import { NextResponse } from 'next/server';
import { ImapFlow } from 'imapflow';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';
import { prisma } from '@/lib/prisma';

// Get the email list cache from main API route
// This is a hack - ideally we'd use a shared module or Redis for caching
declare global {
  var emailListCache: { [key: string]: { data: any, timestamp: number } };
}

// Helper function to invalidate cache for a specific folder
const invalidateCache = (userId: string, folder?: string) => {
  if (!global.emailListCache) return;
  
  Object.keys(global.emailListCache).forEach(key => {
    // If folder is provided, only invalidate that folder's cache
    if (folder) {
      if (key.includes(`${userId}:${folder}`)) {
        delete global.emailListCache[key];
      }
    } else {
      // Otherwise invalidate all user's caches
      if (key.startsWith(`${userId}:`)) {
        delete global.emailListCache[key];
      }
    }
  });
};

// Mark email as read
export async function POST(
  request: Request,
  { params }: { params: { id: string } }
) {
  try {
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const emailId = params.id;
    if (!emailId) {
      return NextResponse.json({ error: 'Email ID is required' }, { status: 400 });
    }

    // Get credentials from database
    const credentials = await prisma.mailCredentials.findUnique({
      where: { userId: session.user.id },
    });

    if (!credentials) {
      return NextResponse.json({ error: 'No mail credentials found' }, { status: 401 });
    }

    // Connect to IMAP server
    const client = new ImapFlow({
      host: credentials.host,
      port: credentials.port,
      secure: true,
      auth: {
        user: credentials.email,
        pass: credentials.password,
      },
      logger: false,
      emitLogs: false,
      tls: {
        rejectUnauthorized: false
      }
    });

    try {
      await client.connect();
      
      // Find which folder contains this email
      const mailboxes = await client.list();
      let emailFolder = 'INBOX'; // Default to INBOX
      let foundEmail = false;
      
      // Search through folders to find the email
      for (const box of mailboxes) {
        try {
          await client.mailboxOpen(box.path);
          
          // Search for the email by UID
          const message = await client.fetchOne(emailId, { flags: true });
          if (message) {
            emailFolder = box.path;
            foundEmail = true;
            
            // Mark as read if not already
            if (!message.flags.has('\\Seen')) {
              await client.messageFlagsAdd(emailId, ['\\Seen']);
            }
            break;
          }
        } catch (error) {
          console.log(`Error searching in folder ${box.path}:`, error);
          // Continue with next folder
        }
      }

      if (!foundEmail) {
        return NextResponse.json(
          { error: 'Email not found' },
          { status: 404 }
        );
      }
      
      // Invalidate the cache for this folder
      invalidateCache(session.user.id, emailFolder);

      return NextResponse.json({ success: true });
    } finally {
      try {
        await client.logout();
      } catch (e) {
        console.error('Error during logout:', e);
      }
    }
  } catch (error) {
    console.error('Error marking email as read:', error);
    return NextResponse.json(
      { error: 'Failed to mark email as read' },
      { status: 500 }
    );
  }
}