word/quiz.js

   1 Array.prototype.shuffle = function () {
   2         for (let i = this.length - 1; i > 0; i--) {
   3                 const j = Math.floor(Math.random() * (i + 1)); // random index 0..i
   4                 [this[i], this[j]] = [this[j], this[i]]; // swap elements
   5         }
   6         return this;
   7 };
   8
   9 class WordQuiz {
  10         dataselect(json) {
  11                 this.data = json;
  12                 this.cats = {}; // category lookup
  13                 for (let i in json) {
  14                         let cat = json[i][3];
  15                         if (this.cats[cat]) {
  16                                 this.cats[cat].push(i);
  17                         }
  18                         else {
  19                                 this.cats[cat] = [i];
  20                         }
  21                 }
  22                 return this.datafilter(json);
  23         }
  24
  25         datafilter(json) {
  26                 // find viable rows from json data
  27                 let rows = Object.values(json);
  28
  29                 if (this.preset.cat !== undefined) {
  30                         rows = [];
  31                         let children = this.cats[this.preset.cat];
  32                         for (let loop = 0; children.length && loop < 20; loop++) {
  33                                 rows.push(...children);
  34                                 children = children.map(cat => this.cats[cat]).filter(is => is).flat();
  35                         }
  36                         rows = rows.map(row => json[row]).filter(row => row[2]);
  37                 }
  38                 if (this.preset.level !== undefined) {
  39                         rows = rows.filter(row => row[1] <= this.preset.level);
  40                 }
  41
  42                 {
  43                         let cats = new Set();
  44                         let subcats = rows.map(row => row[3]); // direct parents
  45                         for (let loop = 0; subcats.length && loop < 20; loop++) {
  46                                 subcats.forEach(cat => cats.add(cat));
  47                                 subcats = subcats.map(row => json[row] && json[row][3]).filter(val => val); // recurse grandparents
  48                         }
  49                         rows = rows.filter(row => !cats.has(row[2])); // remove referenced categories
  50                 }
  51                 return rows.shuffle();
  52         }
  53
  54         load(dataurl) {
  55                 this.preset = {};
  56                 let input;
  57                 if (input = window.location.hash.match(/\d+/)) {
  58                         this.preset.cat = input[0];
  59                 }
  60                 if (window.location.hash.match(/a/)) {
  61                         this.preset.level = 3;
  62                 }
  63
  64                 fetch(dataurl).then(res => res.json()).then(json => {
  65                         this.words = this.dataselect(json)
  66                         this.setup();
  67                 });
  68         }
  69
  70         log(...args) {
  71                 this.history.push([new Date().toISOString(), ...args]);
  72         }
  73
  74         stop(...args) {
  75                 this.log(...args);
  76                 window.onbeforeunload = null;
  77                 fetch('/word/report', {method: 'POST', body: JSON.stringify(this.history)});
  78         }
  79
  80         constructor(dataurl) {
  81                 this.load(dataurl);
  82                 this.history = [];
  83                 window.onbeforeunload = e => {
  84                         this.stop('abort');
  85                 };
  86         }
  87 }