import ReactMarkdown from 'react-markdown'
import 'katex/dist/katex.min.css'
import RemarkMath from 'remark-math'
import RemarkBreaks from 'remark-breaks'
import RehypeKatex from 'rehype-katex'
import RemarkGfm from 'remark-gfm'
import RehypeRaw from 'rehype-raw'
import { flow } from 'lodash-es'
import cn from '@/utils/classnames'
import { customUrlTransform, preprocessLaTeX, preprocessThinkTag } from './markdown-utils'
import {
  AudioBlock,
  CodeBlock,
  Img,
  Link,
  MarkdownButton,
  MarkdownForm,
  Paragraph,
  ScriptBlock,
  ThinkBlock,
  VideoBlock,
} from '@/app/components/base/markdown-blocks'

/**
 * @fileoverview Main Markdown rendering component.
 * This file was refactored to extract individual block renderers and utility functions
 * into separate modules for better organization and maintainability as of [Date of refactor].
 * Further refactoring candidates (custom block components not fitting general categories)
 * are noted in their respective files if applicable.
 */

export function Markdown(props: { content: string; className?: string; customDisallowedElements?: string[] }) {
  const latexContent = flow([
    preprocessThinkTag,
    preprocessLaTeX,
  ])(props.content)

  return (
    <div className={cn('markdown-body', '!text-text-primary', props.className)}>
      <ReactMarkdown
        remarkPlugins={[
          RemarkGfm,
          [RemarkMath, { singleDollarTextMath: false }],
          RemarkBreaks,
        ]}
        rehypePlugins={[
          RehypeKatex,
          RehypeRaw as any,
          // The Rehype plug-in is used to remove the ref attribute of an element
          () => {
            return (tree: any) => {
              const iterate = (node: any) => {
                if (node.type === 'element' && node.properties?.ref)
                  delete node.properties.ref

                if (node.type === 'element' && !/^[a-z][a-z0-9]*$/i.test(node.tagName)) {
                  node.type = 'text'
                  node.value = `<${node.tagName}`
                }

                if (node.children)
                  node.children.forEach(iterate)
              }
              tree.children.forEach(iterate)
            }
          },
        ]}
        urlTransform={customUrlTransform}
        disallowedElements={['iframe', 'head', 'html', 'meta', 'link', 'style', 'body', ...(props.customDisallowedElements || [])]}
        components={{
          code: CodeBlock,
          img: Img,
          video: VideoBlock,
          audio: AudioBlock,
          a: Link,
          p: Paragraph,
          button: MarkdownButton,
          form: MarkdownForm,
          script: ScriptBlock as any,
          details: ThinkBlock,
        }}
      >
        {/* Markdown detect has problem. */}
        {latexContent}
      </ReactMarkdown>
    </div>
  )
}