// User Management admin page: create users, change passwords, delete users.
// CSRF token and the current user's id are handed off from PHP via
// <body data-csrf-token="..." data-current-user-id="...">.

const csrfToken = document.body.dataset.csrfToken;
const currentUserId = document.body.dataset.currentUserId;

const userModal = document.getElementById('modal-user-backdrop');
const passwordModal = document.getElementById('modal-password-backdrop');

function escapeHtml(text) {
  const div = document.createElement('div');
  div.textContent = text ?? '';
  return div.innerHTML;
}

async function postForm(formData) {
  const response = await fetch('users.php', {
    method: 'POST',
    body: formData,
    headers: { 'X-Requested-With': 'XMLHttpRequest' }
  });
  return response.json();
}

const EYE_OPEN_SVG = `
  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round" class="icon-eye">
    <path d="M2 12s3-7 10-7 10 7 10 7-3 7-10 7-10-7-10-7Z" />
    <circle cx="12" cy="12" r="3" />
  </svg>
`;

const EYE_OFF_SVG = `
  <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.8" stroke-linecap="round" stroke-linejoin="round" class="icon-eye-off">
    <path d="M9.88 9.88a3 3 0 1 0 4.24 4.24" />
    <path d="M10.73 5.08A10.43 10.43 0 0 1 12 5c7 0 10 7 10 7a13.16 13.16 0 0 1-1.67 2.68" />
    <path d="M6.61 6.61A13.526 13.526 0 0 0 2 12s3 7 10 7a9.74 9.74 0 0 0 5.39-1.61" />
    <line x1="2" y1="2" x2="22" y2="22" />
  </svg>
`;

function resetPasswordVisibility(form) {
  form.querySelectorAll('.password-toggle-btn').forEach((btn) => {
    const input = document.getElementById(btn.dataset.target);
    if (input) input.type = 'password';
    btn.setAttribute('aria-label', 'Show password');
    btn.innerHTML = EYE_OPEN_SVG;
  });
}

// Add User modal
function openUserModal() {
  const form = document.getElementById('form-user');
  form.reset();
  resetPasswordVisibility(form);
  userModal.classList.add('is-open');
  document.getElementById('user-field-username').focus();
}

function closeUserModal() {
  userModal.classList.remove('is-open');
}

// Change Password modal
function openPasswordModal(userId, username) {
  const isSelf = String(userId) === currentUserId;
  const form = document.getElementById('form-password');

  form.reset();
  resetPasswordVisibility(form);
  document.getElementById('password-field-user-id').value = userId;
  document.getElementById('modal-password-title').textContent = isSelf
    ? '🔑 Change Your Password'
    : `🔑 Change Password for ${username}`;

  document.getElementById('password-current-group').style.display = isSelf ? '' : 'none';

  passwordModal.classList.add('is-open');
  (isSelf ? document.getElementById('password-field-current') : document.getElementById('password-field-new')).focus();
}

function closePasswordModal() {
  passwordModal.classList.remove('is-open');
}

document.getElementById('btn-new-user').addEventListener('click', () => openUserModal());
document.getElementById('btn-close-user-modal').addEventListener('click', closeUserModal);
document.getElementById('btn-cancel-user').addEventListener('click', closeUserModal);
document.getElementById('btn-close-password-modal').addEventListener('click', closePasswordModal);
document.getElementById('btn-cancel-password').addEventListener('click', closePasswordModal);

// Password visibility toggles (works inside both modals)
document.addEventListener('click', (e) => {
  const toggleBtn = e.target.closest('.password-toggle-btn');
  if (!toggleBtn) return;

  const targetId = toggleBtn.dataset.target;
  const input = document.getElementById(targetId);
  if (!input) return;

  const isPassword = input.type === 'password';
  input.type = isPassword ? 'text' : 'password';

  toggleBtn.setAttribute('aria-label', isPassword ? 'Hide password' : 'Show password');
  toggleBtn.innerHTML = isPassword ? EYE_OFF_SVG : EYE_OPEN_SVG;
  input.focus();
});

// Create user
document.getElementById('form-user').addEventListener('submit', async (e) => {
  e.preventDefault();
  const saveBtn = document.getElementById('btn-save-user');
  saveBtn.disabled = true;
  saveBtn.textContent = 'Saving...';

  try {
    const res = await postForm(new FormData(e.target));
    if (res.success) {
      closeUserModal();
      insertUserRow(res.user);
    } else {
      alert(res.error || 'Failed to create user.');
    }
  } catch {
    alert('Network error. Please try again.');
  } finally {
    saveBtn.disabled = false;
    saveBtn.textContent = 'Create User';
  }
});

// Change password
document.getElementById('form-password').addEventListener('submit', async (e) => {
  e.preventDefault();
  const saveBtn = document.getElementById('btn-save-password');
  saveBtn.disabled = true;
  saveBtn.textContent = 'Saving...';

  try {
    const res = await postForm(new FormData(e.target));
    if (res.success) {
      closePasswordModal();
      alert('Password updated.');
    } else {
      alert(res.error || 'Failed to update password.');
    }
  } catch {
    alert('Network error. Please try again.');
  } finally {
    saveBtn.disabled = false;
    saveBtn.textContent = 'Update Password';
  }
});

// Delegate table actions: Change Password, Delete
document.getElementById('users-tbody').addEventListener('click', async (e) => {
  const { target } = e;

  if (target.classList.contains('btn-change-password')) {
    openPasswordModal(target.dataset.id, target.dataset.username);
    return;
  }

  if (target.classList.contains('btn-delete-user')) {
    if (!confirm('Are you sure you want to delete this user? This cannot be undone.')) return;
    const row = target.closest('tr');

    const fd = new FormData();
    fd.append('action', 'delete_user');
    fd.append('user_id', target.dataset.id);
    fd.append('csrf_token', csrfToken);

    try {
      const data = await postForm(fd);
      if (data.success && row) {
        row.style.transition = 'opacity 0.2s ease, transform 0.2s ease';
        row.style.opacity = '0';
        row.style.transform = 'translateX(-10px)';
        setTimeout(() => row.remove(), 200);
      } else if (!data.success) {
        alert(data.error || 'Failed to delete user.');
      }
    } catch {
      alert('Network error. Please try again.');
    }
  }
});

function insertUserRow(user) {
  const tbody = document.getElementById('users-tbody');

  const tr = document.createElement('tr');
  tr.id = `user-row-${user.id}`;
  tr.dataset.userId = user.id;

  // data-username is set via dataset below, never interpolated into the
  // HTML string — escapeHtml() only escapes for text-content positions,
  // not attribute values, so it can't safely build an attribute string.
  tr.innerHTML = `
    <td data-label="Username"><strong>${escapeHtml(user.username)}</strong></td>
    <td data-label="Role">${escapeHtml(user.role.charAt(0).toUpperCase() + user.role.slice(1))}</td>
    <td class="font-mono item-sort-cell" data-label="Created">${escapeHtml(user.created_at)}</td>
    <td data-label="Actions"><div class="admin-table-actions">
      <button type="button" class="btn btn-outline btn-sm btn-change-password" data-id="${user.id}">Change Password</button>
      <button type="button" class="btn btn-danger btn-sm btn-delete-user" data-id="${user.id}">Delete</button>
    </div></td>
  `;
  tr.querySelector('.btn-change-password').dataset.username = user.username;

  tbody.appendChild(tr);
}