namespace App\Services;

use App\Models\Nominee;
use App\Models\Transaction;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;

class VoteService
{
/**
* Verify a Paystack reference server-side and, if successful,
* atomically credit votes + mark the transaction as paid.
* Idempotent: replayed webhooks/callbacks are safely ignored.
*/
public function verifyAndCredit(string $reference): Transaction
{
$tx = Transaction::where('paystack_reference', $reference)->firstOrFail();

if ($tx->status === 'success') {
return $tx; // already processed — no double-crediting
}

$response = Http::withToken(config('services.paystack.secretKey'))
->acceptJson()
->get(config('services.paystack.paymentUrl') . "/transaction/verify/{$reference}");

$data = $response->json('data') ?? [];
$paidAmount = (int) ($data['amount'] ?? 0); // kobo
$expected = (int) round($tx->amount_paid * 100); // kobo

if ($response->successful()
&& ($data['status'] ?? '') === 'success'
&& $paidAmount === $expected) {

DB::transaction(function () use ($tx) {
// Lock the row to prevent double-crediting races
$tx = Transaction::whereKey($tx->id)->lockForUpdate()->first();

if ($tx->status !== 'success') {
$tx->update(['status' => 'success', 'paid_at' => now()]);
Nominee::whereKey($tx->nominee_id)->increment('votes', $tx->vote_count);
}
});

$tx->refresh();
} else {
$tx->update(['status' => 'failed']);
Log::warning('Paystack verification failed', ['reference' => $reference, 'body' => $response->json()]);
}

return $tx;
}
}