import Image from '@/components/image';
import SvgIcon from '@/components/svg-icon';
import { IReference, IReferenceChunk } from '@/interfaces/database/chat';
import { getExtension } from '@/utils/document-util';
import DOMPurify from 'dompurify';
import { memo, useCallback, useEffect, useMemo } from 'react';
import Markdown from 'react-markdown';
import SyntaxHighlighter from 'react-syntax-highlighter';
import rehypeKatex from 'rehype-katex';
import rehypeRaw from 'rehype-raw';
import remarkGfm from 'remark-gfm';
import remarkMath from 'remark-math';
import { visitParents } from 'unist-util-visit-parents';

import { useTranslation } from 'react-i18next';

import 'katex/dist/katex.min.css'; // `rehype-katex` does not import the CSS for you

import {
  currentReg,
  parseCitationIndex,
  preprocessLaTeX,
  replaceTextByOldReg,
  replaceThinkToSection,
} from '@/utils/chat';
import { citationMarkerReg } from '@/utils/citation-utils';
import { getDirAttribute } from '@/utils/text-direction';

import { Button } from '@/components/ui/button';
import {
  Popover,
  PopoverContent,
  PopoverTrigger,
} from '@/components/ui/popover';
import { useFetchDocumentThumbnailsByIds } from '@/hooks/use-document-request';
import classNames from 'classnames';
import { omit } from 'lodash';
import { pipe } from 'lodash/fp';
import reactStringReplace from 'react-string-replace';

// Defining Tailwind CSS class name constants
const styles = {
  referenceChunkImage: 'w-[10vw] object-contain',
  referenceInnerChunkImage: 'block object-contain max-w-full max-h-[6vh]',
  referenceImagePreview: 'max-w-[45vw] max-h-[45vh]',
  chunkContentText: 'max-h-[45vh] overflow-y-auto',
  documentLink: 'p-0',
  referenceIcon: 'px-[6px]',
  fileThumbnail: 'inline-block max-w-[40px]',
};

const getChunkIndex = (match: string) => parseCitationIndex(match);

// TODO: The display of the table is inconsistent with the display previously placed in the MessageItem.
const MarkdownContent = ({
  reference,
  clickDocumentButton,
  content,
}: {
  content: string;
  loading: boolean;
  reference: IReference;
  clickDocumentButton?: (documentId: string, chunk: IReferenceChunk) => void;
}) => {
  const { t } = useTranslation();
  const { setDocumentIds, data: fileThumbnails } =
    useFetchDocumentThumbnailsByIds();
  const contentWithCursor = useMemo(() => {
    let text = DOMPurify.sanitize(content, {
      ADD_TAGS: ['think', 'section'],
      ADD_ATTR: ['class'],
    });
    // let text = content;
    if (text === '') {
      text = t('chat.searching');
    }
    const nextText = replaceTextByOldReg(text);
    return pipe(replaceThinkToSection, preprocessLaTeX)(nextText);
  }, [content, t]);

  useEffect(() => {
    const docAggs = reference?.doc_aggs;
    setDocumentIds(Array.isArray(docAggs) ? docAggs.map((x) => x.doc_id) : []);
  }, [reference, setDocumentIds]);

  const handleDocumentButtonClick = useCallback(
    (
      documentId: string,
      chunk: IReferenceChunk,
      isPdf: boolean = false,
      documentUrl?: string,
    ) =>
      () => {
        clickDocumentButton?.(documentId, chunk);
      },
    [clickDocumentButton],
  );

  const rehypeWrapReference = () => {
    return function wrapTextTransform(tree: any) {
      visitParents(tree, 'text', (node, ancestors) => {
        const latestAncestor = ancestors.at(-1);
        if (
          latestAncestor.tagName !== 'custom-typography' &&
          latestAncestor.tagName !== 'code'
        ) {
          node.type = 'element';
          node.tagName = 'custom-typography';
          node.properties = {};
          node.children = [{ type: 'text', value: node.value }];
        }
      });
    };
  };

  const getReferenceInfo = useCallback(
    (chunkIndex: number) => {
      const chunks = reference?.chunks ?? [];
      const chunkItem = chunks[chunkIndex];
      const document = reference?.doc_aggs?.find(
        (x) => x?.doc_id === chunkItem?.document_id,
      );
      const documentId = document?.doc_id;
      const documentUrl = document?.url;
      const fileThumbnail = documentId ? fileThumbnails[documentId] : '';
      const fileExtension = documentId ? getExtension(document?.doc_name) : '';
      const imageId = chunkItem?.image_id;

      return {
        documentUrl,
        fileThumbnail,
        fileExtension,
        imageId,
        chunkItem,
        documentId,
        document,
      };
    },
    [fileThumbnails, reference],
  );

  const getPopoverContent = useCallback(
    (chunkIndex: number) => {
      const {
        fileThumbnail,
        fileExtension,
        imageId,
        chunkItem,
        documentId,
        document,
      } = getReferenceInfo(chunkIndex);

      return (
        <div key={chunkItem?.id} className="flex gap-2">
          {imageId && (
            <Popover>
              <PopoverTrigger>
                <Image
                  id={imageId}
                  className={styles.referenceChunkImage}
                ></Image>
              </PopoverTrigger>
              <PopoverContent>
                <Image
                  id={imageId}
                  className={styles.referenceImagePreview}
                ></Image>
              </PopoverContent>
            </Popover>
          )}
          <div className={'space-y-2 max-w-[40vw]'}>
            <div
              dangerouslySetInnerHTML={{
                __html: DOMPurify.sanitize(chunkItem?.content ?? ''),
              }}
              className={classNames(styles.chunkContentText)}
            ></div>
            {documentId && (
              <div className="flex gap-2">
                {fileThumbnail ? (
                  <img
                    src={fileThumbnail}
                    alt=""
                    className={styles.fileThumbnail}
                  />
                ) : (
                  <SvgIcon
                    name={`file-icon/${fileExtension}`}
                    width={24}
                  ></SvgIcon>
                )}
                <Button
                  variant="link"
                  className={classNames(
                    styles.documentLink,
                    'text-wrap flex-1 h-auto',
                  )}
                  onClick={handleDocumentButtonClick(
                    documentId,
                    chunkItem,
                    // fileExtension === 'pdf',
                    // documentUrl,
                  )}
                >
                  {document?.doc_name}
                </Button>
              </div>
            )}
          </div>
        </div>
      );
    },
    [getReferenceInfo, handleDocumentButtonClick],
  );

  const renderReference = useCallback(
    (text: string) => {
      let replacedText = reactStringReplace(text, currentReg, (match) => {
        const chunkIndex = getChunkIndex(match);

        return (
          <Popover>
            <PopoverTrigger>
              <span className="text-text-secondary bg-bg-card rounded-2xl px-1 mx-1 text-nowrap">
                Fig. {chunkIndex + 1}
              </span>
            </PopoverTrigger>
            <PopoverContent className="!w-fit">
              {getPopoverContent(chunkIndex)}
            </PopoverContent>
          </Popover>
        );
      });

      return replacedText;
    },
    [getPopoverContent],
  );

  const dir = getDirAttribute(content.replace(citationMarkerReg, ''));

  return (
    <div
      dir={dir}
      className="[&>section.think]:pl-[10px] [&>section.think]:text-[#8b8b8b] [&>section.think]:border-l-2 [&>section.think]:border-l-[#d5d3d3] [&>section.think]:mb-[10px] [&>section.think]:text-xs [&>blockquote]:pl-[10px] [&>blockquote]:border-l-4 [&>blockquote]:border-l-[#ccc] text-sm"
    >
      <Markdown
        rehypePlugins={[rehypeWrapReference, rehypeKatex, rehypeRaw]}
        remarkPlugins={[remarkGfm, remarkMath]}
        components={
          {
            p: ({ children, node, ...props }: any) => (
              <p {...props}>{children}</p>
            ),
            'custom-typography': ({ children }: { children: string }) =>
              renderReference(children),
            code(props: any) {
              const { children, className, ...rest } = props;
              const restProps = omit(rest, 'node');
              const match = /language-(\w+)/.exec(className || '');
              return match ? (
                <SyntaxHighlighter
                  {...restProps}
                  PreTag="div"
                  language={match[1]}
                  wrapLongLines
                >
                  {String(children).replace(/\n$/, '')}
                </SyntaxHighlighter>
              ) : (
                <code
                  {...restProps}
                  className={classNames(className, 'text-wrap')}
                >
                  {children}
                </code>
              );
            },
          } as any
        }
      >
        {contentWithCursor}
      </Markdown>
    </div>
  );
};

export default memo(MarkdownContent);
