https://www.osobni-rust.com/ariadne/javascript/form-utils.js?v=94d6a582

1(function () {
2  async function sha256(input) {
3    const buffer = await crypto.subtle.digest(
4      "SHA-256",
5      new TextEncoder().encode(input)
6    );
7
8    return Array.from(new Uint8Array(buffer), byte =>
9      byte.toString(16).padStart(2, "0")
10    ).join("");
11  }
12
13  async function sha256Nested(input, rounds = 64) {
14    let hash = input;
15
16    for (let i = 0; i < rounds; i++) {
17      hash = await sha256(hash);
18    }
19
20    return hash;
21  }
22
23  function loadToken(input, onDone, silent) {
24    var done = function () { if (onDone) { onDone(); onDone = null; } };
25    if (!silent) input.value = "init";
26    var url = input.getAttribute("data-token-url");
27    if (!url) {
28      done();
29      return;
30    }
31
32    if (!silent) input.value = "loading";
33
34    fetch(url)
35      .then(function (r) {
36        return r.json();
37      })
38      .then(async function (d) {
39        if (d && d.token) {
40          if (!silent) input.value = d.token + "-loaded";
41          let mined = 0;
42          let hash = "";
43          let tokenWithMined = "";
44          do {
45            tokenWithMined = d.token + "-" + mined++;
46            hash = await sha256Nested(tokenWithMined);
47            if (mined % 64 === 0) {
48              if (!silent) input.value = tokenWithMined + "-mining";
49              // yield to browser to frevent GUI freeze
50              await new Promise(function (r) { setTimeout(r, 0); });
51            }
52          } while (!hash.startsWith("00") && mined <= 10000000);
53
54          if (hash.startsWith("0")) {
55            input.value = tokenWithMined;
56          } else {
57            if (!silent) input.value = d.token + "failed";
58            console.error("Proof of work failed: max attempts reached");
59          }
60        }
61      })
62      .catch(function (e) {
63        if (!silent) input.value = "ERR: " + e;
64        console.error(e);
65      })
66      .finally(done);
67  }
68
69  function init() {
70    var inputs = document.querySelectorAll("input[data-token-url]");
71    if (!inputs.length) {
72      return;
73    }
74
75    var pendingByForm = new Map();
76    Array.prototype.forEach.call(inputs, function (input) {
77      var form = input.closest("form");
78      if (!form) return;
79      pendingByForm.set(form, (pendingByForm.get(form) || 0) + 1);
80      form.classList.add("form-token-loading");
81    });
82
83    function done(input) {
84      var form = input.closest("form");
85      if (!form) return;
86      var remaining = (pendingByForm.get(form) || 1) - 1;
87      if (remaining <= 0) {
88        pendingByForm.delete(form);
89        form.classList.remove("form-token-loading");
90      } else {
91        pendingByForm.set(form, remaining);
92      }
93    }
94
95    setTimeout(function () {
96      Array.prototype.forEach.call(inputs, function (input) {
97        loadToken(input, function () {
98          done(input);
99          function scheduleReload() {
100            setTimeout(function () {
101              if (!input.isConnected) return;
102              loadToken(input, scheduleReload, true);
103            }, 10 * 60 * 1000);
104          }
105          scheduleReload();
106        });
107      });
108    }, 1000);
109  }
110
111  if (document.readyState === "loading") {
112    document.addEventListener("DOMContentLoaded", init);
113  } else {
114    init();
115  }
116})();