script.js

const copyButtonElement = document.getElementById('copy-button');
const correctInfoElement = document.getElementById('is-corrected');
const resultWrapperElement = document.querySelector('.result-wrapper');
const correcterInput = document.getElementById('correcter');
const timecodesTextarea = document.getElementById('timecodes');
const resultElement = document.getElementById('result');
const signToggle = document.getElementById('sign-toggle');

let debounceTimer = null;
let isNegative = false;

// --- Pure logic ---

function parseTimecode(str) {
  const parts = str.split(':').map(Number);
  if (parts.length === 2) {
    return { hours: 0, minutes: parts[0], seconds: parts[1] };
  }
  if (parts.length === 3) {
    return { hours: parts[0], minutes: parts[1], seconds: parts[2] };
  }
  return null;
}

function toSeconds(tc) {
  return tc.hours * 3600 + tc.minutes * 60 + tc.seconds;
}

function formatTimecode(tc) {
  return `${pad(tc.hours)}:${pad(tc.minutes)}:${pad(tc.seconds)}`;
}

function pad(n) {
  return String(n).padStart(2, '0');
}

function correctTimecodes(difference, input, subtract) {
  const diffTc = parseTimecode(difference);
  if (!diffTc) {
    return { error: t('invalidDiff') };
  }
  const diffSec = toSeconds(diffTc);

  const lines = input.split('\n');
  const result = [];

  for (const line of lines) {
    if (!line.trim()) {
      result.push(line);
      continue;
    }

    const match = line.match(/\d{1,2}:\d{2}(?::\d{2})?/);
    if (!match) {
      result.push(line);
      continue;
    }

    const tc = parseTimecode(match[0]);
    if (!tc) {
      result.push(line);
      continue;
    }

    const totalSec = subtract
      ? toSeconds(tc) - diffSec
      : toSeconds(tc) + diffSec;

    if (totalSec < 0) {
      result.push(line);
      continue;
    }

    const corrected = {
      hours: Math.floor(totalSec / 3600),
      minutes: Math.floor((totalSec % 3600) / 60),
      seconds: totalSec % 60,
    };

    result.push(line.replace(match[0], formatTimecode(corrected)));
  }

  return { value: result.join('\n') };
}

// --- UI ---

function setStatus(text, color) {
  correctInfoElement.textContent = text;
  correctInfoElement.style.color = color;
}

function updateUI() {
  const hasInput = correcterInput.value.length > 0;
  const hasTextarea = timecodesTextarea.value.length > 0;
  const ready = hasInput && hasTextarea;

  copyButtonElement.classList.toggle('show-button', ready);
  resultWrapperElement.classList.toggle('ready', ready);
  document.body.classList.toggle('ready', ready);

  // Update result placeholder text for current language
  resultElement.style.setProperty('--placeholder', `"${t('resultPlaceholder')}"`);

  if (ready) {
    const out = correctTimecodes(correcterInput.value, timecodesTextarea.value, isNegative);
    if (out.error) {
      setStatus(out.error, 'red');
      resultElement.innerText = '';
    } else {
      resultElement.innerText = out.value;
      setStatus(t('success'), 'green');
    }
  } else {
    correctInfoElement.textContent = '';
    correctInfoElement.style.color = '';
  }
}

function toggleSign() {
  isNegative = !isNegative;
  signToggle.textContent = isNegative ? '-' : '+';
  signToggle.classList.toggle('negative', isNegative);
  updateUI();
}

function debouncedUpdate() {
  clearTimeout(debounceTimer);
  debounceTimer = setTimeout(updateUI, 150);
}

function copyResult() {
  const text = resultElement.innerText;
  if (!text) return;

  navigator.clipboard.writeText(text).then(() => {
    copyButtonElement.textContent = t('copied');
    setTimeout(() => {
      copyButtonElement.textContent = t('copyButton');
    }, 2000);
  });
}

function setValue(type) {
  if (type === 'input') {
    correcterInput.value = document.getElementById('example-correcter').textContent;
  } else {
    timecodesTextarea.value = document.getElementById('example-list').innerText;
  }
  updateUI();
}

function showCopiedToast() {
  const existing = document.querySelector('.copied-toast');
  if (existing) existing.remove();

  const toast = document.createElement('div');
  toast.className = 'copied-toast';
  toast.textContent = t('copied');
  resultElement.appendChild(toast);

  requestAnimationFrame(() => toast.classList.add('visible'));

  setTimeout(() => {
    toast.classList.remove('visible');
    setTimeout(() => toast.remove(), 300);
  }, 1500);
}

// --- Events ---

correcterInput.addEventListener('input', debouncedUpdate);
timecodesTextarea.addEventListener('input', debouncedUpdate);

resultElement.addEventListener('click', () => {
  const text = resultElement.innerText;
  if (!text) return;

  navigator.clipboard.writeText(text).then(() => {
    showCopiedToast();
  });
});

// --- Init ---

applyLang();