// Inspired by Chatbot-UI and modified to fit the needs of this project
// @see https://github.com/mckaywrigley/chatbot-ui/blob/main/components/Chat/ChatMessage.tsx

import remarkGfm from 'remark-gfm';
import remarkMath from 'remark-math';

import { cn } from '@/lib/utils';
import { CodeBlock } from '@/components/ui/CodeBlock';
import { MemoizedReactMarkdown } from '@/components/chat/MemoizedReactMarkdown';
import { IconOpenAI, IconUser } from '@/components/ui/Icons';
import { ChatMessageActions } from '@/components/chat/ChatMessageActions';
import { MessageBase } from '../../lib/types';

export interface ChatMessageProps {
  message: MessageBase;
}


const PAIRS: Record<string, string> = {
  '┍': '┑',
  '┝': '┥',
  '├': '┤',
  '┕': '┙',
};

const MIDDLE_STARTER = '┝';
const MIDDLE_SEPARATOR = '┿';

export function ChatMessage({ message, ...props }: ChatMessageProps) {
  const cleanupMessage = ({ content, role }: MessageBase) => {
    if (role === 'user') {
      return {
        content,
      };
    }
    const [logs = '', answer = ''] = content.split('<ANSWER>');
    const cleanedLogs = [];
    let left = 0;
    let right = 0;
    while (right < logs.length) {
      if (Object.keys(PAIRS).includes(content[right])) {
        cleanedLogs.push(content.substring(left, right));
        left = right++;
        while (
          right < content.length &&
          PAIRS[content[left]] !== content[right]
        ) {
          right++;
        }
        if (content[left] === MIDDLE_STARTER) {
          // add the text alignment so it can be shown as a table
          const separators = logs
            .substring(left, right)
            .split(MIDDLE_SEPARATOR).length;
          if (separators > 0) {
            cleanedLogs.push(
              Array(separators + 1)
                .fill('|')
                .join(' :- '),
            );
          }
        }
        left = ++right;
      } else {
        right++;
      }
    }
    cleanedLogs.push(content.substring(left, right));
    return {
      logs: cleanedLogs
        .join('')
        .replace(/│/g, '|')
        .split('|\n\n|')
        .join('|\n|'),
      content: answer.replace('</</ANSWER>', '').replace('</ANSWER>', ''),
    };
  };

  const { logs, content } = cleanupMessage(message);
  return (
    <div className={cn('group relative mb-4 flex items-start')} {...props}>
      <div
        className={cn(
          'flex size-8 shrink-0 select-none items-center justify-center rounded-md border shadow',
          message.role === 'user'
            ? 'bg-background'
            : 'bg-primary text-primary-foreground',
        )}
      >
        {message.role === 'user' ? <IconUser /> : <IconOpenAI />}
      </div>
      <div className="flex-1 px-1 ml-4 space-y-2 overflow-hidden">
        {logs && message.role !== 'user' && (
          <div className="bg-slate-100 mb-4 p-4 max-h-60 overflow-auto">
            <div className="text-xl font-bold">Thinking Process</div>
            <MemoizedReactMarkdown
              className="break-words text-sm"
              remarkPlugins={[remarkGfm, remarkMath]}
              components={{
                p({ children }) {
                  return (
                    <p className="my-2 last:mb-0 whitespace-pre-line">
                      {children}
                    </p>
                  );
                },
                code({ children, ...props }) {
                  return (
                    <code className="whitespace-pre-line">{children}</code>
                  );
                },
              }}
            >
              {logs}
            </MemoizedReactMarkdown>
          </div>
        )}
        <MemoizedReactMarkdown
          className="break-words"
          remarkPlugins={[remarkGfm, remarkMath]}
          components={{
            p({ children }) {
              return (
                <p className="my-2 last:mb-0 whitespace-pre-line">{children}</p>
              );
            },
            code({ node, inline, className, children, ...props }) {
              if (children.length) {
                if (children[0] == '▍') {
                  return (
                    <span className="mt-1 cursor-default animate-pulse">▍</span>
                  );
                }

                children[0] = (children[0] as string).replace('`▍`', '▍');
              }

              const match = /language-(\w+)/.exec(className || '');
              if (inline) {
                return (
                  <code className={className} {...props}>
                    {children}
                  </code>
                );
              }

              return (
                <CodeBlock
                  key={Math.random()}
                  language={(match && match[1]) || ''}
                  value={String(children).replace(/\n$/, '')}
                  {...props}
                />
              );
            },
          }}
        >
          {content}
        </MemoizedReactMarkdown>
        <ChatMessageActions message={message} />
      </div>
    </div>
  );
}