// ==UserScript==
// @name         osu!pp
// @namespace    http://nat.moe/
// @version      0.1
// @description  show FC PP on osu info page.
// @author       NAT
// @match        https://osu.ppy.sh/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    var bmid = 0,
        si = document.getElementById('songinfo');

    if(!si) return 0;
    else si = si.children[0];

    try {
       bmid = parseInt(
          si.children[6].children[2].children[3].href
            .split('/')[4]
        );
    } catch (e) {
      // whatever.
    }

    if (bmid == 0) return 0;

    Array.prototype.chunk = function(chunkSize) {
      var R = [];
      for (var i=0; i<this.length; i+=chunkSize)
        R.push(this.slice(i,i+chunkSize));
      return R;
    };

    var api_url = 'https://api.nat.moe/oppai.cgi?' + bmid;
    var apiGet = () => {
      return new Promise(function (resolve, reject) {
        var xhr = new XMLHttpRequest();
        xhr.open('GET', api_url);
        xhr.onload = function () {
          if (this.status == 200) {
            var res = JSON.parse(xhr.response);
            if(res.ok) resolve(res.info);
            else reject({err: res.err});
          }
          else reject({err: xhr.statusText});
        };
        xhr.onerror = function () {
          reject({err: xhr.statusText});
        };
        xhr.send();
      });
    };

    var target_infos = [
      {name: 'FC PP:', prop: 'pp'},
      {name: 'Speed *:', prop: 'speed_stars'},
      {name: 'Aim *:', prop: 'aim_stars'},
      {name: 'Circles:', prop: 'num_circles'},
      {name: 'Sliders:', prop: 'num_sliders'},
      {name: 'Spinners:', prop: 'num_spinners'}
    ];

    var DescTr = function(items, vals) {
      var tr = document.createElement('tr');
      items.forEach((item) => {
        var td_title = document.createElement('td');
        var td_val = document.createElement('td');
        td_title.width = '0%';
        td_val.className = "colour";
        td_title.innerHTML = item.name;
        td_val.innerHTML = vals[item.prop];
        tr.appendChild(td_title);
        tr.appendChild(td_val);
      });
      return tr;
    };

    var handler = (oppai) => {
      target_infos.chunk(3).forEach((infoset) => {
        si.insertBefore(new DescTr(infoset, oppai), si.children[3]);
      });
    };

    apiGet().then(handler).catch(console.log);
})();