import { NextRequest, NextResponse } from 'next/server';
import { cookies } from 'next/headers';
import { stripe } from '@/lib/stripe';
import { db } from '@/lib/db';
import { rateLimit, getClientIdentifier, RateLimits } from '@/lib/rateLimit';

export async function POST(request: NextRequest) {
  try {
    const userId = cookies().get('userId')?.value;

    // Rate Limiting (user-based)
    const clientId = userId || getClientIdentifier(request);
    const rateLimitResult = rateLimit(clientId, RateLimits.STRIPE_PORTAL);

    if (!rateLimitResult.success) {
      return NextResponse.json(
        {
          error: 'Too many requests. Please try again later.',
          retryAfter: Math.ceil((rateLimitResult.reset - Date.now()) / 1000)
        },
        {
          status: 429,
          headers: {
            'X-RateLimit-Limit': rateLimitResult.limit.toString(),
            'X-RateLimit-Remaining': rateLimitResult.remaining.toString(),
            'X-RateLimit-Reset': rateLimitResult.reset.toString(),
          }
        }
      );
    }
    if (!userId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    // Get user with Stripe customer ID
    const user = await db.user.findUnique({
      where: { id: userId },
      select: {
        stripeCustomerId: true,
        email: true,
      },
    });

    if (!user) {
      return NextResponse.json({ error: 'User not found' }, { status: 404 });
    }

    // If user doesn't have a Stripe customer ID, they can't access the portal
    if (!user.stripeCustomerId) {
      return NextResponse.json(
        { error: 'No active subscription found' },
        { status: 400 }
      );
    }

    // Create Stripe Customer Portal session
    const portalSession = await stripe.billingPortal.sessions.create({
      customer: user.stripeCustomerId,
      return_url: `${process.env.NEXT_PUBLIC_APP_URL || 'http://localhost:3000'}/settings`,
    });

    return NextResponse.json({ url: portalSession.url });
  } catch (error) {
    console.error('Error creating portal session:', error);
    return NextResponse.json(
      { error: 'Failed to create portal session' },
      { status: 500 }
    );
  }
}
