import { NextResponse } from 'next/server';
import { simpleParser, AddressObject } from 'mailparser';

function getEmailAddress(address: AddressObject | AddressObject[] | undefined): string | null {
  if (!address) return null;
  if (Array.isArray(address)) {
    return address.map(a => a.text).join(', ');
  }
  return address.text;
}

// Clean up the HTML to make it safe but preserve styles
function processHtml(html: string | null): string | null {
  if (!html) return null;
  
  try {
    // Make the content display well in the email context
    return html
      // Fix self-closing tags that might break React
      .replace(/<(br|hr|img|input|link|meta|area|base|col|embed|keygen|param|source|track|wbr)([^>]*)>/gi, '<$1$2 />')
      // Keep style tags but ensure they're closed properly
      .replace(/<style([^>]*)>([\s\S]*?)<\/style>/gi, (match) => {
        // Just return the matched style tag as-is
        return match;
      });
  } catch (error) {
    console.error('Error processing HTML:', error);
    return html;
  }
}

export async function POST(request: Request) {
  try {
    const body = await request.json();
    const { email } = body;
    
    if (!email || typeof email !== 'string') {
      return NextResponse.json(
        { error: 'Invalid email content' },
        { status: 400 }
      );
    }

    const parsed = await simpleParser(email);
    
    // Process the HTML to preserve styling but make it safe
    // Handle the case where parsed.html could be a boolean
    const processedHtml = typeof parsed.html === 'string' ? processHtml(parsed.html) : null;
    
    return NextResponse.json({
      subject: parsed.subject || null,
      from: getEmailAddress(parsed.from),
      to: getEmailAddress(parsed.to),
      cc: getEmailAddress(parsed.cc),
      bcc: getEmailAddress(parsed.bcc),
      date: parsed.date || null,
      html: processedHtml,
      text: parsed.textAsHtml || parsed.text || null,
      attachments: parsed.attachments?.map(att => ({
        filename: att.filename,
        contentType: att.contentType,
        size: att.size
      })) || [],
      headers: parsed.headers || {}
    });
  } catch (error) {
    console.error('Error parsing email:', error);
    return NextResponse.json(
      { error: 'Failed to parse email' },
      { status: 500 }
    );
  }
}