(() => {
const pluginList = document.querySelector('#plugin-list');
const adminLabelList = document.querySelector('#admin-label-list');
const userList = document.querySelector('#user-list');
const userForm = document.querySelector('#user-form');
const adminControls = document.querySelector('#admin-controls');
const adminAuthNotice = document.querySelector('#admin-auth-notice');
const accessToken = localStorage.getItem('linklogAccessToken');

function authHeaders(includeJson = false) {
  return {
    ...(includeJson ? {'Content-Type': 'application/json'} : {}),
    ...(accessToken ? {Authorization: `Bearer ${accessToken}`} : {}),
  };
}

function renderPlugins(plugins) {
  pluginList.replaceChildren(...plugins.map((plugin) => {
    const row = document.createElement('div');
    row.className = 'plugin-row';

    const label = document.createElement('span');
    label.textContent = `${plugin.name} (${plugin.version})`;

    const button = document.createElement('button');
    button.type = 'button';
    button.textContent = plugin.enabled ? 'Disable' : 'Enable';
    button.addEventListener('click', () => updatePlugin(plugin, button));

    row.append(label, button);
    return row;
  }));
}

function renderLabels(labels) {
  adminLabelList.replaceChildren(...labels.map((label) => {
    const row = document.createElement('div');
    row.className = 'plugin-row';
    const text = document.createElement('span');
    text.textContent = `${label.name}${label.creator ? ` (${label.creator})` : ' (default)'}`;
    const button = document.createElement('button');
    button.type = 'button';
    button.className = 'danger-button';
    button.textContent = 'Delete';
    button.addEventListener('click', async () => {
      const response = await fetch(`/api/admin/labels/${label.id}`, {method: 'DELETE', headers: authHeaders()});
      if (response.ok) loadLabels();
    });
    row.append(text, button);
    return row;
  }));
}

async function loadLabels() {
  const response = await fetch('/api/admin/labels', {headers: authHeaders()});
  if (!response.ok) throw new Error('Could not load labels');
  renderLabels(await response.json());
}

function renderUsers(users) {
  userList.replaceChildren(...users.map((user) => {
    const row = document.createElement('div');
    row.className = 'plugin-row';
    const label = document.createElement('span');
    label.textContent = `${user.username} (${user.email})${user.is_admin ? ' - admin' : ''}`;
    const privilegeLabel = document.createElement('label');
    privilegeLabel.className = 'user-admin-toggle';
    const privilegeCheckbox = document.createElement('input');
    privilegeCheckbox.type = 'checkbox';
    privilegeCheckbox.checked = user.is_admin;
    privilegeCheckbox.setAttribute('aria-label', `Administrator rights for ${user.username}`);
    privilegeCheckbox.addEventListener('change', () => updateUserPrivilege(user, privilegeCheckbox));
    privilegeLabel.append(privilegeCheckbox, document.createTextNode(' Administrator'));
    const button = document.createElement('button');
    button.type = 'button';
    button.className = 'danger-button';
    button.textContent = 'Remove';
    button.addEventListener('click', () => removeUser(user, button));
    row.append(label, privilegeLabel, button);
    return row;
  }));
}

async function loadUsers() {
  const response = await fetch('/api/admin/users', {headers: authHeaders()});
  if (!response.ok) throw new Error('Could not load users');
  renderUsers(await response.json());
}

function showAdminState(isAdmin) {
  adminControls.classList.toggle('hidden', !isAdmin);
  adminAuthNotice.classList.toggle('hidden', isAdmin);
}

function showSignedOutState() {
  showAdminState(false);
  adminAuthNotice.innerHTML = 'Administrator sign-in required. <a href="/login">Sign in</a>';
}

function showUnauthorizedState() {
  showAdminState(false);
  adminAuthNotice.textContent = 'You are signed in, but you are not authorized to access this page.';
}

async function loadAdminState() {
  if (!accessToken) {
    showSignedOutState();
    return;
  }

  const sessionResponse = await fetch(`/api/auth/me?token=${encodeURIComponent(accessToken)}`);
  if (!sessionResponse.ok) {
    localStorage.removeItem('linklogAccessToken');
    showSignedOutState();
    return;
  }

  const user = await sessionResponse.json();
  if (!user.is_admin) {
    showUnauthorizedState();
    return;
  }

  await Promise.all([loadUsers(), loadPlugins(), loadLabels()]);
  showAdminState(true);
}

async function loadPlugins() {
  const response = await fetch('/api/admin/plugins', {headers: authHeaders()});
  if (!response.ok) throw new Error('Could not load plugins');
  renderPlugins(await response.json());
}

async function updatePlugin(plugin, button) {
  button.disabled = true;
  const response = await fetch(`/api/admin/plugins/${encodeURIComponent(plugin.name)}`, {
    method: 'PUT',
    headers: authHeaders(true),
    body: JSON.stringify({enabled: !plugin.enabled}),
  });
  if (response.ok) {
    await loadPlugins();
  } else {
    button.disabled = false;
  }
}

async function removeUser(user, button) {
  if (!window.confirm(`Remove ${user.username}?`)) return;
  button.disabled = true;
  const response = await fetch(`/api/admin/users/${encodeURIComponent(user.id)}`, {
    method: 'DELETE',
    headers: authHeaders(),
  });
  if (response.ok) {
    await loadUsers();
  } else {
    button.disabled = false;
  }
}

async function updateUserPrivilege(user, checkbox) {
  checkbox.disabled = true;
  const response = await fetch(`/api/admin/users/${encodeURIComponent(user.id)}`, {
    method: 'PUT',
    headers: authHeaders(true),
    body: JSON.stringify({is_admin: checkbox.checked}),
  });
  if (response.ok) {
    await loadUsers();
  } else {
    checkbox.checked = user.is_admin;
    checkbox.disabled = false;
  }
}

userForm.addEventListener('submit', async (event) => {
  event.preventDefault();
  const values = Object.fromEntries(new FormData(userForm));
  values.is_admin = userForm.elements.is_admin.checked;
  const response = await fetch('/api/admin/users', {
    method: 'POST',
    headers: authHeaders(true),
    body: JSON.stringify(values),
  });
  const status = document.querySelector('#user-status');
  status.textContent = response.ok ? 'User added.' : 'Could not add user.';
  status.style.color = response.ok ? '#94e2d5' : '#f38ba8';
  if (response.ok) {
    userForm.reset();
    await loadUsers();
  }
});

loadAdminState().catch((error) => {
  showAdminState(false);
  adminAuthNotice.textContent = accessToken
    ? `Could not verify administrator access: ${error.message}`
    : 'Administrator sign-in required.';
  adminAuthNotice.classList.remove('hidden');
  userList.textContent = '';
  pluginList.textContent = '';
  adminLabelList.textContent = '';
});
})();