'use client';

import React, { useEffect, useState } from 'react';
import DOMPurify from 'dompurify';
import { formatEmailContent } from '@/lib/utils/email-content';
import { sanitizeHtml } from '@/lib/utils/email-formatter';

/**
 * Interface for email content types
 */
interface ProcessedContent {
  html: string;
  text: string;
  isHtml: boolean;
}

/**
 * Interface for component props
 */
interface EmailContentDisplayProps {
  content: string;
  type?: 'html' | 'text' | 'auto';
  isRawEmail?: boolean;
  className?: string;
}

/**
 * Parse raw email content into HTML and text parts
 * This is a helper function used when processing raw email formats
 */
function parseRawEmail(rawContent: string): { html: string; text: string } {
  // Simple parser for demonstration - in production, use a proper MIME parser
  const hasHtmlPart = rawContent.includes('<html') || 
                      rawContent.includes('<body') || 
                      rawContent.includes('Content-Type: text/html');
  
  if (hasHtmlPart) {
    // Extract HTML part
    let htmlPart = '';
    const htmlMatch = rawContent.match(/<html[\s\S]*<\/html>/i) || 
                      rawContent.match(/<body[\s\S]*<\/body>/i);
    
    if (htmlMatch) {
      htmlPart = htmlMatch[0];
    } else {
      // Fallback extraction
      const parts = rawContent.split(/(?:--boundary|\r\n\r\n)/);
      htmlPart = parts.find(part => 
        part.includes('Content-Type: text/html') || 
        part.includes('<html') || 
        part.includes('<body')
      ) || '';
    }
    
    return {
      html: htmlPart,
      text: rawContent.replace(/<[^>]+>/g, ' ').replace(/\s+/g, ' ').trim()
    };
  }
  
  return {
    html: '',
    text: rawContent
  };
}

/**
 * EmailContentDisplay component - displays formatted email content
 * with proper security, styling and support for different email formats
 */
const EmailContentDisplay: React.FC<EmailContentDisplayProps> = ({
  content,
  type = 'auto',
  isRawEmail = false,
  className = ''
}) => {
  const [processedContent, setProcessedContent] = useState<ProcessedContent>({
    html: '',
    text: '',
    isHtml: false
  });
  
  // Process the email content when it changes
  useEffect(() => {
    if (!content) {
      setProcessedContent({
        html: '',
        text: '',
        isHtml: false
      });
      return;
    }
    
    try {
      if (isRawEmail) {
        // Parse raw email content
        const parsed = parseRawEmail(content);
        
        // Check which content to use based on type and availability
        const useHtml = (type === 'html' || (type === 'auto' && parsed.html)) && !!parsed.html;
        
        if (useHtml) {
          // Use the enhanced sanitizeHtml function from email-formatter
          const sanitizedHtml = sanitizeHtml(parsed.html);
          
          setProcessedContent({
            html: sanitizedHtml,
            text: parsed.text,
            isHtml: true
          });
        } else {
          // Format plain text properly
          const formattedText = formatEmailContent({ text: parsed.text });
          
          setProcessedContent({
            html: formattedText,
            text: parsed.text,
            isHtml: false
          });
        }
      } else {
        // Treat as direct content (not raw email)
        const isHtmlContent = type === 'html' || (
          type === 'auto' && (
            content.includes('<html') || 
            content.includes('<body') || 
            content.includes('<div') || 
            content.includes('<p>') ||
            content.includes('<br')
          )
        );
        
        if (isHtmlContent) {
          // Use the enhanced sanitizeHtml function
          const sanitizedHtml = sanitizeHtml(content);
          
          setProcessedContent({
            html: sanitizedHtml,
            text: content.replace(/<[^>]+>/g, ' ').replace(/\s+/g, ' ').trim(),
            isHtml: true
          });
        } else {
          // Format plain text properly using formatEmailContent
          const formattedText = formatEmailContent({ text: content });
          
          setProcessedContent({
            html: formattedText,
            text: content,
            isHtml: false
          });
        }
      }
    } catch (err) {
      console.error('Error processing email content:', err);
      // Fallback to plain text with basic formatting
      setProcessedContent({
        html: `<div style="white-space: pre-wrap; font-family: monospace;">${content.replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/\n/g, '<br />')}</div>`,
        text: content,
        isHtml: false
      });
    }
  }, [content, type, isRawEmail]);
  
  return (
    <div className={`email-content-container ${className}`}>
      <div 
        className="email-content-viewer"
        style={{
          fontFamily: '-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif',
          fontSize: '15px',
          lineHeight: '1.6',
          color: '#1A202C',
          overflow: 'auto'
        }}
        dangerouslySetInnerHTML={{ __html: processedContent.html }}
      />
    </div>
  );
};

export default EmailContentDisplay;