import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';
import { markEmailReadStatus } from '@/lib/services/email-service';

// Global cache reference (will be moved to a proper cache solution in the future)
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 {
    // Get session
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    // No need to await Promise.resolve(), params is already an object
    const { id: emailId } = params;
    if (!emailId) {
      return NextResponse.json({ error: 'Email ID is required' }, { status: 400 });
    }

    try {
      // Use the email service to mark the email as read
      // First try with INBOX folder
      let success = await markEmailReadStatus(session.user.id, emailId, true, 'INBOX');
      
      // If not found in INBOX, try to find it in other common folders
      if (!success) {
        const commonFolders = ['Sent', 'Drafts', 'Trash', 'Spam', 'Junk'];
        
        for (const folder of commonFolders) {
          success = await markEmailReadStatus(session.user.id, emailId, true, folder);
          if (success) {
            // If found in a different folder, invalidate that folder's cache
            invalidateCache(session.user.id, folder);
            break;
          }
        }
      } else {
        // Email found in INBOX, invalidate INBOX cache
        invalidateCache(session.user.id, 'INBOX');
      }
      
      if (!success) {
        return NextResponse.json(
          { error: 'Email not found in any folder' },
          { status: 404 }
        );
      }

      return NextResponse.json({ success: true });
    } catch (error) {
      console.error('Error marking email as read:', error);
      return NextResponse.json(
        { error: 'Failed to mark email as read' },
        { status: 500 }
      );
    }
  } catch (error) {
    console.error('Error marking email as read:', error);
    return NextResponse.json(
      { error: 'Failed to mark email as read' },
      { status: 500 }
    );
  }
}