From 21d5002575065cfbb286245e2f78f3a3957d4a3c Mon Sep 17 00:00:00 2001
From: Xmader <xmader@outlook.com>
Date: Thu, 22 Oct 2020 16:52:33 -0400
Subject: [PATCH] fix: auth magic

---
 src/file.ts | 32 ++++++++++++++++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/file.ts b/src/file.ts
index 83a710b..10d6a5d 100644
--- a/src/file.ts
+++ b/src/file.ts
@@ -11,6 +11,27 @@ const getApiUrl = (id: number, type: FileType, index: number): string => {
   return `https://musescore.now.sh/api/jmuse?id=${id}&type=${type}&index=${index}`
 }
 
+/**
+ * I know this is super hacky.
+ */
+let magic: Promise<string> | string = new Promise((resolve) => {
+  const reg = '^\\d+(img|mp3|midi)\\d(\\w+)$'
+
+  const _encode = encodeURIComponent
+
+  window.encodeURIComponent = (s) => {
+    const m = s.toString().match(reg)
+    if (m) {
+      // the auth string will be encoded using `encodeURIComponent` before `md5`,
+      // so hook here
+      resolve(m[2])
+      magic = m[2]
+      window.encodeURIComponent = _encode // detach
+    }
+    return _encode(s)
+  }
+})
+
 export const getFileUrl = async (type: FileType, index = 0): Promise<string> => {
   const fileUrlModule = webpackHook(FILE_URL_MODULE_ID, {
     '6Ulw' (_, r, t) { // override
@@ -25,9 +46,16 @@ export const getFileUrl = async (type: FileType, index = 0): Promise<string> =>
     },
   })
 
-  const fn: (id: number, index: number, cb: (url: string) => any) => string = fileUrlModule.default
+  const fn: (id: number, index: number, cb: (url: string) => any, magic: string) => string = fileUrlModule.default
+
+  if (typeof magic !== 'string') {
+    // force to retrieve the MAGIC
+    const el = document.querySelectorAll('._13vRI')[6] as HTMLButtonElement
+    el.click()
+    magic = await magic
+  }
 
   return new Promise((resolve) => {
-    return fn(scoreinfo.id, index, resolve)
+    return fn(scoreinfo.id, index, resolve, magic as string)
   })
 }