feat: Implemented romm saves for dolphin and xenia

feat: Implemented save backups for emulatorjs
fix: Added support for rar archives
fix: Moved to individual ini adjustments for pcsx2 and ppsspp to allow for user editing of configs

src/bun/api/plugins/builtin/emulators/com.simeonradivoev.gameflow.xenia/utils.ts

@@ -0,0 +1,141 @@
+import { join } from "path";
+import { platform } from "os";
+
+const SECTOR_SIZE = 0x800;
+const MAGIC = "MICROSOFT*XBOX*MEDIA";
+
+const PARTITION_OFFSETS: Record<string, number> = {
+    XSF: 0x0,
+    GDF: 0xFD90000,
+    XGD3: 0x2080000,
+};
+
+async function readBytes (file: ReturnType<typeof Bun.file>, offset: number, length: number): Promise<Buffer>
+{
+    return Buffer.from(await file.slice(offset, offset + length).arrayBuffer());
+}
+
+async function parseTitleIdFromXexReader (
+    read: (offset: number, length: number) => Promise<Buffer>
+): Promise<string>
+{
+    // Read just the fixed header (magic + flags + offsets + header count)
+    const header = await read(0, 0x18);
+    if (header.toString("ascii", 0, 4) !== "XEX2")
+    {
+        throw new Error("Not a valid XEX2 file");
+    }
+
+    const headerCount = header.readUInt32BE(0x14);
+    const EXEC_INFO_KEY = 0x40006;
+
+    // Read the optional header table
+    const table = await read(0x18, headerCount * 8);
+
+    for (let i = 0; i < headerCount; i++)
+    {
+        const key = table.readUInt32BE(i * 8);
+        const valueOrOffset = table.readUInt32BE(i * 8 + 4);
+
+        if (key === EXEC_INFO_KEY)
+        {
+            // valueOrOffset is a file offset — read the exec info struct there
+            // TitleID is at +0x0C within it
+            const execInfo = await read(valueOrOffset, 0x18);
+            return execInfo.readUInt32BE(0x0C)
+                .toString(16).toUpperCase().padStart(8, "0");
+        }
+    }
+
+    throw new Error("Execution info header not found in XEX");
+}
+
+async function titleIdFromXexFile (xexPath: string): Promise<string>
+{
+    const file = Bun.file(xexPath);
+    return parseTitleIdFromXexReader((offset, length) =>
+        readBytes(file, offset, length)
+    );
+}
+
+async function titleIdFromIso (isoPath: string): Promise<string>
+{
+    const file = Bun.file(isoPath);
+    const fileSize = file.size;
+
+    for (const partitionOffset of Object.values(PARTITION_OFFSETS))
+    {
+        const vdOffset = partitionOffset + 0x20 * SECTOR_SIZE;
+        if (vdOffset + 28 > fileSize) continue;
+
+        const vd = await readBytes(file, vdOffset, 28);
+        if (vd.toString("ascii", 0, 20) !== MAGIC) continue;
+
+        const rootSector = vd.readUInt32LE(20);
+        const rootSize = vd.readUInt32LE(24);
+        const rootOffset = partitionOffset + rootSector * SECTOR_SIZE;
+        const dir = await readBytes(file, rootOffset, rootSize);
+
+        let pos = 0;
+        while (pos < dir.length)
+        {
+            if (dir[pos] === 0xFF) break;
+            if (pos + 14 > dir.length) break;
+
+            const nameLen = dir[pos + 13];
+            if (nameLen === 0 || nameLen === 0xFF) break;
+            if (pos + 14 + nameLen > dir.length) break;
+
+            const name = dir.toString("ascii", pos + 14, pos + 14 + nameLen);
+            const fileSector = dir.readUInt32LE(pos + 4);
+
+            if (name.toLowerCase() === "default.xex")
+            {
+                const xexBase = partitionOffset + fileSector * SECTOR_SIZE;
+                // Reader that translates relative XEX offsets to absolute ISO offsets
+                return parseTitleIdFromXexReader((offset, length) =>
+                    readBytes(file, xexBase + offset, length)
+                );
+            }
+
+            const entryLen = 14 + nameLen;
+            pos += (entryLen + 3) & ~3;
+        }
+    }
+
+    throw new Error("Not a valid Xbox 360 ISO or default.xex not found");
+}
+
+async function titleIdFromFolder (folderPath: string): Promise<string>
+{
+    return titleIdFromXexFile(join(folderPath, "default.xex"));
+}
+
+type XeniaRomType = "iso" | "xex" | "folder";
+
+function detectRomType (romPath: string): XeniaRomType
+{
+    const lower = romPath.toLowerCase();
+    if (lower.endsWith(".iso")) return "iso";
+    if (lower.endsWith(".xex")) return "xex";
+    return "folder"; // extracted game folder containing default.xex
+}
+
+async function getTitleId (romPath: string): Promise<string>
+{
+    switch (detectRomType(romPath))
+    {
+        case "iso": return titleIdFromIso(romPath);
+        case "xex": return titleIdFromXexFile(romPath);
+        case "folder": return titleIdFromFolder(romPath);
+    }
+}
+
+export async function getXeniaSavePaths (
+    romPath: string,
+    xeniaDir: string
+): Promise<string>
+{
+    const titleId = await getTitleId(romPath);
+    return join(xeniaDir, titleId);
+};