }
+
+    return {
+      result: [...additionalBeatmapsets, ...(beatmapsets.map((b: BanchoBeatmapset) =>
+        this.convertService.convertBeatmapset(b),
+      ))],
+      status: result.status,
+    };
+  }
+
   private async getBeatmapSetById(
     beatmapSetId: number,
   ): Promise<ResultWithStatus<Beatmapset>> {
@@ -199,6 +272,27 @@ export class BanchoClient extends BaseClient {
     };
   }
 
+  private async getBeatmapByHash(
+    beatmapHash: string,
+  ): Promise<ResultWithStatus<Beatmap>> {
+    const result = await this.api.get<BanchoBeatmap>(`api/v2/beatmaps/lookup?checksum=${beatmapHash}`, {
+      config: {
+        headers: {
+          Authorization: `Bearer ${await this.osuApiKey}`,
+        },
+      },
+    });
+
+    if (!result || result.status !== 200 || !result.data) {
+      return { result: null, status: result?.status ?? 500 };
+    }
+
+    return {
+      result: this.convertService.convertBeatmap(result.data),
+      status: result.status,
+    };
+  }
+
   private get osuApiKey() {
     return this.banchoService.getBanchoClientToken();
   }

server/src/core/managers/mirrors/mirrors.manager.ts

@@ -328,11 +328,32 @@ export class MirrorsManager {
       )
       .filter(client => !ignore || !ignore.includes(client));
 
-    const client = this.getClientByWeight(criteria, clients);
+    const isSearchCriteria = criteria === ClientAbilities.SearchBeatmapsets;
+
+    const client = isSearchCriteria
+      ? this.getClientForSearchEndpoint(clients)
+      : this.getClientByWeight(criteria, clients);
 
     return client;
   }
 
+  // We want to prioritise a single mirror for all search endpoints while it's available to have consistent results from page to page.
+  private getClientForSearchEndpoint(clients: MirrorClient[]): MirrorClient | null {
+    const minoClient = clients.find(client => client.client.clientConfig.baseUrl === "https://us.catboy.best"
+      || client.client.clientConfig.baseUrl === "https://catboy.best"); // TODO: I don't like how we address them by url, should be addressed later.
+
+    if (minoClient) {
+      return minoClient;
+    }
+
+    const banchoClient = clients.find(client => client.client.clientConfig.baseUrl === "https://osu.ppy.sh");
+    if (banchoClient) {
+      return banchoClient;
+    }
+
+    return this.getClientByWeight(ClientAbilities.SearchBeatmapsets, clients);
+  }
+
   private getClientByWeight(
     criteria: ClientAbilities,
     clients: MirrorClient[],

server/src/types/general/api.ts

@@ -0,0 +1 @@
+export const BEATMAPS_SEARCH_MAX_RESULTS_LIMIT = 100;