file.ts

/* eslint-disable no-extend-native */
/* eslint-disable @typescript-eslint/no-unsafe-return */

import isNodeJs from "detect-node";
import { useTimeout, getFetch } from "./utils";
import { magics } from "./file-magics";

export type FileType = "img" | "mp3" | "midi";

const getApiUrl = (id: number, type: FileType, index: number): string => {
  return `/api/jmuse?id=${id}&type=${type}&index=${index}&v2=1`;
};

/**
 * hard-coded auth tokens
 */
const useBuiltinAuth = (type: FileType): string => {
  switch (type) {
    case "img":
      return "8c022bdef45341074ce876ae57a48f64b86cdcf5";
    case "midi":
      return "38fb9efaae51b0c83b5bb5791a698b48292129e7";
    case "mp3":
      return "63794e5461e4cfa046edfbdddfccc1ac16daffd2";
  }
};

const getApiAuth = async (type: FileType, index: number): Promise<string> => {
  // eslint-disable-next-line no-void
  void index; // unused

  if (isNodeJs) {
    // we cannot intercept API requests in Node.js (as no requests are sent), so go straightforward to the hard-coded tokens
    return useBuiltinAuth(type);
  }

  const magic = magics[type];
  if (magic instanceof Promise) {
    // force to retrieve the MAGIC
    try {
      switch (type) {
        case "midi": {
          const fsBtn = document.querySelector(
            'button[title="Toggle Fullscreen"]'
          ) as HTMLButtonElement;
          const el = fsBtn.parentElement?.parentElement?.querySelector(
            "button"
          ) as HTMLButtonElement;
          el.click();
          break;
        }
        case "mp3": {
          const el = document.querySelector(
            'button[title="Toggle Play"]'
          ) as HTMLButtonElement;
          el.click();
          break;
        }
        case "img": {
          const imgE = document.querySelector("img[src*=score_]");
          const nextE = imgE?.parentElement?.nextElementSibling;
          if (nextE) nextE.scrollIntoView();
          break;
        }
      }
    } catch (err) {
      console.error(err);
      return useBuiltinAuth(type);
    }
  }

  try {
    return await useTimeout(magic, 5 * 1000 /* 5s */);
  } catch {
    console.error(type, "token timeout");
    // try hard-coded tokens
    return useBuiltinAuth(type);
  }
};

export const getFileUrl = async (
  id: number,
  type: FileType,
  index = 0,
  _fetch = getFetch()
): Promise<string> => {
  const url = getApiUrl(id, type, index);
  const auth = await getApiAuth(type, index);

  const r = await _fetch(url, {
    headers: {
      Authorization: auth,
    },
  });

  const { info } = await r.json();
  return info.url as string;
};