const apiFetch = async (url, options = {}) => {
  const opts = {
    headers: { 'Content-Type': 'application/json' },
    ...options,
  };
  if (opts.body && typeof opts.body !== 'string') {
    opts.body = JSON.stringify(opts.body);
  }
  const res = await fetch(url, opts);
  if (!res.ok) {
    throw new Error(`API error: ${res.status}`);
  }
  return res.json();
};

const showToast = (message, type = 'success') => {
  const container = document.querySelector('.toast-container');
  if (!container) return;
  const toast = document.createElement('div');
  toast.className = `toast align-items-center text-bg-${type} border-0 show`;
  toast.setAttribute('role', 'alert');
  toast.innerHTML = `
    <div class="d-flex">
      <div class="toast-body">${message}</div>
      <button type="button" class="btn-close btn-close-white me-2 m-auto" data-bs-dismiss="toast"></button>
    </div>`;
  container.appendChild(toast);
  setTimeout(() => toast.remove(), 3200);
};

const formatTime = (value) => {
  if (!value) return '';
  const d = new Date(value);
  if (Number.isNaN(d.getTime())) return value;
  return d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
};

const initAgent = () => {
  const listEl = document.querySelector('[data-contacts]');
  const chatTitle = document.querySelector('[data-chat-title]');
  const chatBody = document.querySelector('[data-chat-body]');
  const form = document.querySelector('[data-chat-form]');
  const input = document.querySelector('[data-chat-input]');
  const emojiTrigger = document.querySelector('[data-emoji-trigger]');
  const emojiPicker = document.querySelector('[data-emoji-picker]');
  const shortcutList = document.getElementById('shortcutList');
  const newShortcutInput = document.getElementById('newShortcut');
  const addShortcutBtn = document.getElementById('addShortcut');
  const shortcutContainer = document.querySelector('[data-shortcuts]');

  let contacts = [];
  let activeId = null;
  let shortcuts = JSON.parse(localStorage.getItem('shortcuts') || '["你好", "请问有什么可以帮您？", "谢谢"]');

  // Country selector
  const countryList = document.getElementById('countryList');
  const countrySearch = document.getElementById('countrySearch');
  const selectedCode = document.getElementById('selectedCode');
  const phoneInput = document.getElementById('phoneNumber');

  const renderCountryList = (filter = '') => {
      countryList.innerHTML = '';
      countries.filter(c => c.name.includes(filter) || c.code.includes(filter)).forEach(c => {
          const item = document.createElement('div');
          item.className = 'country-item';
          item.textContent = `${c.name} (${c.code})`;
          item.onclick = () => {
              selectedCode.textContent = c.code;
              countrySearch.value = c.name;
              renderCountryList();
          };
          countryList.appendChild(item);
      });
  };

  countrySearch.addEventListener('input', e => renderCountryList(e.target.value));
  renderCountryList();

  document.getElementById('startChat').onclick = async () => {
      const phone = selectedCode.textContent + phoneInput.value;
      if (!phoneInput.value) return;
      
      try {
          // Send to API to create/get contact
          const res = await apiFetch('/api/contacts.php', { method: 'POST', body: { phone } });
          const newContact = res.contact;
          contacts.unshift(newContact);
          renderContacts();
          setActive(newContact.id);
          bootstrap.Modal.getInstance(document.getElementById('countryModal')).hide();
      } catch (err) {
          showToast('无法启动聊天', 'danger');
      }
  };

  const renderShortcuts = () => {
    shortcutContainer.innerHTML = shortcuts.map(s => 
        `<button class="btn btn-sm btn-outline-info me-1" onclick="document.querySelector('[data-chat-input]').value += '${s}'">${s}</button>`
    ).join('');
    
    shortcutList.innerHTML = shortcuts.map((s, i) => `
        <li class="list-group-item d-flex justify-content-between">
            ${s} <button class="btn btn-sm btn-danger" onclick="removeShortcut(${i})">删除</button>
        </li>
    `).join('');
  };

  window.removeShortcut = (i) => {
      shortcuts.splice(i, 1);
      localStorage.setItem('shortcuts', JSON.stringify(shortcuts));
      renderShortcuts();
  };

  addShortcutBtn.addEventListener('click', () => {
      if(newShortcutInput.value) {
          shortcuts.push(newShortcutInput.value);
          localStorage.setItem('shortcuts', JSON.stringify(shortcuts));
          newShortcutInput.value = '';
          renderShortcuts();
      }
  });

  emojiTrigger.addEventListener('click', () => emojiPicker.classList.toggle('d-none'));
  emojiPicker.addEventListener('emoji-click', e => {
      input.value += e.detail.unicode;
      emojiPicker.classList.add('d-none');
  });

  const renderContacts = () => {
    listEl.innerHTML = '';
    contacts.forEach((contact) => {
      const item = document.createElement('div');
      item.className = `contact-item ${contact.id === activeId ? 'active' : ''}`;
      item.style.padding = '10px';
      item.style.borderBottom = '1px solid #eee';
      item.style.cursor = 'pointer';
      item.innerHTML = `
        <div>
          <div class="fw-semibold">${contact.phone}</div>
          <div class="meta text-truncate" style="font-size: 0.8em; color: #666;">${contact.last_message || '暂无消息'}</div>
        </div>
      `;
      item.addEventListener('click', () => setActive(contact.id));
      listEl.appendChild(item);
    });
  };

  const renderMessages = (messages) => {
    chatBody.innerHTML = '';
    messages.forEach((msg) => {
      const item = document.createElement('div');
      item.className = `message ${msg.direction === 'out' ? 'out' : 'in'}`;
      item.innerHTML = `<div>${msg.body}</div><div class="time">${formatTime(msg.created_at)}</div>`;
      chatBody.appendChild(item);
    });
    chatBody.scrollTop = chatBody.scrollHeight;
  };

  const loadContacts = async () => {
    const data = await apiFetch('/api/contacts.php');
    contacts = data.contacts || [];
    renderContacts();
  };

  const loadMessages = async () => {
    if (!activeId) return;
    const data = await apiFetch(`/api/messages.php?contact_id=${activeId}`);
    renderMessages(data.messages || []);
  };

  const setActive = async (id) => {
    activeId = id;
    const contact = contacts.find(c => c.id === id);
    chatTitle.textContent = contact ? contact.phone : '未知联系人';
    renderContacts();
    await loadMessages();
  };

  form?.addEventListener('submit', async (e) => {
    e.preventDefault();
    if (!activeId) return;
    const body = input.value.trim();
    if (!body) return;
    await apiFetch('/api/messages.php', { method: 'POST', body: { contact_id: activeId, body } });
    input.value = '';
    await loadMessages();
  });

  renderShortcuts();
  loadContacts();
  setInterval(loadContacts, 3000);
};

document.addEventListener('DOMContentLoaded', () => {
  if (document.body.dataset.page === 'agent') initAgent();
});