/**
 * ChatbotSDK 入口文件
 * 单例模式，IIFE 挂载 window.ChatbotSDK
 *
 * 参数映射：
 *   integrateId → roleId（客服角色 ID）
 *   userId → accountId（客户账号 ID）
 *   chatId → 自动管理（从 /conversation/list 获取或自动生成）
 */
import { SDKConfig, ResolvedConfig, ChatbotSDKInstance } from './types';
import { parseConfig } from './config';
import { setDebug, logger } from './logger';
import { setApiConfig } from './api';
import { injectStyles, removeStyles } from './styles';
import { createLauncher, createChatWindow, enableDrag } from './dom';
import { initChat, initChatHistory, getMessages, setCategory, loadHistoryConversations } from './chat';
import { clearMessages } from './storage';
import { setLocale } from './i18n';

// ==================== 单例状态 ====================

let config: ResolvedConfig | null = null;
let isInitialized = false;
let launcherEl: HTMLElement | null = null;
let windowEl: HTMLElement | null = null;
let messagesContainer: HTMLElement | null = null;
let inputEl: HTMLTextAreaElement | null = null;
let sendBtn: HTMLElement | null = null;
let clearBtn: HTMLElement | null = null;
let categorySelect: HTMLSelectElement | null = null;
let historyPanel: HTMLElement | null = null;
let showLoadingFn: (() => HTMLElement) | null = null;
let hideLoadingFn: (() => void) | null = null;
let dragCleanup: (() => void) | null = null;

// ==================== 公开 API ====================

/** 初始化 SDK */
function init(rawConfig: SDKConfig): void {
  if (isInitialized) {
    logger.warn('SDK 已初始化，请先调用 destroy() 再重新初始化');
    return;
  }

  // 1. 配置解析与校验
  const parsed = parseConfig(rawConfig);
  if (!parsed) return;
  config = parsed;

  // 2. 设置国际化语言
  setLocale(config.locale);

  // 3. 设置日志级别
  setDebug(config.debug);

  // 4. 设置 API 配置
  setApiConfig(config);

  // 5. 注入样式
  injectStyles(config);

  // 6. 创建悬浮按钮
  launcherEl = createLauncher(config, toggle);
  document.body.appendChild(launcherEl);

  // 7. 创建聊天弹窗
  const dom = createChatWindow(config);
  windowEl = dom.window;
  messagesContainer = dom.messagesContainer;
  inputEl = dom.inputEl;
  sendBtn = dom.sendBtn;
  clearBtn = dom.clearBtn;
  categorySelect = dom.categorySelect;
  historyPanel = dom.historyPanel;
  showLoadingFn = dom.showLoading;
  hideLoadingFn = dom.hideLoading;
  document.body.appendChild(windowEl);

  // 8. 启用拖拽
  const headerEl = windowEl.querySelector('.csk-header') as HTMLElement;
  if (headerEl) {
    dragCleanup = enableDrag(headerEl, windowEl);
  }

  // 9. 初始化对话模块
  initChat(config, {
    messagesContainer,
    inputEl,
    sendBtn,
    clearBtn,
    categorySelect,
    historyPanel,
    showLoading: showLoadingFn,
    hideLoading: hideLoadingFn,
  });

  // 10. 监听知识库分类切换事件
  windowEl.addEventListener('csk:categoryChange', ((e: CustomEvent) => {
    setCategory(e.detail.categoryId);
  }) as EventListener);

  // 11. 监听会话管理面板加载事件
  windowEl.addEventListener('csk:loadHistory', () => {
    loadHistoryConversations();
  });

  isInitialized = true;
  logger.lifecycleInit(config.integrateId, config.requestDomain);

  // 12. 异步初始化 chatId 和对话历史（不阻塞 UI）
  initChatHistory().catch(err => {
    logger.warn('chatId 初始化失败，将在发送消息时重试', err);
  });
}

/** 销毁 SDK 实例 */
function destroy(): void {
  if (!isInitialized) return;

  if (launcherEl && launcherEl.parentNode) { launcherEl.parentNode.removeChild(launcherEl); launcherEl = null; }
  if (windowEl && windowEl.parentNode) { windowEl.parentNode.removeChild(windowEl); windowEl = null; }
  if (dragCleanup) { dragCleanup(); dragCleanup = null; }

  removeStyles();

  const oldIntegrateId = config?.integrateId;
  config = null;
  isInitialized = false;
  messagesContainer = null;
  inputEl = null;
  sendBtn = null;
  clearBtn = null;
  categorySelect = null;
  historyPanel = null;
  showLoadingFn = null;
  hideLoadingFn = null;

  logger.lifecycleDestroy(oldIntegrateId || '');
}

function open(): void {
  if (!windowEl) return;
  windowEl.classList.remove('csk-window--hidden');
}

function close(): void {
  if (!windowEl) return;
  windowEl.classList.add('csk-window--hidden');
}

function toggle(): void {
  if (!windowEl) return;
  if (windowEl.classList.contains('csk-window--hidden')) {
    open();
    setTimeout(() => { if (inputEl) inputEl.focus(); }, 100);
  } else {
    close();
  }
}

function clearHistory(): void {
  if (!config) return;
  if (clearBtn) { clearBtn.click(); }
  else if (confirm('确定清空所有对话记录？')) { clearMessages(config.integrateId); }
}

// ==================== 挂载到全局 ====================

const ChatbotSDK: ChatbotSDKInstance = {
  init,
  destroy,
  open,
  close,
  toggle,
  clearHistory,
};

if (typeof window !== 'undefined') {
  (window as unknown as Record<string, unknown>).ChatbotSDK = ChatbotSDK;
}

export default ChatbotSDK;