import React, { useEffect, useRef, useState, useMemo } from 'react';
import { Box, Typography, Paper, Avatar, IconButton, List, ListItem, ListItemIcon, ListItemText, useTheme } from '@mui/material';
import ChevronRightIcon from '@mui/icons-material/ChevronRight';
import type { DocumentMetadata } from '../../../electron/types';
import ReactMarkdown from 'react-markdown';
import rehypeHighlight from 'rehype-highlight';
import 'highlight.js/styles/github.css';
import { Keyboard, Waves, Shield, DataObject, Folder, Lock } from '@mui/icons-material';

interface ChatMessage {
  id: string;
  text: string;
  isUser: boolean;
  timestamp: string;
  sources?: DocumentMetadata[];
  avatar?: string;
}

interface MessageListProps {
  messages: ChatMessage[];
}

export default function MessageList({ messages }: MessageListProps) {
  const messageListRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (messageListRef.current) {
      messageListRef.current.scrollTop = messageListRef.current.scrollHeight;
    }
  }, [messages]);

  return (
    <Box 
      ref={messageListRef}
      sx={{ 
        flex: 1, 
        overflow: 'auto',
        p: 2,
        display: 'flex',
        flexDirection: 'column',
        gap: 2,
        scrollBehavior: 'smooth',
        '&::-webkit-scrollbar': {
          width: '8px',
          background: 'transparent',
        },
        '&::-webkit-scrollbar-thumb': {
          background: (theme) => theme.palette.divider,
          borderRadius: '4px',
          '&:hover': {
            background: (theme) => theme.palette.action.hover,
          },
        },
        '&::-webkit-scrollbar-track': {
          background: 'transparent',
        },
    }}>

      {messages.length>0 ? (
<>

{messages.map((message) => (
        <Box
          key={message.id}
          sx={{
            display: 'flex',
            flexDirection: message.isUser ? 'row-reverse' : 'row',
            alignItems: 'flex-start',
            gap: 2,
            maxWidth: message.isUser ? '80%' : '100%',
            alignSelf: message.isUser ? 'flex-end' : 'stretch',
          }}
        >
          <Box sx={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 0.5 }}>
            <Avatar
              src={message.isUser ? '/profiles/user-profile.webp' : '/profiles/ai-profile.webp'}
              alt={message.isUser ? 'User' : 'AI'}
              variant="square"
              sx={{ 
                width: 40, 
                height: 40,
                boxShadow: 1
              }}
            />
            <Typography 
              variant="caption" 
              sx={{ 
                fontSize: '0.75rem',
                color: 'text.secondary',
                fontWeight: 500
              }}
            >
              {message.isUser ? 'User' : 'Data Identification Manager'}
            </Typography>
          </Box>
          <Box
            component={Paper}
            elevation={1}
            sx={{
              px: 2.5, // Keep horizontal padding
              py: message.text.includes('<think>') ? 0 : 1.5, // Reduce vertical padding
              pb: 1.5,
            flex: 1,
            bgcolor: message.isUser ? 'primary.main' : 'background.paper',
            color: message.isUser ? 'primary.contrastText' : 'text.primary',
            transition: 'all 0.2s ease-in-out',
            boxShadow: 1,
            borderRadius: 2,
            '&:hover': {
              boxShadow: 2,
            },
          }}
        >
          <Box sx={{ 
            '& .markdown-body': {
            wordBreak: 'break-word',
            minHeight: '1.5em',
            lineHeight: 1.6,
            '& pre': {
              backgroundColor: (theme) => theme.palette.mode === 'dark' ? '#1e1e1e' : '#f6f8fa',
              padding: 0,
              borderRadius: 1,
              overflow: 'auto'
            },
            '& code': {
              backgroundColor: (theme) => theme.palette.mode === 'dark' ? '#1e1e1e' : '#f6f8fa',
              borderRadius: 1,
              fontSize: '85%'
            },
            '& h1, & h2, & h3, & h4, & h5, & h6': {
              marginTop: '0px', // Reduced from 24px
              marginBottom: '0px', // Added margin bottom for headers
              fontWeight: 600,
              lineHeight: 1.25
            },
            '& p': {
              marginTop: '0',
              marginBottom: '0px' // Added margin bottom for paragraphs
            },
            '& a': {
              color: (theme) => theme.palette.primary.main,
              textDecoration: 'none',
              '&:hover': {
                textDecoration: 'underline'
              }
            },
            '& img': {
              maxWidth: '100%',
              height: 'auto'
            },
            '& blockquote': {
              padding: '0 1em',
              color: (theme) => theme.palette.text.secondary,
              borderLeft: (theme) => `0.25em solid ${theme.palette.divider}`,
              margin: '0 0 0px 0'
            },
            '& ul, & ol': {
              paddingLeft: '2em',
              marginTop: '0px',    // Added margin top
              marginBottom: '0px'
            },
            '& li': {             // Added specific list item styling
              marginBottom: '0px'  // Add space between list items
            },
            '& li:last-child': {  // Remove bottom margin from last list item
              marginBottom: '0'
            },
            '& li > p': {         // Adjust paragraph spacing within list items
              marginBottom: '0px'
            },
            '& li > p:last-child': {
              marginBottom: '0'
            }
          }
          }}>
            {message.text.includes('<think>') || message.text.length==0 ? (
              message.text.split(/<think>|<\/think>/).map((segment, index) => {
                if (index % 2 === 1) { // This is a thinking section
                  // Calculate thinking time - assume 1 character = 0.1s
                  const thinkingTime = (segment.length * 0.1).toFixed(1);
                  
                  return (
                    <div key={index} className="thinking-section">
                      <div 
                        className="thinking-header" 
                        onClick={() => {
                          const content = document.getElementById(`thinking-content-${message.id}-${index}`);
                          const indicator = document.getElementById(`thinking-indicator-${message.id}-${index}`);
                          if (content && indicator) {
                            content.classList.toggle('open');
                            indicator.classList.toggle('open');
                          }
                        }}
                      >
                        <div className="thinking-header-left">
                          <ChevronRightIcon 
                            id={`thinking-indicator-${message.id}-${index}`}
                            className="indicator" 
                          />
                          <span>Reasoning</span>
                        </div>
                        <span className="timestamp">(thought for {thinkingTime}ms)</span>
                      </div>
                      <div 
                        id={`thinking-content-${message.id}-${index}`}
                        className="thinking-content"
                      >
                      <ReactMarkdown
                        key={index}
                        className="markdown-body"
                        rehypePlugins={[rehypeHighlight]}
                      >
                        {segment}
                      </ReactMarkdown>
                      </div>
                    </div>
                  );
                } else if (segment.includes('Sorry, there was an error processing your request.')) {
                  return (
                    <div key={index} className="error-message">
                      {segment}
                    </div>
                  );
                }
                return (
                  <ReactMarkdown
                    key={index}
                    className="markdown-body"
                    rehypePlugins={[rehypeHighlight]}
                  >
                    {segment}
                  </ReactMarkdown>
                );
              })
            ) : (
              <ReactMarkdown
                className="markdown-body"
                rehypePlugins={[rehypeHighlight]}
              >
                {message.text}
              </ReactMarkdown>
            )}
          </Box>
          {message.sources && message.sources.length > 0 && (
            <Box sx={{ mt: 1, pt: 0, borderTop: '1px solid', borderColor: 'divider' }}>
              <Typography 
                variant="caption" 
                color="text.secondary"
                sx={{ 
                  display: 'block',
                  mb: 0.5,
                  fontWeight: 'medium'
                }}
              >
                Sources:
              </Typography>
              {message.sources.map((source, index) => (
                <Typography
                  key={index}
                  variant="caption"
                  component="div"
                  color="text.secondary"
                  sx={{ 
                    pl: 1,
                    borderLeft: '2px solid',
                    borderColor: 'divider'
                  }}
                >
                  {source.path}
                </Typography>
              ))}
            </Box>
          )}
          </Box>
        </Box>
      ))}
      </>
      ):(
        <>
          <WelcomeMessage/>
        </>
      )}
    </Box>
  );
}



const WelcomeMessage = () => {
  const [text, setText] = useState('');
  const fullText = 'Send a message...';
  const [showCursor, setShowCursor] = useState(true);
  const theme = useTheme();

  useEffect(() => {
    if (text.length < fullText.length) {
      const timeout = setTimeout(() => {
        setText(fullText.slice(0, text.length + 1));
      }, 100);
      return () => clearTimeout(timeout);
    }
  }, [text]);

  useEffect(() => {
    const cursorInterval = setInterval(() => {
      setShowCursor(prev => !prev);
    }, 530);
    return () => clearInterval(cursorInterval);
  }, []);

  return (
    <Paper 
      elevation={0}
      sx={{
        width: '100%',
        maxWidth: '4xl',
        mx: 'auto',
        p: 4,
        background: 'rgb(0,0,0,0)',
      }}
    >
      <Box sx={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 3 }}>
        {/* Animated Keyboard and Hands */}
        <Box sx={{ position: 'relative' }}>
          <Keyboard 
            style={{ 
              width: 64, 
              height: 64, 
              color: theme.palette.primary.main,
              animation: 'pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite'
            }} 
          />
          <Box 
            sx={{ 
              position: 'absolute', 
              bottom: -16, 
              left: '50%', 
              transform: 'translateX(-50%)'
            }}
          >
            <Waves 
              style={{ 
                width: 32, 
                height: 32, 
                color: theme.palette.primary.light,
                animation: 'bounce 1s infinite'
              }} 
            />
          </Box>
        </Box>

        {/* Typing Animation */}
        <Typography 
          variant="h4" 
          sx={{ 
            fontWeight: 600,
            color: theme.palette.text.primary,
            mt: 2
          }}
        >
          {text}
          <Box 
            component="span" 
            sx={{ 
              ml: 0.5,
              opacity: showCursor ? 1 : 0,
              transition: 'opacity 0.3s'
            }}
          >
            |
          </Box>
        </Typography>

        {/* Example Questions */}
        <List sx={{ width: '100%', mt: 4 }}>
          <ListItem 
            component={Paper} 
            elevation={1}
            sx={{ 
              mb: 2, 
              borderRadius: 1,
              transition: 'box-shadow 0.3s',
              '&:hover': { boxShadow: 3 }
            }}
          >
            <ListItemIcon>
              <Folder style={{ color: theme.palette.primary.main }} />
            </ListItemIcon>
            <ListItemText 
              primary="Can you analyze my CSV file and create a visualization of the trends?"
              sx={{ color: theme.palette.text.primary }}
            />
          </ListItem>

          <ListItem 
            component={Paper} 
            elevation={1}
            sx={{ 
              mb: 2, 
              borderRadius: 1,
              transition: 'box-shadow 0.3s',
              '&:hover': { boxShadow: 3 }
            }}
          >
            <ListItemIcon>
              <Shield style={{ color: theme.palette.success.main }} />
            </ListItemIcon>
            <ListItemText 
              primary="What security measures does Data443 implement for data protection?"
              sx={{ color: theme.palette.text.primary }}
            />
          </ListItem>

          <ListItem 
            component={Paper} 
            elevation={1}
            sx={{ 
              mb: 2, 
              borderRadius: 1,
              transition: 'box-shadow 0.3s',
              '&:hover': { boxShadow: 3 }
            }}
          >
            <ListItemIcon>
              <Lock style={{ color: theme.palette.secondary.main }} />
            </ListItemIcon>
            <ListItemText 
              primary="How can Data443's products help with GDPR compliance?"
              sx={{ color: theme.palette.text.primary }}
            />
          </ListItem>
        </List>

        {/* Footer Note */}
        <Typography 
          variant="body2" 
          sx={{ 
            color: theme.palette.text.secondary,
            textAlign: 'center',
            mt: 3
          }}
        >
          Ask me anything about your data, security needs, or Data443 products
        </Typography>
      </Box>
    </Paper>
  );
};