import { visit } from 'unist-util-visit';

/**
 * 自定义 remark 插件来处理 citation 标记
 */
export const remarkCitation = () => {
  return (tree) => {
    visit(tree, 'text', (node, index, parent) => {
      const citationRegex = /\[CIT:(\d+)]/g;
      const matches = [...node.value.matchAll(citationRegex)];

      if (matches.length === 0) return;

      const newChildren = [];
      let lastIndex = 0;

      matches.forEach((match) => {
        const [fullMatch, num] = match;
        const startIndex = match.index;

        // 添加匹配前的文本
        if (startIndex > lastIndex) {
          newChildren.push({
            type: 'text',
            value: node.value.slice(lastIndex, startIndex),
          });
        }

        // 添加citations节点
        newChildren.push({
          type: 'citations',
          data: {
            hName: 'citations',
            hProperties: {
              dataNums: num,
            },
          },
          children: [{ type: 'text', value: num }],
        });

        lastIndex = startIndex + fullMatch.length;
      });

      // 添加剩余文本
      if (lastIndex < node.value.length) {
        newChildren.push({
          type: 'text',
          value: node.value.slice(lastIndex),
        });
      }

      // 替换原节点
      parent.children.splice(index, 1, ...newChildren);
    });
  };
};

/**
 * 自定义 remark 插件来处理 <think> 标签
 * 将 <think>.....</think> 转换为自定义节点
 */
export const remarkThink = () => {
  return (tree) => {
    visit(tree, 'text', (node, index, parent) => {
      const thinkRegex = /<think>([\s\S]*?)<\/think>/g;
      const matches = [...node.value.matchAll(thinkRegex)];

      if (matches.length === 0) return;

      const newChildren = [];
      let lastIndex = 0;

      matches.forEach((match) => {
        const [fullMatch, content] = match;
        const startIndex = match.index;

        // 添加匹配前的文本
        if (startIndex > lastIndex) {
          newChildren.push({
            type: 'text',
            value: node.value.slice(lastIndex, startIndex),
          });
        }

        // 添加 think 节点
        newChildren.push({
          type: 'thinkBlock',
          data: {
            hName: 'thinkBlock',
            hProperties: {
              content: content,
            },
          },
          children: [{ type: 'text', value: content }],
        });

        lastIndex = startIndex + fullMatch.length;
      });

      // 添加剩余文本
      if (lastIndex < node.value.length) {
        newChildren.push({
          type: 'text',
          value: node.value.slice(lastIndex),
        });
      }

      // 替换原节点
      parent.children.splice(index, 1, ...newChildren);
    });
  };
};

export default remarkCitation;