musescore-downloader/src/file.ts
2020-10-30 14:53:02 -04:00

75 lines
2.1 KiB
TypeScript

/* eslint-disable no-extend-native */
import scoreinfo from './scoreinfo'
import { webpackHook } from './webpack-hook'
const FILE_URL_MODULE_ID = 'iNJA'
const MAGIC_REG = /^\d+(img|mp3|midi)\d(.+)$/
type FileType = 'img' | 'mp3' | 'midi'
const getApiUrl = (id: number, type: FileType, index: number): string => {
// proxy
return `https://musescore.now.sh/api/jmuse?id=${id}&type=${type}&index=${index}`
}
/**
* I know this is super hacky.
*/
let magic: Promise<string> | string = new Promise((resolve) => {
// reserve for future hook update
const target = String.prototype
const method = 'charCodeAt'
const _fn = target[method]
// This script can run before anything on the page,
// so setting this function to be non-configurable and non-writable is no use.
const hookFn = function (i: number) {
const m = this.match(MAGIC_REG)
if (m) {
resolve(m[2])
magic = m[2]
target[method] = _fn // detach
}
return _fn.call(this, i) as number
}
target[method] = hookFn
// make hooked methods "native"
const _toString = Function.prototype['toString']
Function.prototype.toString = function s () {
if (this === hookFn || this === s) {
// "function () {\n [native code]\n}"
return _toString.call(parseInt) as string
}
return _toString.call(this) as string
}
})
export const getFileUrl = async (type: FileType, index = 0): Promise<string> => {
const fileUrlModule = webpackHook(FILE_URL_MODULE_ID, {
'6Ulw' (_, r, t) { // override
t.d(r, 'a', () => {
return type
})
},
'VSrV' (_, r, t) { // override
t.d(r, 'b', () => {
return getApiUrl
})
},
})
const fn: (id: number, index: number, cb: (url: string) => any, magic: string) => string = fileUrlModule.a
if (typeof magic !== 'string') {
// force to retrieve the MAGIC
const el = document.querySelectorAll('.SD7H- > button')[3] as HTMLButtonElement
el.click()
magic = await magic
}
return new Promise((resolve) => {
return fn(scoreinfo.id, index, resolve, magic as string)
})
}