import { simpleParser } from 'mailparser';

export function cleanHtml(html: string): string {
  try {
    // More permissive cleaning that preserves styling but removes potentially harmful elements
    return html
      .replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '')
      .replace(/<iframe\b[^<]*(?:(?!<\/iframe>)<[^<]*)*<\/iframe>/gi, '')
      .replace(/<object\b[^<]*(?:(?!<\/object>)<[^<]*)*<\/object>/gi, '')
      .replace(/<embed\b[^<]*(?:(?!<\/embed>)<[^<]*)*<\/embed>/gi, '')
      .replace(/<form\b[^<]*(?:(?!<\/form>)<[^<]*)*<\/form>/gi, '')
      .replace(/on\w+="[^"]*"/gi, '') // Remove inline event handlers (onclick, onload, etc.)
      .replace(/on\w+='[^']*'/gi, '');
  } 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;
  }
}