import { serve } from 'https://deno.land/std@0.168.0/http/server.ts';
import { createClient } from 'https://esm.sh/@supabase/supabase-js@2';
import Stripe from 'https://esm.sh/stripe@14?target=deno';

const stripe = new Stripe(Deno.env.get('STRIPE_SECRET_KEY')!, { apiVersion: '2023-10-16' });

const corsHeaders = {
  'Access-Control-Allow-Origin': '*',
  'Access-Control-Allow-Headers': 'authorization, x-client-info, apikey, content-type',
};

serve(async (req) => {
  if (req.method === 'OPTIONS') return new Response('ok', { headers: corsHeaders });

  const supabase = createClient(
    Deno.env.get('SUPABASE_URL')!,
    Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!,
  );

  // Find all paid invoices that don't have a stripe_fee yet
  const { data: invoices, error } = await supabase
    .from('invoices')
    .select('id, invoice_number, total')
    .eq('status', 'paid')
    .is('stripe_fee', null);

  if (error) {
    return new Response(JSON.stringify({ error: error.message }), { status: 500, headers: corsHeaders });
  }

  if (!invoices?.length) {
    return new Response(JSON.stringify({ message: 'No invoices missing fees', updated: 0 }), { headers: corsHeaders });
  }

  const results: { invoice_id: string; invoice_number: string; status: string; fee?: number }[] = [];

  for (const invoice of invoices) {
    try {
      // Search Stripe checkout sessions by invoice_id metadata
      const sessions = await stripe.checkout.sessions.search({
        query: `metadata["invoice_id"]:"${invoice.id}"`,
        limit: 1,
        expand: ['data.payment_intent.latest_charge.balance_transaction'],
      });

      const session = sessions.data[0];
      if (!session) {
        results.push({ invoice_id: invoice.id, invoice_number: invoice.invoice_number, status: 'no_session' });
        continue;
      }

      const paymentIntent = session.payment_intent as Stripe.PaymentIntent | null;
      const charge = paymentIntent?.latest_charge as Stripe.Charge | null;
      const balanceTx = charge?.balance_transaction as Stripe.BalanceTransaction | null;

      if (balanceTx?.fee == null) {
        results.push({ invoice_id: invoice.id, invoice_number: invoice.invoice_number, status: 'no_balance_tx' });
        continue;
      }

      const stripe_fee = balanceTx.fee / 100;
      await supabase.from('invoices').update({ stripe_fee }).eq('id', invoice.id);
      results.push({ invoice_id: invoice.id, invoice_number: invoice.invoice_number, status: 'updated', fee: stripe_fee });
    } catch (err) {
      results.push({ invoice_id: invoice.id, invoice_number: invoice.invoice_number, status: `error: ${err.message}` });
    }
  }

  const updated = results.filter(r => r.status === 'updated').length;
  return new Response(
    JSON.stringify({ updated, total: invoices.length, results }),
    { headers: { ...corsHeaders, 'Content-Type': 'application/json' } },
  );
});