word/quiz: category selection from location hash

[sheet.git] / word / quiz.js

diff --git a/word/quiz.js b/word/quiz.js
index 361d075e66391f517b08b8f51f7a12222ef9b954..187aea7e76d72aa2aa3410e8117679cf1e7822f2 100644 (file)
--- a/word/quiz.js
+++ b/word/quiz.js
@@ -8,11 +8,50 @@ Array.prototype.shuffle = function () {
 
 class WordQuiz {
        dataselect(json) {
+               // find viable rows from json data
                let rows = Object.values(json);
+               if (this.preset.cat !== undefined) {
+                       let cats = {}; // category lookup
+                       for (let i in json) {
+                               let cat = json[i][3];
+                               if (!cats[cat]) cats[cat] = [];
+                               cats[cat].push(i)
+                       }
+
+                       rows = [];
+                       let children = cats[this.preset.cat];
+                       for (let loop = 0; children.length && loop < 20; loop++) {
+                               rows.push(...children);
+                               children = children.map(cat => cats[cat]).filter(is => is).flat();
+                       }
+                       rows = rows.map(row => json[row]).filter(row => row[2]);
+               }
+               if (this.preset.level !== undefined) {
+                       rows = rows.filter(row => row[1] <= this.preset.level);
+               }
+
+               {
+                       let cats = new Set();
+                       let subcats = rows.map(row => row[3]); // direct parents
+                       for (let loop = 0; subcats.length && loop < 20; loop++) {
+                               subcats.forEach(cat => cats.add(cat));
+                               subcats = subcats.map(row => json[row] && json[row][3]).filter(val => val); // recurse grandparents
+                       }
+                       rows = rows.filter(row => !cats.has(row[2])); // remove referenced categories
+               }
                return rows.shuffle();
        }
 
        load(dataurl) {
+               this.preset = {};
+               let input;
+               if (input = window.location.hash.match(/\d+/)) {
+                       this.preset.cat = input[0];
+               }
+               if (window.location.hash.match(/a/)) {
+                       this.preset.level = 2;
+               }
+
                fetch(dataurl).then(res => res.json()).then(json => {
                        this.words = this.dataselect(json)
                        this.setup();