import { simpleParser } from 'mailparser';

function cleanHtml(html: string | null | undefined): string {
  if (!html) return '';
  
  try {
    // Basic HTML cleaning without DOMPurify
    return html
      .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '') // Remove script tags
      .replace(/<style\b[^<]*(?:(?!<\/style>)<[^<]*)*<\/style>/gi, '') // Remove style tags
      .replace(/<meta[^>]*>/gi, '') // Remove meta tags
      .replace(/<head[^>]*>[\s\S]*?<\/head>/gi, '') // Remove head
      .replace(/<title[^>]*>[\s\S]*?<\/title>/gi, '') // Remove title
      .replace(/<body[^>]*>/gi, '') // Remove body opening tag
      .replace(/<\/body>/gi, '') // Remove body closing tag
      .replace(/<html[^>]*>/gi, '') // Remove html opening tag
      .replace(/<\/html>/gi, '') // Remove html closing tag
      .replace(/\s+/g, ' ') // Clean up whitespace
      .trim();
  } catch (error) {
    console.error('Error cleaning HTML:', error);
    return html || '';
  }
}

function getAddressText(address: any): string | null {
  if (!address) return null;
  if (Array.isArray(address)) {
    return address.map(addr => addr.value?.[0]?.address || '').filter(Boolean).join(', ');
  }
  return address.value?.[0]?.address || null;
}

export async function parseEmail(emailContent: string) {
  try {
    // Add debug logging for the raw content length
    console.log(`Starting to parse email content (length: ${emailContent ? emailContent.length : 0})`);
    
    const parsed = await simpleParser(emailContent);
    
    // Add debug logging for the parsed content
    console.log('Parsed email fields:', {
      hasSubject: !!parsed.subject,
      hasHtml: !!parsed.html,
      htmlLength: parsed.html?.length || 0,
      hasText: !!parsed.text,
      textLength: parsed.text?.length || 0,
      attachmentsCount: parsed.attachments?.length || 0,
    });
    
    // Clean the HTML content if it exists
    const cleanedHtml = parsed.html ? cleanHtml(parsed.html) : null;
    
    // Return a properly structured object with all fields explicitly specified
    return {
      subject: parsed.subject || null,
      from: getAddressText(parsed.from),
      to: getAddressText(parsed.to),
      cc: getAddressText(parsed.cc),
      bcc: getAddressText(parsed.bcc),
      date: parsed.date || null,
      html: cleanedHtml,
      text: parsed.text || null,
      attachments: parsed.attachments || [],
      headers: Object.fromEntries(parsed.headers)
    };
  } catch (error) {
    console.error('Error parsing email:', error);
    throw error;
  }
}