From edf8187ba101585c263cf6e44b74f7b49131d629 Mon Sep 17 00:00:00 2001
From: Klemek <klemek@outlook.fr>
Date: Mon, 5 Jun 2023 16:35:46 +0200
Subject: [PATCH] add difficulty

---
 main.js | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 129 insertions(+), 2 deletions(-)

diff --git a/main.js b/main.js
index 03b67db..6356894 100644
--- a/main.js
+++ b/main.js
@@ -16,6 +16,107 @@ function shuffle(array) {
     return array;
 }
 
+const levenshtein = (function () {
+    function _min(d0, d1, d2, bx, ay) {
+        return d0 < d1 || d2 < d1
+            ? d0 > d2
+                ? d2 + 1
+                : d0 + 1
+            : bx === ay
+                ? d1
+                : d1 + 1;
+    }
+
+    return function (a, b) {
+        if (a === b) {
+            return 0;
+        }
+
+        if (a.length > b.length) {
+            var tmp = a;
+            a = b;
+            b = tmp;
+        }
+
+        var la = a.length;
+        var lb = b.length;
+
+        while (la > 0 && (a.charCodeAt(la - 1) === b.charCodeAt(lb - 1))) {
+            la--;
+            lb--;
+        }
+
+        var offset = 0;
+
+        while (offset < la && (a.charCodeAt(offset) === b.charCodeAt(offset))) {
+            offset++;
+        }
+
+        la -= offset;
+        lb -= offset;
+
+        if (la === 0 || lb < 3) {
+            return lb;
+        }
+
+        var x = 0;
+        var y;
+        var d0;
+        var d1;
+        var d2;
+        var d3;
+        var dd;
+        var dy;
+        var ay;
+        var bx0;
+        var bx1;
+        var bx2;
+        var bx3;
+
+        var vector = [];
+
+        for (y = 0; y < la; y++) {
+            vector.push(y + 1);
+            vector.push(a.charCodeAt(offset + y));
+        }
+
+        var len = vector.length - 1;
+
+        for (; x < lb - 3;) {
+            bx0 = b.charCodeAt(offset + (d0 = x));
+            bx1 = b.charCodeAt(offset + (d1 = x + 1));
+            bx2 = b.charCodeAt(offset + (d2 = x + 2));
+            bx3 = b.charCodeAt(offset + (d3 = x + 3));
+            dd = (x += 4);
+            for (y = 0; y < len; y += 2) {
+                dy = vector[y];
+                ay = vector[y + 1];
+                d0 = _min(dy, d0, d1, bx0, ay);
+                d1 = _min(d0, d1, d2, bx1, ay);
+                d2 = _min(d1, d2, d3, bx2, ay);
+                dd = _min(d2, d3, dd, bx3, ay);
+                vector[y] = dd;
+                d3 = d2;
+                d2 = d1;
+                d1 = d0;
+                d0 = dy;
+            }
+        }
+
+        for (; x < lb;) {
+            bx0 = b.charCodeAt(offset + (d0 = x));
+            dd = ++x;
+            for (y = 0; y < len; y += 2) {
+                dy = vector[y];
+                vector[y] = dd = _min(dy, d0, dd, bx0, vector[y + 1]);
+                d0 = dy;
+            }
+        }
+
+        return dd;
+    };
+})();
+
 
 let app = {
     data() {
@@ -41,9 +142,25 @@ let app = {
     methods: {
         showApp(data) {
             this.data = data;
+            this.data.forEach((value, id) => {
+                value.distances = this.getDistances(id);
+                value.sumDistances = value.distances.reduce((s, a) => s + a, 0);
+            });
+            console.log(this.data);
             document.getElementById('app').setAttribute('style', '');
             this.newQuestion();
         },
+        getDistances(id0) {
+            return this.data.map((value, id) => {
+                if (id === id0) {
+                    return 0;
+                }
+                if (value.distances) {
+                    return value.distances[id0];
+                }
+                return 64 - levenshtein(this.data[id0].name, value.name);
+            });
+        },
         click(i) {
             if (!this.show_results) {
                 this.answers[i].clicked = true;
@@ -61,13 +178,23 @@ let app = {
         getRandomDataIndex() {
             return Math.floor(Math.random() * this.data.length)
         },
+        getWeightedRandomDataIndex(id0) {
+            let v = Math.random() * this.data[id0].sumDistances;
+            for (let i = 0; i < this.data[id0].distances.length; i++) {
+                v -= this.data[id0].distances[i];
+                if (v <= 0) {
+                    return i;
+                }
+            }
+            return id0;
+        },
         newQuestion() {
             this.question = this.getRandomDataIndex();
             const ids = [this.question];
             for (let i = 0; i < 3; i++) {
-                let candidate = this.getRandomDataIndex();
+                let candidate = this.getWeightedRandomDataIndex(this.question);
                 while (ids.includes(candidate)) {
-                    candidate = this.getRandomDataIndex();
+                    candidate = this.getWeightedRandomDataIndex(this.question);
                 }
                 ids.push(candidate);
             }