feat: reconcile Agones allocations durably

server/allocator/service.go

@@ -0,0 +1,46 @@
+// Package allocator coordinates provider allocation with durable control-plane
+// state. It does not expose an endpoint until both boundaries succeed.
+package allocator
+
+import (
+	"context"
+	"time"
+
+	"github.com/cosmic-clash/cosmic-clash/server/agones"
+	"github.com/cosmic-clash/cosmic-clash/server/domain"
+)
+
+type Provider interface {
+	Allocate(context.Context, domain.AllocationRequest, map[string]string, time.Time) (agones.AllocatedServer, error)
+}
+
+type Durable interface {
+	RecordProviderAllocation(context.Context, domain.Allocation, time.Time) (domain.Allocation, error)
+}
+
+type Service struct {
+	Provider Provider
+	Durable  Durable
+	Now      func() time.Time
+}
+
+func (s Service) Allocate(ctx context.Context, request domain.AllocationRequest, labels map[string]string) (agones.AllocatedServer, error) {
+	if s.Provider == nil || s.Durable == nil || s.Now == nil {
+		return agones.AllocatedServer{}, errNotConfigured
+	}
+	now := s.Now()
+	result, err := s.Provider.Allocate(ctx, request, labels, now)
+	if err != nil {
+		return agones.AllocatedServer{}, err
+	}
+	if _, err := s.Durable.RecordProviderAllocation(ctx, result.Allocation, now); err != nil {
+		return agones.AllocatedServer{}, err
+	}
+	return result, nil
+}
+
+var errNotConfigured = &configurationError{}
+
+type configurationError struct{}
+
+func (*configurationError) Error() string { return "allocator service is not configured" }