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

export async function GET(request: Request) {
  // Verify auth
  const session = await getServerSession(authOptions);
  if (!session?.user?.id) {
    return NextResponse.json(
      { error: 'Unauthorized' },
      { status: 401 }
    );
  }
  
  const { searchParams } = new URL(request.url);
  const accountId = searchParams.get('accountId');
  const userId = session.user.id;
  
  try {
    // If specific accountId is provided, get folders for that account
    if (accountId) {
      // Get account from database
      const account = await prisma.mailCredentials.findFirst({
        where: { 
          id: accountId,
          userId 
        },
        select: {
          email: true,
          password: true,
          host: true,
          port: true
        }
      });
      
      if (!account) {
        return NextResponse.json(
          { error: 'Account not found' },
          { status: 404 }
        );
      }
      
      // Connect to IMAP server for this account
      const client = new ImapFlow({
        host: account.host,
        port: account.port,
        secure: true,
        auth: {
          user: account.email,
          pass: account.password,
        },
        logger: false,
        tls: {
          rejectUnauthorized: false
        }
      });
      
      try {
        await client.connect();
        
        // Get folders for this account
        const folders = await getMailboxes(client);
        
        // Close connection
        await client.logout();
        
        return NextResponse.json({
          accountId,
          email: account.email,
          folders
        });
      } catch (error) {
        return NextResponse.json(
          { 
            error: 'Failed to connect to IMAP server',
            details: error instanceof Error ? error.message : 'Unknown error' 
          },
          { status: 500 }
        );
      }
    } else {
      // Get folders for all accounts
      const accounts = await prisma.mailCredentials.findMany({
        where: { userId },
        select: {
          id: true,
          email: true
        }
      });
      
      // For demo purposes, rather than connecting to all accounts, 
      // get the default set of folders from the first cached account
      const credentials = await getCachedEmailCredentials(userId);
      
      if (!credentials) {
        return NextResponse.json({
          accounts: accounts.map(account => ({
            id: account.id,
            email: account.email,
            folders: ['INBOX', 'Sent', 'Drafts', 'Trash'] // Fallback folders
          }))
        });
      }
      
      // 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,
        tls: {
          rejectUnauthorized: false
        }
      });
      
      try {
        await client.connect();
        
        // Get folders
        const folders = await getMailboxes(client);
        
        // Close connection
        await client.logout();
        
        return NextResponse.json({
          accounts: accounts.map(account => ({
            id: account.id,
            email: account.email,
            folders
          }))
        });
      } catch (error) {
        return NextResponse.json({
          accounts: accounts.map(account => ({
            id: account.id,
            email: account.email,
            folders: ['INBOX', 'Sent', 'Drafts', 'Trash'] // Fallback folders on error
          })),
          error: error instanceof Error ? error.message : 'Unknown error'
        });
      }
    }
  } catch (error) {
    return NextResponse.json(
      { 
        error: 'Failed to get account folders',
        details: error instanceof Error ? error.message : 'Unknown error' 
      },
      { status: 500 }
    );
  }
}