'use strict';

// ========== Token (sessionStorage — cleared on browser close) ==========

function _getToken() {
  return sessionStorage.getItem('baton_admin_token') || '';
}

function _saveToken(t) {
  sessionStorage.setItem('baton_admin_token', t);
}

function _clearToken() {
  sessionStorage.removeItem('baton_admin_token');
}

// ========== API wrapper ==========

async function _api(method, path, body) {
  const opts = {
    method,
    headers: { 'Authorization': 'Bearer ' + _getToken() },
  };
  if (body !== undefined) {
    opts.headers['Content-Type'] = 'application/json';
    opts.body = JSON.stringify(body);
  }

  const res = await fetch(path, opts);

  if (res.status === 204) return null;

  const text = await res.text().catch(() => '');
  if (!res.ok) {
    let detail = text;
    try { detail = JSON.parse(text).detail || text; } catch (_) {}
    throw new Error('HTTP ' + res.status + (detail ? ': ' + detail : ''));
  }

  try { return JSON.parse(text); } catch (_) { return null; }
}

// ========== UI helpers ==========

function _esc(str) {
  return String(str)
    .replace(/&/g, '&')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

function _setError(id, msg) {
  const el = document.getElementById(id);
  el.textContent = msg;
  el.hidden = !msg;
}

function _showPanel() {
  document.getElementById('screen-token').style.display = 'none';
  document.getElementById('screen-panel').classList.add('active');
}

function _showTokenScreen() {
  document.getElementById('screen-panel').classList.remove('active');
  document.getElementById('screen-token').style.display = '';
  document.getElementById('token-input').value = '';
}

// ========== Users table ==========

function _renderTable(users) {
  const tbody = document.getElementById('users-tbody');
  tbody.innerHTML = '';

  if (!users.length) {
    const tr = document.createElement('tr');
    tr.className = 'empty-row';
    tr.innerHTML = '<td colspan="6">Нет пользователей</td>';
    tbody.appendChild(tr);
    return;
  }

  users.forEach((u) => {
    const tr = document.createElement('tr');
    if (u.is_blocked) tr.classList.add('is-blocked');

    const date = u.created_at ? u.created_at.slice(0, 16).replace('T', ' ') : '—';
    const uuidShort = u.uuid ? u.uuid.slice(0, 8) + '…' : '—';

    tr.innerHTML = `
      <td class="col-id">${u.id}</td>
      <td>${_esc(u.name)}</td>
      <td class="col-uuid" title="${_esc(u.uuid)}">${_esc(uuidShort)}</td>
      <td>
        <span class="badge ${u.is_blocked ? 'badge--blocked' : 'badge--active'}">
          ${u.is_blocked ? 'Заблокирован' : 'Активен'}
        </span>
      </td>
      <td class="col-date">${_esc(date)}</td>
      <td class="col-actions">
        <button class="btn-sm"
          data-action="password"
          data-id="${u.id}"
          data-name="${_esc(u.name)}">Пароль</button>
        <button class="btn-sm ${u.is_blocked ? 'btn-sm--warn' : ''}"
          data-action="block"
          data-id="${u.id}"
          data-blocked="${u.is_blocked ? '1' : '0'}">
          ${u.is_blocked ? 'Разблокировать' : 'Заблокировать'}
        </button>
        <button class="btn-sm btn-sm--danger"
          data-action="delete"
          data-id="${u.id}"
          data-name="${_esc(u.name)}">Удалить</button>
      </td>
    `;
    tbody.appendChild(tr);
  });
}

// ========== Load users ==========

async function _loadUsers() {
  _setError('panel-error', '');
  try {
    const users = await _api('GET', '/admin/users');
    _renderTable(users);
  } catch (err) {
    _setError('panel-error', err.message);
  }
}

// ========== Login / Logout ==========

async function _handleLogin() {
  const input = document.getElementById('token-input');
  const btn = document.getElementById('btn-login');
  const token = input.value.trim();
  if (!token) return;

  btn.disabled = true;
  _setError('login-error', '');
  _saveToken(token);

  try {
    const users = await _api('GET', '/admin/users');
    _renderTable(users);
    _showPanel();
  } catch (err) {
    _clearToken();
    const msg = err.message.includes('401') ? 'Неверный токен' : err.message;
    _setError('login-error', msg);
    btn.disabled = false;
  }
}

function _handleLogout() {
  _clearToken();
  _showTokenScreen();
}

// ========== Table action dispatcher (event delegation) ==========

async function _handleTableClick(e) {
  const btn = e.target.closest('[data-action]');
  if (!btn) return;

  const { action, id, name, blocked } = btn.dataset;

  if (action === 'password') {
    _openPasswordModal(id, name);
  } else if (action === 'block') {
    await _toggleBlock(id, blocked === '1');
  } else if (action === 'delete') {
    await _handleDelete(id, name);
  }
}

// ========== Block / Unblock ==========

async function _toggleBlock(userId, currentlyBlocked) {
  _setError('panel-error', '');
  try {
    await _api('PUT', `/admin/users/${userId}/block`, { is_blocked: !currentlyBlocked });
    await _loadUsers();
  } catch (err) {
    _setError('panel-error', err.message);
  }
}

// ========== Delete ==========

async function _handleDelete(userId, userName) {
  if (!confirm(`Удалить пользователя "${userName}"?\n\nБудут удалены все его сигналы. Действие нельзя отменить.`)) return;
  _setError('panel-error', '');
  try {
    await _api('DELETE', `/admin/users/${userId}`);
    await _loadUsers();
  } catch (err) {
    _setError('panel-error', err.message);
  }
}

// ========== Password modal ==========

function _openPasswordModal(userId, userName) {
  document.getElementById('modal-pw-subtitle').textContent = `Пользователь: ${userName}`;
  document.getElementById('modal-pw-user-id').value = userId;
  document.getElementById('new-password').value = '';
  _setError('modal-pw-error', '');
  document.getElementById('btn-pw-save').disabled = false;
  document.getElementById('modal-password').hidden = false;
  document.getElementById('new-password').focus();
}

function _closePasswordModal() {
  document.getElementById('modal-password').hidden = true;
}

async function _handleSetPassword() {
  const userId = document.getElementById('modal-pw-user-id').value;
  const password = document.getElementById('new-password').value;
  const btn = document.getElementById('btn-pw-save');

  if (!password) {
    _setError('modal-pw-error', 'Введите пароль');
    return;
  }

  btn.disabled = true;
  _setError('modal-pw-error', '');

  try {
    await _api('PUT', `/admin/users/${userId}/password`, { password });
    _closePasswordModal();
  } catch (err) {
    _setError('modal-pw-error', err.message);
    btn.disabled = false;
  }
}

// ========== Create user modal ==========

function _openCreateModal() {
  document.getElementById('create-uuid').value = crypto.randomUUID();
  document.getElementById('create-name').value = '';
  document.getElementById('create-password').value = '';
  _setError('create-error', '');
  document.getElementById('btn-create-submit').disabled = false;
  document.getElementById('modal-create').hidden = false;
  document.getElementById('create-name').focus();
}

function _closeCreateModal() {
  document.getElementById('modal-create').hidden = true;
}

async function _handleCreateUser() {
  const uuid = document.getElementById('create-uuid').value.trim();
  const name = document.getElementById('create-name').value.trim();
  const password = document.getElementById('create-password').value;
  const btn = document.getElementById('btn-create-submit');

  if (!uuid || !name) {
    _setError('create-error', 'UUID и имя обязательны');
    return;
  }

  btn.disabled = true;
  _setError('create-error', '');

  const body = { uuid, name };
  if (password) body.password = password;

  try {
    await _api('POST', '/admin/users', body);
    _closeCreateModal();
    await _loadUsers();
  } catch (err) {
    const msg = err.message.includes('409') ? 'Пользователь с таким UUID уже существует' : err.message;
    _setError('create-error', msg);
    btn.disabled = false;
  }
}

// ========== Init ==========

function _init() {
  // Login screen
  document.getElementById('btn-login').addEventListener('click', _handleLogin);
  document.getElementById('token-input').addEventListener('keydown', (e) => {
    if (e.key === 'Enter') _handleLogin();
  });

  // Panel
  document.getElementById('btn-logout').addEventListener('click', _handleLogout);
  document.getElementById('btn-create').addEventListener('click', _openCreateModal);

  // Table (event delegation)
  document.getElementById('users-table').addEventListener('click', _handleTableClick);

  // Password modal
  document.getElementById('btn-pw-cancel').addEventListener('click', _closePasswordModal);
  document.getElementById('btn-pw-save').addEventListener('click', _handleSetPassword);
  document.getElementById('new-password').addEventListener('keydown', (e) => {
    if (e.key === 'Enter') _handleSetPassword();
  });
  document.getElementById('modal-password').addEventListener('click', (e) => {
    if (e.target.id === 'modal-password') _closePasswordModal();
  });

  // Create modal
  document.getElementById('btn-create-cancel').addEventListener('click', _closeCreateModal);
  document.getElementById('btn-create-submit').addEventListener('click', _handleCreateUser);
  document.getElementById('create-password').addEventListener('keydown', (e) => {
    if (e.key === 'Enter') _handleCreateUser();
  });
  document.getElementById('modal-create').addEventListener('click', (e) => {
    if (e.target.id === 'modal-create') _closeCreateModal();
  });

  // Auto-login if token is already saved in sessionStorage
  if (_getToken()) {
    _showPanel();
    _loadUsers().catch(() => {
      _clearToken();
      _showTokenScreen();
    });
  }
}

document.addEventListener('DOMContentLoaded', _init);