import React, { useState } from 'react';
import ReactMarkdown from 'react-markdown';
import remarkGfm from 'remark-gfm';
import rehypeRaw from 'rehype-raw';

interface MarkdownRendererProps {
  content: string;
  className?: string;
  onCitationClick?: (index: number) => void;
}

const extractTextFromNode = (node: React.ReactNode): string => {
  if (typeof node === 'string' || typeof node === 'number') return String(node);
  if (Array.isArray(node)) return node.map(extractTextFromNode).join('');
  if (React.isValidElement<{ children?: React.ReactNode }>(node)) return extractTextFromNode(node.props.children);
  return '';
};

const CodeBlock: React.FC<{ children: React.ReactNode; className?: string }> = ({ children, className = '' }) => {
  const [copied, setCopied] = useState(false);
  const codeText = extractTextFromNode(children).replace(/\n$/, '');
  const language = className?.match(/language-(\w+)/)?.[1];

  const handleCopy = async () => {
    try {
      await navigator.clipboard.writeText(codeText);
      setCopied(true);
      window.setTimeout(() => setCopied(false), 1500);
    } catch (error) {
      console.error('复制代码失败:', error);
    }
  };

  return (
    <div className="group relative my-4 overflow-hidden rounded-lg border border-gray-200 bg-gray-50 shadow-sm dark:border-slate-700 dark:bg-slate-900">
      <div className="flex items-center justify-between border-b border-gray-200 bg-gray-100 px-3 py-2 text-xs text-gray-500 dark:border-slate-700 dark:bg-slate-800 dark:text-slate-400">
        <span>{language || 'code'}</span>
        <button
          type="button"
          onClick={handleCopy}
          className="rounded border border-gray-300 bg-white px-2 py-1 text-xs text-gray-600 transition-colors hover:bg-gray-50 dark:border-slate-600 dark:bg-slate-700 dark:text-slate-200 dark:hover:bg-slate-600"
        >
          {copied ? '已复制' : '复制'}
        </button>
      </div>
      <pre className="m-0 overflow-x-auto p-4 text-sm leading-relaxed text-gray-800 dark:text-slate-100">
        <code className={className}>{children}</code>
      </pre>
    </div>
  );
};

const MarkdownRenderer: React.FC<MarkdownRendererProps> = ({ content, className = '', onCitationClick }) => {
  const contentWithCitationBadge = content.replace(
    /\[\[(\d+)\]\]/g,
    '<button type="button" data-citation-index="$1" class="inline-flex items-center justify-center min-w-[1.5rem] h-6 px-2 mx-0.5 rounded-md border text-xs font-semibold align-middle bg-red-50 text-red-600 border-red-200 dark:bg-slate-700 dark:text-slate-100 dark:border-slate-500 cursor-pointer transition-all hover:opacity-85">[$1]</button>',
  );

  return (
    <div
      className={`markdown-content ${className}`}
      onClick={(event) => {
        if (!onCitationClick) return;
        const target = event.target as HTMLElement;
        const button = target.closest('[data-citation-index]') as HTMLElement | null;
        if (!button) return;
        const index = Number(button.dataset.citationIndex || '0');
        if (Number.isNaN(index) || index <= 0) return;
        onCitationClick(index);
      }}
    >
      <ReactMarkdown
        remarkPlugins={[remarkGfm]}
        rehypePlugins={[rehypeRaw]}
        components={{
          h1: ({ node, ...props }) => <h1 className="text-2xl font-bold mb-4" {...props} />,
          h2: ({ node, ...props }) => <h2 className="text-xl font-bold mb-3" {...props} />,
          h3: ({ node, ...props }) => <h3 className="text-lg font-bold mb-2" {...props} />,
          h4: ({ node, ...props }) => <h4 className="text-base font-bold mb-2" {...props} />,
          h5: ({ node, ...props }) => <h5 className="text-sm font-bold mb-2" {...props} />,
          h6: ({ node, ...props }) => <h6 className="text-xs font-bold mb-2" {...props} />,
          p: ({ node, ...props }) => <p className="mb-4 leading-relaxed" {...props} />,
          ul: ({ node, ...props }) => <ul className="list-disc list-inside mb-4 ml-4" {...props} />,
          ol: ({ node, ...props }) => <ol className="list-decimal list-inside mb-4 ml-4" {...props} />,
          li: ({ node, ...props }) => <li className="mb-1" {...props} />,
          // code: ({ node, inline, className, children, ...props }: any) => {
          //   if (inline) {
          //     return (
          //       <code
          //         className={`rounded bg-gray-100 px-1 py-0.5 text-sm text-gray-800 dark:bg-slate-800 dark:text-slate-100 ${className || ''}`}
          //         {...props}
          //       >
          //         {children}
          //       </code>
          //     );
          //   }
          //   return <CodeBlock className={className}>{children}</CodeBlock>;
          // },
          // pre: ({ node, children }) => <>{children}</>,
          blockquote: ({ node, ...props }) => (
            <blockquote className="border-l-4 border-gray-300 dark:border-gray-600 pl-4 italic my-4" {...props} />
          ),
          a: ({ node, ...props }) => (
            <a className="text-blue-600 dark:text-blue-400 hover:underline" {...props} />
          ),
          table: ({ node, ...props }) => (
            <div className="overflow-x-auto mb-4">
              <table className="min-w-full border-collapse" {...props} />
            </div>
          ),
          thead: ({ node, ...props }) => <thead className="bg-gray-100 dark:bg-gray-800" {...props} />,
          tbody: ({ node, ...props }) => <tbody className="divide-y divide-gray-200 dark:divide-gray-700" {...props} />,
          tr: ({ node, ...props }) => <tr className="hover:bg-gray-50 dark:hover:bg-gray-700" {...props} />,
          th: ({ node, ...props }) => <th className="px-4 py-2 text-left font-semibold" {...props} />,
          td: ({ node, ...props }) => <td className="px-4 py-2" {...props} />,
          hr: ({ node, ...props }) => <hr className="my-4 border-gray-300 dark:border-gray-600" {...props} />,
          strong: ({ node, ...props }) => <strong className="font-bold" {...props} />,
          em: ({ node, ...props }) => <em className="italic" {...props} />,
        }}
      >
        {contentWithCitationBadge}
      </ReactMarkdown>
    </div>
  );
};

export default MarkdownRenderer;