/**
 * Backups page — lists backup archives with size/date, and wires up
 * create/restore/delete operations via native host messages.
 * Depends on: core/utils.js ($, escapeHtml, timeAgo),
 *             ui/toast.js (showToast), ui/modal.js (openModal, closeModal, showModalError)
 */

let pendingRestoreFilename = null;
let pendingDeleteFilename = null;

function formatBytes(bytes) {
  if (bytes < 1024) return bytes + ' B';
  if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(1) + ' KB';
  return (bytes / (1024 * 1024)).toFixed(2) + ' MB';
}

/**
 * Re-render the backups table with the provided list of backup entries.
 * @param {Array<{filename: string, size: number, createdAt: number}>} backups
 */
function updateBackupsTable(backups) {
  const tbody = $('backupsTable');
  if (!tbody) return;
  const countEl = $('backupCount');
  if (countEl) countEl.textContent = backups ? backups.length : 0;
  if (!backups || backups.length === 0) {
    tbody.innerHTML = `<tr><td colspan="4"><div class="empty-state">
      <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5" style="width:32px;height:32px;color:var(--text4)"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="17,8 12,3 7,8"/><line x1="12" y1="3" x2="12" y2="15"/></svg>
      <div class="empty-state-title">No backups yet</div>
      <div class="empty-state-desc">Click "Take Backup" to create your first backup</div>
    </div></td></tr>`;
    return;
  }
  tbody.innerHTML = backups.map((b) => {
    const name = escapeHtml(b.filename);
    const created = b.createdAt ? timeAgo(b.createdAt) : '—';
    const size = b.size ? formatBytes(b.size) : '—';
    return `<tr>
      <td><span class="mono" style="font-size:12px;">${name}</span></td>
      <td>${created}</td>
      <td>${size}</td>
      <td>
        <div style="display:flex;gap:6px;">
          <button class="btn btn-secondary btn-sm" data-backup-restore="${escapeHtml(b.filename)}">Restore</button>
          <button class="btn btn-danger btn-sm" data-backup-delete="${escapeHtml(b.filename)}">Delete</button>
        </div>
      </td>
    </tr>`;
  }).join('');
}

/**
 * Fetch the current backup list from the native host and re-render the table.
 */
function refreshBackups() {
  chrome.runtime.sendMessage(
    { target: 'holesail-native', action: 'send', payload: { type: 'listBackups' } },
    (response) => {
      if (chrome.runtime.lastError) return;
      if (response && response.ok) {
        updateBackupsTable(response.backups || []);
      }
    }
  );
}

/**
 * Attach all event listeners for the Backups page.
 * Called once during dashboard initialisation.
 */
function setupBackupEvents() {
  $('btnTakeBackup')?.addEventListener('click', () => {
    const btn = $('btnTakeBackup');
    if (btn) { btn.disabled = true; btn.textContent = 'Creating…'; }
    chrome.runtime.sendMessage(
      { target: 'holesail-native', action: 'send', payload: { type: 'createBackup' } },
      (response) => {
        if (btn) {
          btn.disabled = false;
          btn.innerHTML = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2"><path d="M21 15v4a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2v-4"/><polyline points="17,8 12,3 7,8"/><line x1="12" y1="3" x2="12" y2="15"/></svg> Take Backup`;
        }
        if (response && response.ok) {
          showToast('Backup created: ' + response.filename, 'success');
          refreshBackups();
        } else {
          showToast(response?.error || 'Backup failed', 'error');
        }
      }
    );
  });

  $('backupsTable')?.addEventListener('click', (e) => {
    const restoreBtn = e.target.closest('[data-backup-restore]');
    if (restoreBtn) {
      pendingRestoreFilename = restoreBtn.dataset.backupRestore;
      const nameEl = $('restoreBackupName');
      if (nameEl) nameEl.textContent = pendingRestoreFilename;
      openModal('modal-restoreBackup');
      return;
    }
    const deleteBtn = e.target.closest('[data-backup-delete]');
    if (deleteBtn) {
      pendingDeleteFilename = deleteBtn.dataset.backupDelete;
      const nameEl = $('deleteBackupName');
      if (nameEl) nameEl.textContent = pendingDeleteFilename;
      openModal('modal-deleteBackup');
    }
  });

  $('restoreBackupConfirm')?.addEventListener('click', () => {
    if (!pendingRestoreFilename) return;
    const btn = $('restoreBackupConfirm');
    if (btn) btn.disabled = true;
    chrome.runtime.sendMessage(
      { target: 'holesail-native', action: 'send', payload: { type: 'restoreBackup', payload: { filename: pendingRestoreFilename } } },
      (response) => {
        if (btn) btn.disabled = false;
        if (response && response.ok) {
          closeModal('modal-restoreBackup');
          const certsNote = response.restoredCerts ? ' Certificates restored.' : '';
          showToast('Backup restored.' + certsNote + ' Restart tunnels to apply changes.', 'success');
          pendingRestoreFilename = null;
          refresh();
        } else {
          showModalError('modal-restoreBackup', 'restoreBackupError', response?.error || 'Restore failed');
        }
      }
    );
  });

  $('deleteBackupConfirm')?.addEventListener('click', () => {
    if (!pendingDeleteFilename) return;
    const btn = $('deleteBackupConfirm');
    if (btn) btn.disabled = true;
    chrome.runtime.sendMessage(
      { target: 'holesail-native', action: 'send', payload: { type: 'deleteBackup', payload: { filename: pendingDeleteFilename } } },
      (response) => {
        if (btn) btn.disabled = false;
        if (response && response.ok) {
          closeModal('modal-deleteBackup');
          showToast('Backup deleted', 'success');
          pendingDeleteFilename = null;
          refreshBackups();
        } else {
          showModalError('modal-deleteBackup', 'deleteBackupError', response?.error || 'Delete failed');
        }
      }
    );
  });
}