Add pipeline module registries

internal/framework/pipeline/validator_registry.go

@@ -0,0 +1,102 @@
+package pipeline
+
+import (
+	"fmt"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+)
+
+type ValidatorConstructor func() (contracts.Validator, error)
+
+type ValidatorRegistry struct {
+	constructors map[string]ValidatorConstructor
+	specs        map[string]ModuleSpec
+}
+
+func NewValidatorRegistry() *ValidatorRegistry {
+	return &ValidatorRegistry{
+		constructors: make(map[string]ValidatorConstructor),
+		specs:        make(map[string]ModuleSpec),
+	}
+}
+
+func (r *ValidatorRegistry) Register(key string, constructor ValidatorConstructor) error {
+	return r.RegisterWithSpec(defaultModuleSpec(key, StageValidate), constructor)
+}
+
+func (r *ValidatorRegistry) RegisterWithSpec(spec ModuleSpec, constructor ValidatorConstructor) error {
+	if r == nil {
+		return fmt.Errorf("validator registry must not be nil")
+	}
+
+	normalizedSpec := normalizeModuleSpec(spec)
+	if err := validateModuleSpec("validator", StageValidate, normalizedSpec); err != nil {
+		return err
+	}
+	if constructor == nil {
+		return fmt.Errorf("validator constructor for %q must not be nil", normalizedSpec.Key)
+	}
+	if _, ok := r.constructors[normalizedSpec.Key]; ok {
+		return fmt.Errorf("validator %q is already registered", normalizedSpec.Key)
+	}
+
+	if r.constructors == nil {
+		r.constructors = make(map[string]ValidatorConstructor)
+	}
+	if r.specs == nil {
+		r.specs = make(map[string]ModuleSpec)
+	}
+	r.constructors[normalizedSpec.Key] = constructor
+	r.specs[normalizedSpec.Key] = cloneModuleSpec(normalizedSpec)
+	return nil
+}
+
+func (r *ValidatorRegistry) Build(key string) (contracts.Validator, error) {
+	if r == nil {
+		return nil, fmt.Errorf("validator registry must not be nil")
+	}
+
+	normalizedKey := strings.TrimSpace(key)
+	if normalizedKey == "" {
+		return nil, fmt.Errorf("validator key must not be empty")
+	}
+
+	constructor, ok := r.constructors[normalizedKey]
+	if !ok {
+		return nil, fmt.Errorf("validator %q is not registered", normalizedKey)
+	}
+
+	validator, err := constructor()
+	if err != nil {
+		return nil, fmt.Errorf("build validator %q: %w", normalizedKey, err)
+	}
+	if validator == nil {
+		return nil, fmt.Errorf("validator %q constructor returned nil", normalizedKey)
+	}
+	if validator.Name() != normalizedKey {
+		return nil, fmt.Errorf("validator %q returned name %q", normalizedKey, validator.Name())
+	}
+
+	return validator, nil
+}
+
+func (r *ValidatorRegistry) Spec(key string) (ModuleSpec, bool) {
+	if r == nil {
+		return ModuleSpec{}, false
+	}
+
+	spec, ok := r.specs[strings.TrimSpace(key)]
+	if !ok {
+		return ModuleSpec{}, false
+	}
+	return cloneModuleSpec(spec), true
+}
+
+func (r *ValidatorRegistry) RegisteredKeys() []string {
+	if r == nil {
+		return nil
+	}
+
+	return sortedRegistryKeys(r.constructors)
+}