Add app backend factory wiring

internal/app/backends.go

@@ -0,0 +1,45 @@
+package app
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.maximumdirect.net/eric/distributor/internal/adapters/local"
+	"gitea.maximumdirect.net/eric/distributor/internal/config"
+	"gitea.maximumdirect.net/eric/distributor/internal/storage"
+)
+
+const storagePathKey = "path"
+
+type backendFactory struct {
+	registry *storage.Registry
+}
+
+func newBackendFactory() *backendFactory {
+	registry := storage.NewRegistry()
+	_ = registry.Register(config.BackendLocal, func(ctx context.Context, cfg storage.OpenConfig) (storage.Backend, error) {
+		if err := ctx.Err(); err != nil {
+			return nil, err
+		}
+		return local.New(cfg[storagePathKey])
+	})
+	return &backendFactory{registry: registry}
+}
+
+func (f *backendFactory) openSource(ctx context.Context, source config.Backend) (storage.Backend, error) {
+	if source.Backend != config.BackendLocal {
+		return nil, fmt.Errorf("source backend %s is not implemented for execution", source.Backend)
+	}
+	return f.registry.Open(ctx, source.Backend, storage.OpenConfig{storagePathKey: source.Path})
+}
+
+func (f *backendFactory) openDestination(ctx context.Context, destination config.Destination) (storage.Backend, error) {
+	if destination.Backend != config.BackendLocal {
+		return nil, fmt.Errorf("backend %s is not implemented for execution", destination.Backend)
+	}
+	return f.registry.Open(ctx, destination.Backend, storage.OpenConfig{storagePathKey: destination.Path})
+}
+
+func (f *backendFactory) openLocalPath(ctx context.Context, path string) (storage.Backend, error) {
+	return f.registry.Open(ctx, config.BackendLocal, storage.OpenConfig{storagePathKey: path})
+}