'use strict';

// ── Helpers ────────────────────────────────────────────────────────────────

function formatBytes(n) {
  if (!n) return 'unknown size';
  if (n < 1024) return n + ' B';
  if (n < 1024 ** 2) return (n / 1024).toFixed(1) + ' KB';
  if (n < 1024 ** 3) return (n / 1024 ** 2).toFixed(1) + ' MB';
  return (n / 1024 ** 3).toFixed(2) + ' GB';
}

function formatExpiry(isoStr) {
  return new Date(isoStr).toLocaleString();
}

function triggerDownload(blob, filename) {
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = filename || 'download';
  document.body.appendChild(a);
  a.click();
  a.remove();
  setTimeout(() => URL.revokeObjectURL(url), 10000);
}

// ── DOM refs ───────────────────────────────────────────────────────────────

const statusWrap  = document.getElementById('statusWrap');
const statusMsg   = document.getElementById('statusMsg');
const infoGrid    = document.getElementById('infoGrid');
const infoType    = document.getElementById('infoType');
const infoSize    = document.getElementById('infoSize');
const infoExpiry  = document.getElementById('infoExpiry');
const infoBurn    = document.getElementById('infoBurn');
const alertBox    = document.getElementById('alertBox');
const pwSection   = document.getElementById('pwSection');
const pwInput     = document.getElementById('pwInput');
const downloadBtn = document.getElementById('downloadBtn');
const textSection = document.getElementById('textSection');
const textOutput  = document.getElementById('textOutput');
const copyTextBtn = document.getElementById('copyTextBtn');

// ── Init ───────────────────────────────────────────────────────────────────

const shareId = location.pathname.split('/s/')[1];

(async function init() {
  if (!shareId) { showError('Invalid share URL.'); return; }

  let meta;
  try {
    const res = await fetch(`/api/share/${shareId}/meta`);
    if (!res.ok) {
      showError(res.status === 404
        ? 'This share does not exist or has expired.'
        : 'Failed to load share info.');
      return;
    }
    meta = await res.json();
  } catch {
    showError('Network error. Please check your connection.');
    return;
  }

  if (meta.locked) {
    showError(`Share locked — too many failed attempts. Try again in ${meta.lock_remaining}s.`);
    return;
  }

  // Show info grid
  statusWrap.classList.add('hidden');
  infoGrid.classList.remove('hidden');
  infoType.textContent   = meta.share_type === 'file'
    ? (meta.original_filename || 'File') : 'Text snippet';
  infoSize.textContent   = formatBytes(meta.filesize);
  infoExpiry.textContent = formatExpiry(meta.expires_at);
  infoBurn.textContent   = meta.burn_after_read ? 'Yes — deleted after this download' : 'No';

  if (meta.has_password) pwSection.classList.remove('hidden');
  downloadBtn.classList.remove('hidden');

  // Attach handlers now that we have meta
  downloadBtn.addEventListener('click', () => handleDownload(meta));
  pwInput.addEventListener('keydown', e => { if (e.key === 'Enter') handleDownload(meta); });
})();

// ── Download ───────────────────────────────────────────────────────────────

async function handleDownload(meta) {
  clearAlert();
  downloadBtn.disabled = true;
  downloadBtn.textContent = 'Downloading…';

  try {
    const res = await fetch(`/api/share/${shareId}/download`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ password: pwInput.value }),
    });

    if (res.status === 401) {
      const body = await res.json().catch(() => ({}));
      showAlert(body.detail || 'Incorrect password.');
      pwInput.value = '';
      pwInput.focus();
      return;
    }
    if (res.status === 429) {
      const body = await res.json().catch(() => ({}));
      showAlert(body.detail || 'Too many attempts. Please wait.');
      return;
    }
    if (!res.ok) {
      showAlert('Download failed. The share may have expired.');
      return;
    }

    if (meta.share_type === 'text') {
      const text = await res.text();
      textSection.classList.remove('hidden');
      textOutput.textContent = text;
      copyTextBtn.onclick = () => {
        navigator.clipboard.writeText(text);
        const orig = copyTextBtn.textContent;
        copyTextBtn.textContent = 'Copied!';
        setTimeout(() => (copyTextBtn.textContent = orig), 1500);
      };
      downloadBtn.textContent = 'Decrypted';
    } else {
      const blob = await res.blob();
      triggerDownload(blob, meta.original_filename);
      downloadBtn.textContent = 'Downloaded ✓';
    }

    if (meta.burn_after_read) {
      showAlert('This share has been deleted — it can no longer be accessed.', 'info');
    }

  } catch (err) {
    showAlert(err.message || 'An unexpected error occurred.');
  } finally {
    if (downloadBtn.textContent === 'Downloading…') {
      downloadBtn.disabled = false;
      downloadBtn.textContent = 'Decrypt & Download';
    }
  }
}

// ── UI helpers ─────────────────────────────────────────────────────────────

function showError(msg) {
  statusWrap.classList.remove('hidden');
  statusMsg.textContent = msg;
  statusMsg.className = 'alert alert-error';
  downloadBtn.classList.add('hidden');
}

function showAlert(msg, type = 'error') {
  alertBox.className = `alert alert-${type}`;
  alertBox.textContent = msg;
  alertBox.classList.remove('hidden');
  downloadBtn.disabled = false;
  downloadBtn.textContent = 'Decrypt & Download';
}

function clearAlert() { alertBox.classList.add('hidden'); }