Sub2API v1.0 - AI API 网关（二开初始版本，基于上游 Wei-Shaw/sub2api）

backend/internal/service/payment_webhook_provider.go

@@ -0,0 +1,148 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"strings"
+
+	dbent "github.com/Wei-Shaw/sub2api/ent"
+	"github.com/Wei-Shaw/sub2api/ent/paymentorder"
+	"github.com/Wei-Shaw/sub2api/ent/paymentproviderinstance"
+	"github.com/Wei-Shaw/sub2api/internal/payment"
+)
+
+// GetWebhookProvider returns the provider instance that should verify a webhook.
+// It resolves the original provider instance from the order whenever possible and
+// only falls back to a registry provider for legacy/single-instance scenarios.
+func (s *PaymentService) GetWebhookProvider(ctx context.Context, providerKey, outTradeNo string) (payment.Provider, error) {
+	providers, err := s.GetWebhookProviders(ctx, providerKey, outTradeNo)
+	if err != nil {
+		return nil, err
+	}
+	if len(providers) == 0 {
+		return nil, payment.ErrProviderNotFound
+	}
+	return providers[0], nil
+}
+
+// GetWebhookProviders returns provider candidates that can verify the webhook.
+// Official WeChat Pay may require multiple candidates because the callback body
+// cannot be bound to a merchant before decryption.
+func (s *PaymentService) GetWebhookProviders(ctx context.Context, providerKey, outTradeNo string) ([]payment.Provider, error) {
+	if outTradeNo != "" {
+		order, err := s.entClient.PaymentOrder.Query().Where(paymentorder.OutTradeNo(outTradeNo)).Only(ctx)
+		if err == nil {
+			if psHasPinnedProviderInstance(order) {
+				prov, err := s.getPinnedOrderProvider(ctx, order)
+				if err != nil {
+					return nil, err
+				}
+				return []payment.Provider{prov}, nil
+			}
+			inst, err := s.getOrderProviderInstance(ctx, order)
+			if err != nil {
+				return nil, fmt.Errorf("load order provider instance: %w", err)
+			}
+			if inst != nil {
+				prov, err := s.createProviderFromInstance(ctx, inst)
+				if err != nil {
+					return nil, err
+				}
+				return []payment.Provider{prov}, nil
+			}
+			if strings.TrimSpace(providerKey) == payment.TypeWxpay {
+				return s.getEnabledWebhookProvidersByKey(ctx, providerKey)
+			}
+			if !s.webhookRegistryFallbackAllowed(ctx, providerKey) {
+				return nil, fmt.Errorf("webhook provider fallback is ambiguous for %s", providerKey)
+			}
+			s.EnsureProviders(ctx)
+			prov, err := s.registry.GetProviderByKey(providerKey)
+			if err != nil {
+				return nil, err
+			}
+			return []payment.Provider{prov}, nil
+		}
+	}
+
+	if strings.TrimSpace(providerKey) == payment.TypeWxpay {
+		return s.getEnabledWebhookProvidersByKey(ctx, providerKey)
+	}
+
+	if !s.webhookRegistryFallbackAllowed(ctx, providerKey) {
+		return nil, fmt.Errorf("webhook provider fallback is ambiguous for %s", providerKey)
+	}
+
+	s.EnsureProviders(ctx)
+	prov, err := s.registry.GetProviderByKey(providerKey)
+	if err != nil {
+		return nil, err
+	}
+	return []payment.Provider{prov}, nil
+}
+
+func (s *PaymentService) getPinnedOrderProvider(ctx context.Context, o *dbent.PaymentOrder) (payment.Provider, error) {
+	inst, err := s.getOrderProviderInstance(ctx, o)
+	if err != nil {
+		return nil, fmt.Errorf("load order provider instance: %w", err)
+	}
+	if inst == nil {
+		return nil, fmt.Errorf("order %d provider instance is missing", o.ID)
+	}
+	return s.createProviderFromInstance(ctx, inst)
+}
+
+func (s *PaymentService) webhookRegistryFallbackAllowed(ctx context.Context, providerKey string) bool {
+	providerKey = strings.TrimSpace(providerKey)
+	if providerKey == "" || s == nil || s.entClient == nil {
+		return false
+	}
+
+	count, err := s.entClient.PaymentProviderInstance.Query().
+		Where(
+			paymentproviderinstance.ProviderKeyEQ(providerKey),
+			paymentproviderinstance.EnabledEQ(true),
+		).
+		Count(ctx)
+	if err != nil {
+		slog.Warn("payment webhook fallback instance count failed", "provider", providerKey, "error", err)
+		return false
+	}
+	return count <= 1
+}
+
+func psHasPinnedProviderInstance(order *dbent.PaymentOrder) bool {
+	return order != nil && (psOrderProviderSnapshot(order) != nil || (order.ProviderInstanceID != nil && strings.TrimSpace(*order.ProviderInstanceID) != ""))
+}
+
+func (s *PaymentService) getEnabledWebhookProvidersByKey(ctx context.Context, providerKey string) ([]payment.Provider, error) {
+	providerKey = strings.TrimSpace(providerKey)
+	instances, err := s.entClient.PaymentProviderInstance.Query().
+		Where(
+			paymentproviderinstance.ProviderKeyEQ(providerKey),
+			paymentproviderinstance.EnabledEQ(true),
+		).
+		Order(dbent.Asc(paymentproviderinstance.FieldSortOrder)).
+		All(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("query webhook provider instances: %w", err)
+	}
+	if len(instances) == 0 {
+		return nil, payment.ErrProviderNotFound
+	}
+
+	providers := make([]payment.Provider, 0, len(instances))
+	for _, inst := range instances {
+		prov, provErr := s.createProviderFromInstance(ctx, inst)
+		if provErr != nil {
+			slog.Warn("skip webhook provider instance", "provider", providerKey, "instanceID", inst.ID, "error", provErr)
+			continue
+		}
+		providers = append(providers, prov)
+	}
+	if len(providers) == 0 {
+		return nil, payment.ErrProviderNotFound
+	}
+	return providers, nil
+}