/**
 * AKSRT Conversation — 私信会话交互
 *
 * 从 page-messages.php 内联脚本提取而来。
 * 处理会话列表点击、消息加载、发送、已读标记。
 *
 * @package AKSRT
 */
(function () {
  'use strict';

  var wrap = document.getElementById('aksrt-pm-conversations');
  if (!wrap) return;

  var ajaxUrl = wrap.getAttribute('data-ajax');
  var nonce = wrap.getAttribute('data-nonce');
  var listView = wrap;
  var threadView = document.getElementById('aksrt-pm-thread');
  var messagesEl = document.getElementById('aksrt-pm-messages');
  var threadName = document.getElementById('aksrt-pm-thread-name');
  var input = document.getElementById('aksrt-pm-input');
  var sendBtn = document.getElementById('aksrt-pm-send');
  var backBtn = document.getElementById('aksrt-pm-back');
  var currentConv = 0;
  var currentOther = 0;

  function post(action, data) {
    var fd = new FormData();
    fd.append('action', action);
    fd.append('_nonce', nonce);
    if (data) {
      for (var key in data) {
        if (data.hasOwnProperty(key)) {
          fd.append(key, data[key]);
        }
      }
    }
    return fetch(ajaxUrl, { method: 'POST', body: fd, credentials: 'same-origin' })
      .then(function (r) { return r.json(); });
  }

  // Click conversation item → load thread
  document.addEventListener('click', function (e) {
    var item = e.target.closest('.aksrt-pm__item');
    if (!item) return;

    currentConv = parseInt(item.getAttribute('data-conv-id'));
    currentOther = parseInt(item.getAttribute('data-other-id'));

    var nm = item.querySelector('.aksrt-pm__name');
    if (nm) {
      threadName.textContent = nm.textContent.replace(/\d+$/, '').trim();
    }

    loadThread(currentConv, 1);
  });

  // Back button
  if (backBtn) {
    backBtn.addEventListener('click', function () {
      threadView.style.display = 'none';
      listView.style.display = '';
    });
  }

  // Send message
  if (sendBtn) {
    sendBtn.addEventListener('click', function () {
      var content = input.value.trim();
      if (!content || !currentConv) return;

      post('aksrt_pm_send', {
        conversation_id: currentConv,
        recipient_id: currentOther,
        content: content,
      }).then(function (d) {
        if (d.success) {
          input.value = '';
          loadThread(currentConv, 1);
        }
      });
    });
  }

  // Enter to send (Shift+Enter for newline)
  if (input) {
    input.addEventListener('keydown', function (e) {
      if (e.key === 'Enter' && !e.shiftKey) {
        e.preventDefault();
        sendBtn.click();
      }
    });
  }

  function loadThread(convId, page) {
    post('aksrt_pm_thread', {
      conversation_id: convId,
      page: page,
    }).then(function (d) {
      if (d.success && d.data) {
        renderMessages(d.data.messages || []);
        listView.style.display = 'none';
        threadView.style.display = '';

        // Mark as read
        post('aksrt_pm_mark_read', { conversation_id: convId });
      }
    });
  }

  function renderMessages(msgs) {
    messagesEl.innerHTML = '';
    msgs.forEach(function (m) {
      var div = document.createElement('div');
      div.className = 'aksrt-pm__msg' + (m.is_mine ? ' aksrt-pm__msg--mine' : '');
      div.innerHTML =
        '<div class="aksrt-pm__msg-bubble">' +
        '<div class="aksrt-pm__msg-content">' + (m.content || '').replace(/</g, '&lt;') + '</div>' +
        '<div class="aksrt-pm__msg-time">' + (m.created_at || '') + '</div>' +
        '</div>';
      messagesEl.appendChild(div);
    });
    messagesEl.scrollTop = messagesEl.scrollHeight;
  }
})();