import { simpleParser } from 'mailparser';
import DOMPurify from 'isomorphic-dompurify';

function cleanHtml(html: string): string {
  try {
    return DOMPurify.sanitize(html, {
      ALLOWED_TAGS: ['p', 'br', 'div', 'span', 'a', 'img', 'strong', 'em', 'u', 'ul', 'ol', 'li', 'blockquote', 'pre', 'code', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6'],
      ALLOWED_ATTR: ['href', 'src', 'alt', 'title', 'class', 'style'],
      ALLOWED_URI_REGEXP: /^(?:(?:(?:f|ht)tps?|mailto|tel):|[^a-z]|[a-z+.\-]+(?:[^a-z+.\-:]|$))/i
    });
  } 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 {
    const parsed = await simpleParser(emailContent);
    
    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: parsed.html ? cleanHtml(parsed.html) : null,
      text: parsed.text || null,
      attachments: parsed.attachments || [],
      headers: Object.fromEntries(parsed.headers)
    };
  } catch (error) {
    console.error('Error parsing email:', error);
    throw error;
  }
}