Fix Paddle coupon payload

app/Services/Paddle/PaddleDiscountService.php

@@ -88,19 +88,17 @@ class PaddleDiscountService
     protected function buildDiscountPayload(Coupon $coupon): array
     {
         $payload = [
-            'name' => $coupon->name,
             'code' => $coupon->code,
             'type' => $this->mapType($coupon->type),
             'amount' => $this->formatAmount($coupon),
-            'currency_code' => $coupon->currency ?? config('app.currency', 'EUR'),
+            'currency_code' => Str::upper((string) ($coupon->currency ?? config('app.currency', 'EUR'))),
             'enabled_for_checkout' => $coupon->enabled_for_checkout,
-            'description' => $coupon->description,
+            'description' => $this->resolveDescription($coupon),
             'mode' => $coupon->paddle_mode ?? 'standard',
             'usage_limit' => $coupon->usage_limit,
             'maximum_recurring_intervals' => null,
             'recur' => false,
             'restrict_to' => $this->resolveRestrictions($coupon),
-            'starts_at' => optional($coupon->starts_at)?->toIso8601String(),
             'expires_at' => optional($coupon->ends_at)?->toIso8601String(),
         ];
 
@@ -146,4 +144,27 @@ class PaddleDiscountService
 
         return $prices->isEmpty() ? null : $prices->all();
     }
+
+    protected function resolveDescription(Coupon $coupon): string
+    {
+        $description = trim((string) ($coupon->description ?? ''));
+
+        if ($description !== '') {
+            return $description;
+        }
+
+        $name = trim((string) ($coupon->name ?? ''));
+
+        if ($name !== '') {
+            return $name;
+        }
+
+        $code = trim((string) ($coupon->code ?? ''));
+
+        if ($code !== '') {
+            return sprintf('Coupon %s', $code);
+        }
+
+        return sprintf('Coupon %d', $coupon->id);
+    }
 }

tests/Unit/PaddleDiscountServiceTest.php

@@ -0,0 +1,88 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Enums\CouponType;
+use App\Models\Coupon;
+use App\Services\Paddle\PaddleClient;
+use App\Services\Paddle\PaddleDiscountService;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Mockery;
+use Tests\TestCase;
+
+class PaddleDiscountServiceTest extends TestCase
+{
+    use RefreshDatabase;
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+
+        Mockery::close();
+    }
+
+    public function test_build_payload_uses_description_fallback_and_excludes_name_and_starts_at(): void
+    {
+        $coupon = Coupon::factory()->create([
+            'name' => 'Launch Discount',
+            'description' => null,
+            'starts_at' => now()->subDay(),
+            'ends_at' => now()->addWeek(),
+            'type' => CouponType::PERCENTAGE,
+            'amount' => 10,
+        ]);
+
+        $service = new TestablePaddleDiscountService(Mockery::mock(PaddleClient::class));
+
+        $payload = $service->buildPayload($coupon);
+
+        $this->assertSame('Launch Discount', $payload['description']);
+        $this->assertArrayNotHasKey('name', $payload);
+        $this->assertArrayNotHasKey('starts_at', $payload);
+    }
+
+    public function test_build_payload_formats_flat_discount_amount_and_currency(): void
+    {
+        $coupon = Coupon::factory()->create([
+            'type' => CouponType::FLAT,
+            'amount' => 25.50,
+            'currency' => 'eur',
+            'description' => 'Flat discount',
+        ]);
+
+        $service = new TestablePaddleDiscountService(Mockery::mock(PaddleClient::class));
+
+        $payload = $service->buildPayload($coupon);
+
+        $this->assertSame('2550', $payload['amount']);
+        $this->assertSame('EUR', $payload['currency_code']);
+    }
+
+    public function test_build_payload_removes_currency_for_percentage_discounts(): void
+    {
+        $coupon = Coupon::factory()->create([
+            'type' => CouponType::PERCENTAGE,
+            'amount' => 15,
+            'currency' => 'EUR',
+            'description' => 'Percent discount',
+        ]);
+
+        $service = new TestablePaddleDiscountService(Mockery::mock(PaddleClient::class));
+
+        $payload = $service->buildPayload($coupon);
+
+        $this->assertSame('15.00', $payload['amount']);
+        $this->assertArrayNotHasKey('currency_code', $payload);
+    }
+}
+
+class TestablePaddleDiscountService extends PaddleDiscountService
+{
+    /**
+     * @return array<string, mixed>
+     */
+    public function buildPayload(Coupon $coupon): array
+    {
+        return $this->buildDiscountPayload($coupon);
+    }
+}