const gensaltBtn = document.getElementById('gensaltBtn');
const algorithm = document.getElementById('algorithm');
const password = document.getElementById('password');
const salt = document.getElementById('salt');
const hashBtn = document.getElementById('hashBtn');
const result = document.getElementById('result');
const clearBtn = document.getElementById('clearBtn');
const resultBtn = document.getElementById('resultBtn');
const username = document.getElementById('username');

const MIN_PASS_LEN = 16;
const MIN_SALT_LEN = 8;
const MAX_SALT_LEN = 16;

gensaltBtn.addEventListener('click', async () => {
    const len = MAX_SALT_LEN; // can be adjusted or user-defined
    const res = await fetch('/gensalt?length=' + len);
    if (!res.ok) { alert('Could not generate salt'); return; }
    const data = await res.json();
    salt.value = data.salt;
});

const updateUI = () => {
    const isCopyparty = algorithm.value === 'argon2_copyparty';

    salt.disabled = isCopyparty;
    gensaltBtn.disabled = isCopyparty;
    username.disabled = !isCopyparty;

    if (isCopyparty) {
        salt.value = "LVZ1TJMdAIdLyBla6nWDexFt";
        salt.style.opacity = "0.5";
    } else {
        salt.value = "";
        salt.style.opacity = "";
        username.value = "";
    }
};

algorithm.addEventListener('change', updateUI);
window.addEventListener('DOMContentLoaded', updateUI);

hashBtn.addEventListener('click', async () => {
    const pass = password.value || '';
    const s = salt.value || '';
    const alg = algorithm.value;
    const usr = username.value || '';

    if (pass.length < MIN_PASS_LEN) { 
        alert('Password must be at least ' + MIN_PASS_LEN + ' characters');
        return; 
    }

    if (alg !== 'argon2_copyparty') {
        if (s.length < MIN_SALT_LEN || s.length > MAX_SALT_LEN) {
            alert('Salt must be between ' + MIN_SALT_LEN + ' and ' + MAX_SALT_LEN + ' characters');
            return;
        }
    }

    if (alg == 'argon2_copyparty') {
        if (usr === '') {
            alert('Please type your username.');
            return;
        }
    }


    const payload = { username: usr, password: pass, salt: s, algorithm: alg };
    const res = await fetch('/hash', {
        method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(payload)
    });

    if (!res.ok) {
        const txt = await res.text();
        alert('Error: ' + txt);
        return;
    }

    const data = await res.json();
    result.textContent = data.hash;
});

clearBtn.addEventListener('click', () => {
    password.value = '';
    salt.value = '';
    result.textContent = 'Result will appear here';
});

resultBtn.addEventListener('click', async  () => {
   if (!result.textContent || result.textContent === 'Result will appear here') {
      alert('Nothing to copy.');
   }

   try {
      await navigator.clipboard.writeText(result.textContent);
      alert('Copied to clipboard.');
   } catch (err) {
      alert('Failed to copy: ' + err);
   }
});