writekit/internal/billing/billing_test.go

package billing

import (
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"testing"
)

func TestVerifyWebhook(t *testing.T) {
	secret := "test-webhook-secret"
	client := &LemonClient{webhookSecret: secret}

	t.Run("valid signature", func(t *testing.T) {
		payload := []byte(`{"meta":{"event_name":"subscription_created"}}`)

		mac := hmac.New(sha256.New, []byte(secret))
		mac.Write(payload)
		signature := hex.EncodeToString(mac.Sum(nil))

		if !client.VerifyWebhook(payload, signature) {
			t.Error("expected valid signature to pass verification")
		}
	})

	t.Run("invalid signature", func(t *testing.T) {
		payload := []byte(`{"meta":{"event_name":"subscription_created"}}`)
		signature := "invalid-signature"

		if client.VerifyWebhook(payload, signature) {
			t.Error("expected invalid signature to fail verification")
		}
	})

	t.Run("wrong secret", func(t *testing.T) {
		payload := []byte(`{"meta":{"event_name":"subscription_created"}}`)

		mac := hmac.New(sha256.New, []byte("different-secret"))
		mac.Write(payload)
		signature := hex.EncodeToString(mac.Sum(nil))

		if client.VerifyWebhook(payload, signature) {
			t.Error("expected signature with wrong secret to fail")
		}
	})

	t.Run("empty secret", func(t *testing.T) {
		clientNoSecret := &LemonClient{webhookSecret: ""}
		payload := []byte(`{"test": true}`)

		if clientNoSecret.VerifyWebhook(payload, "any-signature") {
			t.Error("expected empty secret to fail verification")
		}
	})

	t.Run("empty payload", func(t *testing.T) {
		payload := []byte{}

		mac := hmac.New(sha256.New, []byte(secret))
		mac.Write(payload)
		signature := hex.EncodeToString(mac.Sum(nil))

		if !client.VerifyWebhook(payload, signature) {
			t.Error("expected empty payload with valid signature to pass")
		}
	})
}

func TestNormalizeStatus(t *testing.T) {
	tests := []struct {
		input    string
		expected string
	}{
		{"on_trial", "active"},
		{"active", "active"},
		{"paused", "past_due"},
		{"past_due", "past_due"},
		{"unpaid", "past_due"},
		{"cancelled", "cancelled"},
		{"expired", "cancelled"},
		{"unknown_status", "unknown_status"},
	}

	for _, tt := range tests {
		t.Run(tt.input, func(t *testing.T) {
			got := normalizeStatus(tt.input)
			if got != tt.expected {
				t.Errorf("normalizeStatus(%q) = %q, want %q", tt.input, got, tt.expected)
			}
		})
	}
}

func TestParseWebhookEvent(t *testing.T) {
	client := &LemonClient{}

	t.Run("valid event", func(t *testing.T) {
		payload := []byte(`{
			"meta": {
				"event_name": "subscription_created",
				"custom_data": {"tenant_id": "tenant-123", "user_id": "user-456"}
			},
			"data": {"id": "sub-789"}
		}`)

		event, err := client.ParseWebhookEvent(payload)
		if err != nil {
			t.Fatalf("unexpected error: %v", err)
		}

		if event.Meta.EventName != "subscription_created" {
			t.Errorf("EventName = %q, want %q", event.Meta.EventName, "subscription_created")
		}

		if event.Meta.CustomData["tenant_id"] != "tenant-123" {
			t.Errorf("tenant_id = %q, want %q", event.Meta.CustomData["tenant_id"], "tenant-123")
		}
	})

	t.Run("invalid JSON", func(t *testing.T) {
		payload := []byte(`{invalid json}`)

		_, err := client.ParseWebhookEvent(payload)
		if err == nil {
			t.Error("expected error for invalid JSON")
		}
	})
}

func TestGetSubscriptionData(t *testing.T) {
	event := &WebhookEvent{
		Data: []byte(`{
			"id": "sub-123",
			"attributes": {
				"customer_id": 456,
				"variant_name": "Pro Monthly",
				"user_email": "test@example.com",
				"status": "active"
			}
		}`),
	}

	data, err := event.GetSubscriptionData()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if data.ID != "sub-123" {
		t.Errorf("ID = %q, want %q", data.ID, "sub-123")
	}

	if data.Attributes.CustomerID != 456 {
		t.Errorf("CustomerID = %d, want %d", data.Attributes.CustomerID, 456)
	}

	if data.Attributes.Status != "active" {
		t.Errorf("Status = %q, want %q", data.Attributes.Status, "active")
	}
}

func TestGetOrderData(t *testing.T) {
	event := &WebhookEvent{
		Data: []byte(`{
			"id": "order-123",
			"attributes": {
				"user_name": "John Doe",
				"user_email": "john@example.com",
				"total_usd": 500
			}
		}`),
	}

	data, err := event.GetOrderData()
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}

	if data.ID != "order-123" {
		t.Errorf("ID = %q, want %q", data.ID, "order-123")
	}

	if data.Attributes.TotalUsd != 500 {
		t.Errorf("TotalUsd = %d, want %d", data.Attributes.TotalUsd, 500)
	}
}