import type { RefObject } from 'react';
import type {
  HTMLPreviewHander,
} from './artifacts';
import clsx from 'clsx';
import mermaid from 'mermaid';
import React, { useEffect, useMemo, useRef, useState } from 'react';
import ReactMarkdown from 'react-markdown';
import RehypeHighlight from 'rehype-highlight';
import RehypeKatex from 'rehype-katex';
import RemarkBreaks from 'remark-breaks';
import RemarkGfm from 'remark-gfm';
import RemarkMath from 'remark-math';
import { useDebouncedCallback } from 'use-debounce';
import ReloadButtonIcon from '../icons/reload.svg';
import LoadingIcon from '../icons/three-dots.svg';
import Locale from '../locales';
import { useChatStore } from '../store';
import { useAppConfig } from '../store/config';
import { copyToClipboard, useWindowSize } from '../utils';
import {
  ArtifactsShareButton,
  HTMLPreview,
} from './artifacts';
import { IconButton } from './button';

import { FullScreen, showImageModal } from './ui-lib';
import 'katex/dist/katex.min.css';

export function Mermaid(props: { code: string }) {
  const ref = useRef<HTMLDivElement>(null);
  const [hasError, setHasError] = useState(false);

  useEffect(() => {
    if (props.code && ref.current) {
      mermaid
        .run({
          nodes: [ref.current],
          suppressErrors: true,
        })
        .catch((e) => {
          setHasError(true);
          console.error('[Mermaid] ', e.message);
        });
    }
  }, [props.code]);

  function viewSvgInNewWindow() {
    const svg = ref.current?.querySelector('svg');
    if (!svg)
    { return; }
    const text = new XMLSerializer().serializeToString(svg);
    const blob = new Blob([text], { type: 'image/svg+xml' });
    showImageModal(URL.createObjectURL(blob));
  }

  if (hasError) {
    return null;
  }

  return (
    <div
      className={clsx('no-dark', 'mermaid')}
      style={{
        cursor: 'pointer',
        overflow: 'auto',
      }}
      ref={ref}
      onClick={() => viewSvgInNewWindow()}
    >
      {props.code}
    </div>
  );
}

export function PreCode(props: { children: any }) {
  const ref = useRef<HTMLPreElement>(null);
  const previewRef = useRef<HTMLPreviewHander>(null);
  const [mermaidCode, setMermaidCode] = useState('');
  const [htmlCode, setHtmlCode] = useState('');
  const { height } = useWindowSize();
  const chatStore = useChatStore();
  const session = chatStore.currentSession();

  const renderArtifacts = useDebouncedCallback(() => {
    if (!ref.current)
    { return; }
    const mermaidDom = ref.current.querySelector('code.language-mermaid');
    if (mermaidDom) {
      setMermaidCode((mermaidDom as HTMLElement).innerText);
    }
    const htmlDom = ref.current.querySelector('code.language-html');
    const refText = ref.current.querySelector('code')?.innerText;
    if (htmlDom) {
      setHtmlCode((htmlDom as HTMLElement).innerText);
    } else if (
      refText?.startsWith('<!DOCTYPE')
      || refText?.startsWith('<svg')
      || refText?.startsWith('<?xml')
    ) {
      setHtmlCode(refText);
    }
  }, 600);

  const config = useAppConfig();
  const enableArtifacts
    = session.mask?.enableArtifacts !== false && config.enableArtifacts;

  // Wrap the paragraph for plain-text
  useEffect(() => {
    if (ref.current) {
      const codeElements = ref.current.querySelectorAll(
        'code',
      ) as NodeListOf<HTMLElement>;
      const wrapLanguages = [
        '',
        'md',
        'markdown',
        'text',
        'txt',
        'plaintext',
        'tex',
        'latex',
      ];
      codeElements.forEach((codeElement) => {
        const languageClass = codeElement.className.match(/language-(\w+)/);
        const name = languageClass ? languageClass[1] : '';
        if (wrapLanguages.includes(name)) {
          codeElement.style.whiteSpace = 'pre-wrap';
        }
      });
      setTimeout(renderArtifacts, 1);
    }
  }, []);

  return (
    <>
      <pre ref={ref}>
        <span
          className="copy-code-button"
          onClick={() => {
            if (ref.current) {
              copyToClipboard(
                ref.current.querySelector('code')?.innerText ?? '',
              );
            }
          }}
        >
        </span>
        {props.children}
      </pre>
      {mermaidCode.length > 0 && (
        <Mermaid code={mermaidCode} key={mermaidCode} />
      )}
      {htmlCode.length > 0 && enableArtifacts && (
        <FullScreen className="no-dark html" right={70}>
          <ArtifactsShareButton
            style={{ position: 'absolute', right: 20, top: 10 }}
            getCode={() => htmlCode}
          />
          <IconButton
            style={{ position: 'absolute', right: 120, top: 10 }}
            bordered
            icon={<ReloadButtonIcon />}
            shadow
            onClick={() => previewRef.current?.reload()}
          />
          <HTMLPreview
            ref={previewRef}
            code={htmlCode}
            autoHeight={!document.fullscreenElement}
            height={!document.fullscreenElement ? 600 : height}
          />
        </FullScreen>
      )}
    </>
  );
}

function CustomCode(props: { children: any; className?: string }) {
  const chatStore = useChatStore();
  const session = chatStore.currentSession();
  const config = useAppConfig();
  const enableCodeFold
    = session.mask?.enableCodeFold !== false && config.enableCodeFold;

  const ref = useRef<HTMLPreElement>(null);
  const [collapsed, setCollapsed] = useState(true);
  const [showToggle, setShowToggle] = useState(false);

  useEffect(() => {
    if (ref.current) {
      const codeHeight = ref.current.scrollHeight;
      setShowToggle(codeHeight > 400);
      ref.current.scrollTop = ref.current.scrollHeight;
    }
  }, [props.children]);

  const toggleCollapsed = () => {
    setCollapsed(collapsed => !collapsed);
  };
  const renderShowMoreButton = () => {
    if (showToggle && enableCodeFold && collapsed) {
      return (
        <div
          className={clsx('show-hide-button', {
            collapsed,
            expanded: !collapsed,
          })}
        >
          <button onClick={toggleCollapsed}>{Locale.NewChat.More}</button>
        </div>
      );
    }
    return null;
  };
  return (
    <>
      <code
        className={clsx(props?.className)}
        ref={ref}
        style={{
          maxHeight: enableCodeFold && collapsed ? '400px' : 'none',
          overflowY: 'hidden',
        }}
      >
        {props.children}
      </code>

      {renderShowMoreButton()}
    </>
  );
}

function escapeBrackets(text: string) {
  const pattern
    = /(```[\s\S]*?```|`.*?`)|\\\[([\s\S]*?[^\\])\\\]|\\\((.*?)\\\)/g;
  return text.replace(
    pattern,
    (match, codeBlock, squareBracket, roundBracket) => {
      if (codeBlock) {
        return codeBlock;
      } else if (squareBracket) {
        return `$$${squareBracket}$$`;
      } else if (roundBracket) {
        return `$${roundBracket}$`;
      }
      return match;
    },
  );
}

function tryWrapHtmlCode(text: string) {
  // try add wrap html code (fixed: html codeblock include 2 newline)
  // ignore embed codeblock
  if (text.includes('```')) {
    return text;
  }
  return text
    .replace(
      /(`*)(\w*)([\n\r]*)(<!DOCTYPE html>)/g,
      (match, quoteStart, lang, newLine, doctype) => {
        return !quoteStart ? `\n\`\`\`html\n${doctype}` : match;
      },
    )
    .replace(
      /(<\/body>)(\s*)(<\/html>)([\n\r]*)(`*)([\n\r]*?)/g,
      (match, bodyEnd, space, htmlEnd, newLine, quoteEnd) => {
        return !quoteEnd ? `${bodyEnd + space + htmlEnd}\n\`\`\`\n` : match;
      },
    );
}

function _MarkDownContent(props: { content: string }) {
  const escapedContent = useMemo(() => {
    return tryWrapHtmlCode(escapeBrackets(props.content));
  }, [props.content]);

  return (
    <ReactMarkdown
      remarkPlugins={[RemarkMath, RemarkGfm, RemarkBreaks]}
      rehypePlugins={[
        RehypeKatex,
        [
          RehypeHighlight,
          {
            detect: false,
            ignoreMissing: true,
          },
        ],
      ]}
      components={{
        pre: PreCode,
        code: CustomCode,
        p: pProps => <p {...pProps} dir="auto" />,
        a: (aProps) => {
          const href = aProps.href || '';
          if (/\.(aac|mp3|opus|wav)$/.test(href)) {
            return (
              <figure>
                <audio controls src={href}></audio>
              </figure>
            );
          }
          if (/\.(3gp|3g2|webm|ogv|mpeg|mp4|avi)$/.test(href)) {
            return (
              <video controls width="99.9%">
                <source src={href} />
              </video>
            );
          }
          const isInternal = /^\/#/.test(href);
          const target = isInternal ? '_self' : aProps.target ?? '_blank';
          return <a {...aProps} target={target} />;
        },
      }}
    >
      {escapedContent}
    </ReactMarkdown>
  );
}

export const MarkdownContent = React.memo(_MarkDownContent);

export function Markdown(
  props: {
    content: string;
    loading?: boolean;
    fontSize?: number;
    fontFamily?: string;
    parentRef?: RefObject<HTMLDivElement>;
    defaultShow?: boolean;
  } & React.DOMAttributes<HTMLDivElement>,
) {
  const mdRef = useRef<HTMLDivElement>(null);

  return (
    <div
      className="markdown-body"
      style={{
        fontSize: `${props.fontSize ?? 14}px`,
        fontFamily: props.fontFamily || 'inherit',
      }}
      ref={mdRef}
      onContextMenu={props.onContextMenu}
      onDoubleClickCapture={props.onDoubleClickCapture}
      dir="auto"
    >
      {props.loading
        ? (
            <LoadingIcon />
          )
        : (
            <MarkdownContent content={props.content} />
          )}
    </div>
  );
}