[feat] added a naive way to parse mod metadata (#855)

src/__tests__/unit/mods.helpers.test.ts

@@ -0,0 +1,62 @@
+import { parseMetadata } from "main/helpers/mods.helpers";
+import path from "path";
+
+const TEST_FOLDER = path.resolve(__dirname, "..", "assets", "dll");
+
+describe("Test mods.helpers.test", () => {
+
+    test("parseMetadata of BSML.dll", async () => {
+        const filepath = path.join(TEST_FOLDER, "BSML.dll");
+        const data = await parseMetadata(filepath);
+
+        expect(data).toBeTruthy();
+
+        expect(data.name).toBe("BeatSaberMarkupLanguage");
+        expect(data.id).toBe("BeatSaberMarkupLanguage");
+        expect(data.author).toBeTruthy();
+        expect(data.version).toBeTruthy();
+        expect(data.gameVersion).toBeTruthy();
+    });
+
+    test("parseMetadata of Bugsmash.dll", async () => {
+        const filepath = path.join(TEST_FOLDER, "Bugsmash.dll");
+        const data = await parseMetadata(filepath);
+
+        expect(data).toBeTruthy();
+
+        expect(data.name).toBe("Bugsmash");
+        expect(data.id).toBe("Bugsmash");
+        expect(data.author).toBeTruthy();
+        expect(data.version).toBeTruthy();
+        expect(data.gameVersion).toBeTruthy();
+    });
+
+    test("parseMetadata of PlaylistManager.dll", async () => {
+        const filepath = path.join(TEST_FOLDER, "PlaylistManager.dll");
+        const data = await parseMetadata(filepath);
+
+        expect(data).toBeTruthy();
+
+        expect(data.name).toBe("PlaylistManager");
+        expect(data.id).toBe("PlaylistManager");
+        expect(data.author).toBeTruthy();
+        expect(data.version).toBeTruthy();
+        expect(data.gameVersion).toBeTruthy();
+
+    });
+
+    test("parseMetadata of SongCore.dll", async () => {
+        const filepath = path.join(TEST_FOLDER, "SongCore.dll");
+        const data = await parseMetadata(filepath);
+
+        expect(data).toBeTruthy();
+
+        expect(data.name).toBe("SongCore");
+        expect(data.id).toBe("SongCore");
+        expect(data.author).toBeTruthy();
+        expect(data.version).toBeTruthy();
+        expect(data.gameVersion).toBeTruthy();
+    });
+
+});
+

src/main/helpers/mods.helpers.ts

@@ -0,0 +1,57 @@
+import { readFile } from "fs-extra";
+import { ModMetadata } from "shared/models/mods/mod.interface";
+
+// NOTE: getMetadata is slow since its using a search string and object parsing.
+// Ways to optimize:
+//  - Find a way to locate the metadata string within the pdb/dll file
+//  - Correct object sizing, since the first byte does not match sometimes with the size somehow
+
+// ref: https://raw.githubusercontent.com/bsmg/BSIPA-MetadataFileSchema/master/Schema.json
+const SEARCH_ARRAY = [
+    0x22, 0x24, 0x73, 0x63, 0x68,
+    0x65, 0x6D, 0x61, 0x22
+].reverse(); // '"$schema"'
+
+export async function parseMetadata(filepath: string): Promise<ModMetadata | null> {
+    const data = await readFile(filepath);
+
+    // Find the word SEARCH_ARRAY from end to start of the buffer data
+    // NOTE: Inefficient algorithm
+    let start = data.length - 1;
+    for (let i = 0; start >= 0; --start) {
+      if (data[start] !== SEARCH_ARRAY[i]) {
+        i = 0;
+      } else if (++i === SEARCH_ARRAY.length) {
+        break;
+      }
+    }
+
+    if (start < 4) {
+        return null;
+    }
+
+    // Search for the starting left curly brace '{'
+    while (data[--start] !== 0x7B);
+
+    // Find the ending right curly brace '}'
+    // NOTE: Inefficient algorithm
+    let braces = 1;
+    let end = start + 1;
+    for (; end < data.length && braces > 0; ++end) {
+        if (data[end] === 0x7B) { // {
+            ++braces;
+        } else if (data[end] === 0x7D) { // }
+            --braces;
+        }
+    }
+
+    // Does not work with every dll (eg. Bugsmash.dll)
+    // const length = (data[start - 1] << 24)
+    //              + (data[start - 2] << 16)
+    //              + (data[start - 3] <<  8)
+    //              + (data[start - 4]);
+    // const end = start + length;
+
+    return JSON.parse(data.toString(undefined, start, end)) as ModMetadata;
+}
+

src/shared/models/mods/mod.interface.ts

@@ -100,3 +100,27 @@ export interface BbmUserAPIResponse {
     createdAt?: Date;
     updatedAt?: Date;
 }
+
+// https://raw.githubusercontent.com/bsmg/BSIPA-MetadataFileSchema/master/Schema.json
+export interface ModMetadata {
+    name: string;
+    id: string | null;
+    version: string;
+    gameVersion: string;
+    description: string;
+    author: string;
+    dependsOn?: Record<string, string>;
+    conflictsWith?: Record<string, string>;
+    loadAfter?: string[];
+    loadBefore?: string[];
+    feature?: Record<string, string>;
+    icon?: string;
+    files?: string[];
+    links?: {
+        "project-home"?: string;
+        "project-source"?: string;
+        donate?: string;
+    };
+    misc?: Record<string, string>;
+}
+