import { Link, useMatches } from '@remix-run/react';

interface BreadcrumbItem {
  title: string;
  to?: string;
}

interface BreadcrumbProps {
  items?: BreadcrumbItem[];
  className?: string;
}

interface PreviousRouteData {
  title: string;
  to: string;
}

interface Handle {
  breadcrumb: string | ((data: unknown) => string);
  to?: string;  // 自定义面包屑链接
  previousRoute?: PreviousRouteData | ((data: unknown) => PreviousRouteData | undefined);
  breadcrumbClassName?: string;
}

interface Match {
  handle?: Handle;
  pathname: string;
  data: unknown;
}

export function Breadcrumb({ items = [], className = '' }: BreadcrumbProps) {
  const matches = useMatches() as Match[];
  
  // 构建面包屑数据
  const breadcrumbs = items.length > 0 ? items : matches
    .filter(match => match.handle?.breadcrumb)
    .map((match, index, array) => {
      // 当前路由的面包屑
      const current = {
        title: typeof match.handle?.breadcrumb === 'function'
          ? match.handle.breadcrumb(match.data)
          : match.handle?.breadcrumb as string,
        to: match.handle?.to || match.pathname  // 优先使用 handle.to，否则使用 pathname
      };
      
      // 如果当前路由有previousRoute属性且该路由是数组中的最后一个
      if (match.handle?.previousRoute && index === array.length - 1) {
        // 获取previousRoute数据，支持函数形式
        const prevRouteData = typeof match.handle.previousRoute === 'function'
          ? match.handle.previousRoute(match.data)
          : match.handle.previousRoute;
        
        // 如果previousRoute存在，添加到面包屑中
        if (prevRouteData) {
          return [
            {
              title: prevRouteData.title,
              to: prevRouteData.to
            },
            current
          ];
        }
      }
      
      return [current];
    })
    .flat(); // 扁平化数组

  // 获取自定义类名
  const getCustomClassName = () => {
    const lastMatch = matches[matches.length - 1];
    return lastMatch?.handle?.breadcrumbClassName || '';
  };

  if (breadcrumbs.length === 0) {
    return null;
  }

  // 应用自定义类名
  const customClassName = getCustomClassName();
  const finalClassName = `mb-4 ${className} ${customClassName}`.trim();

  return (
    <nav className={finalClassName} aria-label="面包屑导航">
      <ol className="flex items-center space-x-2 text-sm text-gray-500 mb-0">
        <li>
          <Link to="/" className="hover:text-primary-600 flex items-center">
            <i className="ri-home-line mr-1" />
            首页
          </Link>
        </li>
        
        {breadcrumbs.map((item, index) => (
          <li key={index} className="flex items-center">
            <i className="ri-arrow-right-s-line mx-1 text-gray-400" />
            {index === breadcrumbs.length - 1 ? (
              <span className="text-gray-900 font-medium">{item.title}</span>
            ) : (
              <Link
                to={item.to || '#'}
                className="hover:text-primary-600"
                prefetch="intent"
                preventScrollReset={false}
              >
                {item.title}
              </Link>
            )}
          </li>
        ))}
      </ol>
    </nav>
  );
}