import React, { useState, useEffect, useCallback, useRef } from 'react';
import { useNavigate } from 'react-router-dom';
import { LogIn, User, LogOut, ChevronDown, ShieldCheck, ShieldAlert } from '../icons/commonIcons';
import { Lightbulb } from '../icons/commonIcons';
import { authService, UserInfo } from '../services/authService';
import { BrandingContext } from '../App';

const Navbar: React.FC = () => {
  const navigate = useNavigate();
  const branding = React.useContext(BrandingContext);
  const [userInfo, setUserInfo] = useState<UserInfo | null>(null);
  const [isAuthenticated, setIsAuthenticated] = useState(false);
  const [, forceUpdate] = useState({});
  const [showDropdown, setShowDropdown] = useState(false);
  const dropdownRef = useRef<HTMLDivElement>(null);

  const checkAuthStatus = useCallback(() => {
    const authenticated = authService.isAuthenticated();
    const user = authService.getUserInfo();
    console.log('[Navbar] checkAuthStatus - authenticated:', authenticated, 'user:', user);
    setIsAuthenticated(authenticated);
    setUserInfo(authenticated ? user : null);
    forceUpdate({});
  }, []);

  useEffect(() => {
    // 初始检查
    checkAuthStatus();

    // 订阅认证状态变化
    const unsubscribe = authService.subscribe(() => {
      console.log('[Navbar] auth_state_change event received');
      checkAuthStatus();
    });

    // 监听存储变化（其他标签页）
    const handleStorageChange = (e: StorageEvent) => {
      if (e.key === 'aigc_space_token' || e.key === 'aigc_space_user_info' || e.key === null) {
        checkAuthStatus();
      }
    };

    window.addEventListener('storage', handleStorageChange);

    return () => {
      unsubscribe();
      window.removeEventListener('storage', handleStorageChange);
    };
  }, [checkAuthStatus]);

  const handleLogin = () => {
    navigate('/login');
  };

  const handleProfile = () => {
    setShowDropdown(false);
    navigate('/profile');
  };

  const handleLogout = async () => {
    setShowDropdown(false);

    // 先本地清理登录状态
    try {
      if (typeof window !== 'undefined') {
        localStorage.removeItem('aigc_space_token');
        localStorage.removeItem('aigc_space_refresh_token');
        localStorage.removeItem('aigc_space_user_info');
      }
    } catch (e) {
      // ignore
    }

    if (typeof window === 'undefined') return;

    // 查询后端 SSO 配置，决定跳转目标
    try {
      const cfg = await authService.getSsoConfig();
      if (cfg?.sso_enabled) {
        // SSO 启用：跳 CAS 注销页
        const casLogoutUrl = cfg.cas_login_url.replace(/\/login$/, '/logout');
        try {
          if (window.top && window.top !== window) {
            window.top.location.replace(casLogoutUrl);
          } else {
            window.location.replace(casLogoutUrl);
          }
        } catch {
          window.location.href = casLogoutUrl;
        }
      } else {
        // SSO 未启用：直接跳普通登录页
        window.location.replace('/');
      }
    } catch {
      window.location.replace('/');
    }
  };

  // 点击外部关闭下拉菜单
  useEffect(() => {
    const handleClickOutside = (event: MouseEvent) => {
      if (dropdownRef.current && !dropdownRef.current.contains(event.target as Node)) {
        setShowDropdown(false);
      }
    };

    document.addEventListener('mousedown', handleClickOutside);
    return () => document.removeEventListener('mousedown', handleClickOutside);
  }, []);

  return (
    <header className="fixed top-0 left-0 right-0 h-14 sm:h-16 bg-white border-b border-gray-100 flex items-center justify-between px-4 sm:px-6 z-50">
      {/* 左侧：标题 */}
      <div className="flex items-center space-x-2">
        <div className="w-7 h-7 sm:w-8 sm:h-8 bg-blue-600 rounded-lg flex items-center justify-center flex-shrink-0 overflow-hidden">
          {branding.system_logo
            ? <img src={branding.system_logo} alt="logo" className="w-full h-full object-contain" />
            : <Lightbulb className="text-white w-4 h-4 sm:w-5 sm:h-5" />}
        </div>
        <span className="text-base sm:text-xl font-bold text-blue-600 tracking-tight hidden xs:inline sm:inline">
          {branding.system_name}
        </span>
      </div>

      {/* 右侧：用户操作 */}
      <div className="flex items-center space-x-2 sm:space-x-4">
        {isAuthenticated ? (
          <>
            {/* 用户头像和昵称 - 下拉菜单 */}
            <div className="relative" ref={dropdownRef}>
              <div 
                onClick={() => setShowDropdown(!showDropdown)}
                className="flex items-center space-x-1 sm:space-x-2 cursor-pointer group hover:bg-gray-50 rounded-lg px-1 sm:px-2 py-1 transition-colors"
              >
                <div className="w-7 h-7 sm:w-8 sm:h-8 rounded-full overflow-hidden border border-gray-200 flex-shrink-0">
                  {userInfo?.avatar ? (
                    <img 
                      src={userInfo.avatar} 
                      alt="用户头像" 
                      className="w-full h-full object-cover"
                    />
                  ) : (
                    <div className="w-full h-full bg-gradient-to-br from-blue-400 to-blue-600 flex items-center justify-center text-white text-xs sm:text-sm font-bold">
                      {userInfo?.nickname?.charAt(0)?.toUpperCase() || 'U'}
                    </div>
                  )}
                </div>
                <div className="hidden sm:flex items-center">
                  <span className="text-sm font-medium text-gray-700 group-hover:text-blue-600 transition-colors">
                    {userInfo?.nickname || '用户'}
                  </span>
                  <ChevronDown className={`w-4 h-4 ml-1 text-gray-400 transition-transform ${showDropdown ? 'rotate-180' : ''}`} />
                </div>
                <ChevronDown className={`w-3 h-3 sm:hidden text-gray-400 transition-transform ${showDropdown ? 'rotate-180' : ''}`} />
              </div>
              
              {/* 下拉菜单 */}
              {showDropdown && (
                <div className="absolute right-0 top-full mt-2 w-40 bg-white rounded-lg shadow-lg border border-gray-100 py-1 z-50">
                  <button
                    onClick={handleProfile}
                    className="w-full flex items-center space-x-2 px-4 py-2 text-sm text-gray-700 hover:bg-gray-50 hover:text-blue-600 transition-colors"
                  >
                    <User className="w-4 h-4" />
                    <span>个人中心</span>
                  </button>
                  <button
                    onClick={handleLogout}
                    className="w-full flex items-center space-x-2 px-4 py-2 text-sm text-gray-700 hover:bg-gray-50 hover:text-red-600 transition-colors"
                  >
                    <LogOut className="w-4 h-4" />
                    <span>退出登录</span>
                  </button>
                </div>
              )}
            </div>
          </>
        ) : (
          /* 未登录状态 */
          <div className="flex items-center space-x-3">
            <button
              onClick={handleLogin}
              className="flex items-center space-x-1 sm:space-x-2 px-3 sm:px-4 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 transition-colors text-sm font-medium"
            >
              <LogIn className="w-4 h-4" />
              <span>登录</span>
            </button>
          </div>
        )}
      </div>
    </header>
  );
};

export default Navbar;