/**
 * @fileoverview markdown 插件
 * Include marked (https://github.com/markedjs/marked)
 * Include github-markdown-css (https://github.com/sindresorhus/github-markdown-css)
 */
import marked from './marked.min'
let index = 0

function Markdown (vm) {
  this.vm = vm
  vm._ids = {}
}

Markdown.prototype.onUpdate = function (content) {
  if (this.vm.markdown) {
    // return marked(content)
    // 先处理内容，确保只有双波浪号才被解析为删除线
    // 使用临时占位符保护单个波浪号
    let processedContent = content;

    // 1. 先保护双波浪号删除线语法
    processedContent = processedContent.replace(/~~([^~]+?)~~/g, '__STRIKETHROUGH_START__$1__STRIKETHROUGH_END__');

    // 2. 将剩余的单个波浪号转换为HTML实体
    processedContent = processedContent.replace(/~/g, '~');

    // 3. 恢复双波浪号删除线语法
    processedContent = processedContent.replace(/__STRIKETHROUGH_START__/g, '~~').replace(/__STRIKETHROUGH_END__/g, '~~');

    return marked(processedContent, {
      gfm: true,
      breaks: false,
      pedantic: false,
      sanitize: false,
    });
  }
}

Markdown.prototype.onParse = function (node, vm) {
  if (vm.options.markdown) {
    // 中文 id 需要转换，否则无法跳转
    if (vm.options.useAnchor && node.attrs && /[\u4e00-\u9fa5]/.test(node.attrs.id)) {
      const id = 't' + index++
      this.vm._ids[node.attrs.id] = id
      node.attrs.id = id
    }
    if (node.name === 'p' || node.name === 'table' || node.name === 'tr' || node.name === 'th' || node.name === 'td' || node.name === 'blockquote' || node.name === 'pre' || node.name === 'code') {
      node.attrs.class = `md-${node.name} ${node.attrs.class || ''}`
    }
  }
}

export default Markdown