add challenge scripts

2025-09-12 11:19:05 +02:00
parent 81fea4865e
commit 7f33c43169
10 changed files with 321 additions and 0 deletions
--- a/js/common_v=2.js
+++ b/js/common_v=2.js
@@ -0,0 +1,151 @@
+/*
+  NOTE: this just contains user interface logic;
+  there is probably not much interesting stuff here
+*/
+
+let name, n, x, n_old, n_last;
+
+async function init() {
+    const params = (new URL(document.URL)).searchParams;
+    if(params.has('name')) {
+        name = params.get('name');
+    } else {
+        /* missing name, redirect to start screen */
+        location.replace('.');
+        return;
+    }
+    /* people can do more than 2^53 button clicks, so we need big integers */
+    if(params.has('n') && params.has('x')) {
+        n = BigInt(params.get('n'));
+        x = BigInt(params.get('x'));
+    } else {
+        n = 0n;
+        x = 0n;
+    }
+    n_old = 0n;
+    n_last = -1n;
+    if(typeof prepare == 'function') {
+        await prepare();
+    }
+    const button = document.querySelector('button');
+    button.textContent = n;
+    button.addEventListener('click', onClick);
+    setInterval(() => {
+        if(n > n_last) {
+            /* to spare the browser, we do this at most 10 times per second */
+            const params = new URLSearchParams({name, n, x});
+            history.replaceState(null, '', '?' + params);
+            button.textContent = n;
+            n_last = n;
+        }
+    }, 100);
+    communicate();
+}
+
+document.addEventListener('DOMContentLoaded', init);
+
+async function communicate() {
+    const error = document.querySelector('#error');
+    try {
+        /* only submit increased click counts, otherwise just fetch scores */
+        const path = 'server.php' + ((n_last > n_old) ? location.search : '');
+        const result = await fetch(path);
+        if(!result.ok) {
+            throw new Error(`${result.status} ${result.statusText}`);
+        }
+        if(n_last > n_old) {
+            n_old = n_last;
+        }
+        const json = await result.json();
+        if(json.flag && !location.pathname.endsWith('/' + json.flag)) {
+            /* advance to next level */
+            location.replace(json.flag + location.search);
+            return;
+        }
+        if(json.scores) {
+            displayScores(json.scores, json.time);
+        }
+        if(json.error) {
+            throw new Error(json.error);
+        }
+        const timeStr = new Date(json.time * 1000).toLocaleTimeString('de-DE');
+        error.textContent = `Zuletzt aktualisiert: ${timeStr}`;
+    } catch(e) {
+        console.warn(e);
+        error.textContent = e;
+    }
+    setTimeout(communicate, 1000);
+}
+
+function displayScores(scores, time) {
+    const table = document.querySelector('table');
+    while(table.rows.length > 1) {
+        table.deleteRow(-1);
+    }
+    scores.sort((a, b) => {
+        const n_a = BigInt(a.n);
+        const n_b = BigInt(b.n);
+        if(n_a > n_b) {
+            return -1;
+        }
+        if(n_a < n_b) {
+            return 1;
+        }
+        if(a.time < b.time) {
+            return -1;
+        }
+        if(a.time > b.time) {
+            return 1;
+        }
+        return 0;
+    });
+    scores.forEach((entry) => {
+        const row = table.insertRow();
+
+        const nameCell = row.insertCell();
+        /* protect against unicode bidi control characters */
+        const bdi = document.createElement('bdi');
+        bdi.textContent = entry.name;
+        nameCell.appendChild(bdi);
+        nameCell.title = entry.name;
+
+        const timeCell = row.insertCell();
+        const date = new Date(entry.time * 1000);
+        if(time - entry.time < 86400) {
+            timeCell.textContent = date.toLocaleTimeString('de-DE');
+        } else {
+            timeCell.textContent = date.toLocaleDateString('de-DE');
+        }
+        timeCell.title = date.toLocaleString('de-DE');
+
+        const nCell = row.insertCell();
+        nCell.textContent = entry.n;
+        nCell.title = entry.n;
+    });
+}
+
+/* compute SHA-256 digest represented as integer (big endian) */
+async function sha256(str) {
+    const msg = new TextEncoder().encode(str);
+    const buffer = await crypto.subtle.digest('SHA-256', msg);
+    const bytes = new Uint8Array(buffer);
+    let val = 0n;
+    for(const b of bytes) {
+        val = (val << 8n) | BigInt(b);
+    }
+    return val;
+}
+
+/* compute a^k modulo m */
+function pow(a, k, m) {
+    let b = 1n;
+    for(; k; k >>= 1n) {
+        if(k & 1n) {
+            b *= a;
+            b %= m;
+        }
+        a *= a;
+        a %= m;
+    }
+    return b;
+}