script.js

const pwInput = document.getElementById('pw');
const dialFill = document.getElementById('dialFill');
const dialWrap = document.getElementById('dialWrap');
const scoreNum = document.getElementById('scoreNum');
const scoreLabel = document.getElementById('scoreLabel');
const strengthTag = document.getElementById('strengthTag');
const strengthText = document.getElementById('strengthText');
const crackTimeEl = document.getElementById('crackTime');
const hint = document.getElementById('hint');
const hintText = document.getElementById('hintText');

const CIRC = 2 * Math.PI * 90; // 565.48

const COMMON = new Set(["123456","password","123456789","12345678","12345","qwerty",
  "abc123","111111","123123","admin","letmein","welcome","monkey","football",
  "iloveyou","000000","password1","1234567","dragon","master","login"]);

function evaluate(pw){
  const checks = {
    len:   pw.length >= 8,
    upper: /[A-Z]/.test(pw),
    lower: /[a-z]/.test(pw),
    num:   /[0-9]/.test(pw),
    sym:   /[^A-Za-z0-9]/.test(pw),
    common: !COMMON.has(pw.toLowerCase())
  };

  let score = 0;
  if (pw.length >= 8) score += 20;
  if (pw.length >= 12) score += 15;
  if (pw.length >= 16) score += 10;
  if (checks.lower) score += 10;
  if (checks.upper) score += 15;
  if (checks.num) score += 15;
  if (checks.sym) score += 15;
  if (!checks.common) score = Math.min(score, 20);
  if (pw.length === 0) score = 0;

  return { checks, score: Math.max(0, Math.min(100, score)) };
}

function crackTimeEstimate(pw){
  if (!pw.length) return "—";
  let charset = 0;
  if (/[a-z]/.test(pw)) charset += 26;
  if (/[A-Z]/.test(pw)) charset += 26;
  if (/[0-9]/.test(pw)) charset += 10;
  if (/[^A-Za-z0-9]/.test(pw)) charset += 32;
  if (charset === 0) return "—";

  const combos = Math.pow(charset, pw.length);
  const guessesPerSecond = 1e10; // offline attack estimate
  let seconds = combos / guessesPerSecond / 2;

  if (COMMON.has(pw.toLowerCase())) return "Instantly";

  const units = [
    ["century", 60*60*24*365*100],
    ["year", 60*60*24*365],
    ["day", 60*60*24],
    ["hour", 60*60],
    ["minute", 60],
    ["second", 1]
  ];
  for (const [name, size] of units){
    if (seconds >= size){
      const val = Math.floor(seconds / size);
      return val > 999 ? "Centuries" : `${val.toLocaleString()} ${name}${val===1?'':'s'}`;
    }
  }
  return "Instantly";
}

function setChecklistItem(id, met){
  document.getElementById(id).classList.toggle('met', met);
}

function update(){
  const pw = pwInput.value;
  const { checks, score } = evaluate(pw);

  setChecklistItem('chk-len', checks.len);
  setChecklistItem('chk-upper', checks.upper);
  setChecklistItem('chk-lower', checks.lower);
  setChecklistItem('chk-num', checks.num);
  setChecklistItem('chk-sym', checks.sym);
  setChecklistItem('chk-common', checks.common);

  const offset = CIRC - (CIRC * score / 100);
  dialFill.style.strokeDashoffset = offset;

  let color, label, tagText;
  if (pw.length === 0){
    color = 'rgba(22,35,58,0.15)'; label = 'Empty'; tagText = 'Enter a password';
  } else if (score < 40){
    color = 'var(--danger)'; label='Weak'; tagText='Weak — easy to guess';
  } else if (score < 70){
    color = 'var(--amber)'; label='Medium'; tagText='Medium — getting there';
  } else if (score < 90){
    color = 'var(--good)'; label='Strong'; tagText='Strong — nicely done';
  } else {
    color = 'var(--great)'; label='Very Strong'; tagText='Very strong — vault secured';
  }
  dialFill.style.stroke = color;
  scoreNum.innerHTML = score + '<span style="font-size:15px;">/100</span>';
  scoreLabel.textContent = label;
  strengthTag.style.color = color;
  strengthTag.style.background = pw.length ? color + '20' : 'rgba(22,35,58,0.08)';
  strengthText.textContent = tagText;

  dialWrap.classList.toggle('unlocked', score >= 70);

  crackTimeEl.textContent = crackTimeEstimate(pw);

  if (pw.length > 0 && score < 70){
    let tip = "";
    if (!checks.common) tip = "This is a widely used password — attackers try these first.";
    else if (!checks.len) tip = "Add more characters — length matters more than complexity.";
    else if (!checks.upper) tip = "Mix in an uppercase letter.";
    else if (!checks.num) tip = "Add at least one number.";
    else if (!checks.sym) tip = "Add a symbol like ! @ # or %.";
    else tip = "Try combining a longer phrase with a number and symbol.";
    hintText.textContent = tip;
    hint.classList.add('show');
  } else {
    hint.classList.remove('show');
  }
}

pwInput.addEventListener('input', update);

document.getElementById('toggleVis').addEventListener('click', () => {
  pwInput.type = pwInput.type === 'password' ? 'text' : 'password';
});

document.getElementById('copyBtn').addEventListener('click', async (e) => {
  if (!pwInput.value) return;
  try {
    await navigator.clipboard.writeText(pwInput.value);
    const btn = e.currentTarget;
    btn.classList.add('copied');
    const original = btn.innerHTML;
    btn.innerHTML = 'Copied ✓';
    setTimeout(() => { btn.classList.remove('copied'); btn.innerHTML = original; }, 1400);
  } catch(err){ /* clipboard not available */ }
});

document.getElementById('generateBtn').addEventListener('click', () => {
  const lower = "abcdefghijkmnpqrstuvwxyz";
  const upper = "ABCDEFGHJKLMNPQRSTUVWXYZ";
  const nums  = "23456789";
  const syms  = "!@#$%^&*?-_";
  const all = lower + upper + nums + syms;
  let pw = [
    lower[Math.floor(Math.random()*lower.length)],
    upper[Math.floor(Math.random()*upper.length)],
    nums[Math.floor(Math.random()*nums.length)],
    syms[Math.floor(Math.random()*syms.length)]
  ];
  for (let i = 0; i < 10; i++){
    pw.push(all[Math.floor(Math.random()*all.length)]);
  }
  // shuffle
  for (let i = pw.length -1; i>0; i--){
    const j = Math.floor(Math.random()*(i+1));
    [pw[i], pw[j]] = [pw[j], pw[i]];
  }
  pwInput.value = pw.join('');
  pwInput.type = 'text';
  update();
});

update();