Add frozen validation preparation plans

internal/validate/standard_validator.go

@@ -45,6 +45,101 @@ func (v *FSValidator) Validate(ctx context.Context, artifact *domain.Artifact, c
 	return validateArtifact(ctx, artifact, contract, v.validateJSONSchema)
 }
 
+type preparedValidation struct {
+	contract       domain.OutputContract
+	schemaDocument any
+	schema         *jsonschema.Schema
+}
+
+func (p *preparedValidation) Validate(ctx context.Context, artifact *domain.Artifact) (domain.ValidationResult, error) {
+	return validateArtifact(ctx, artifact, p.contract, p.validateJSONSchema)
+}
+
+func (p *preparedValidation) SchemaDocument() any {
+	return p.schemaDocument
+}
+
+func (p *preparedValidation) validateJSONSchema(instance any, _ string) ([]string, error) {
+	if p.schema == nil {
+		return nil, errors.New("prepared JSON schema is unavailable")
+	}
+	if err := p.schema.Validate(instance); err != nil {
+		return []string{fmt.Sprintf("json schema validation failed: %v", err)}, nil
+	}
+	return nil, nil
+}
+
+func (v *StandardValidator) PrepareValidation(ctx context.Context, contract domain.OutputContract) (PreparedValidation, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	prepared := &preparedValidation{contract: contract}
+	if contract.ValidationMode != domain.ValidationJSONSchema {
+		return prepared, nil
+	}
+
+	resolvedSchemaPath, err := v.resolveSchemaPath(contract.SchemaPath)
+	if err != nil {
+		return nil, err
+	}
+	schemaDocument, err := loadJSONSchemaFile(resolvedSchemaPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to compile JSON schema %q: %w", resolvedSchemaPath, err)
+	}
+	schemaRoot, err := v.schemaRoot()
+	if err != nil {
+		return nil, err
+	}
+	compiler := newSchemaCompiler(standardSchemaLoader{root: schemaRoot})
+	if err := compiler.AddResource(resolvedSchemaPath, schemaDocument); err != nil {
+		return nil, fmt.Errorf("failed to register JSON schema %q: %w", resolvedSchemaPath, err)
+	}
+	schema, err := compiler.Compile(resolvedSchemaPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to compile JSON schema %q: %w", resolvedSchemaPath, err)
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	prepared.schemaDocument = schemaDocument
+	prepared.schema = schema
+	return prepared, nil
+}
+
+func (v *FSValidator) PrepareValidation(ctx context.Context, contract domain.OutputContract) (PreparedValidation, error) {
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	prepared := &preparedValidation{contract: contract}
+	if contract.ValidationMode != domain.ValidationJSONSchema {
+		return prepared, nil
+	}
+
+	schemaName, schemaDocument, err := v.loadSchemaDocument(contract.SchemaPath)
+	if err != nil {
+		return nil, err
+	}
+	resourceURL := fsSchemaResourceURL(schemaName)
+	compiler := newSchemaCompiler(fsSchemaLoader{fsys: v.fsys, root: filecatalog.CleanFSRoot(v.root)})
+	if err := compiler.AddResource(resourceURL, schemaDocument); err != nil {
+		return nil, fmt.Errorf("failed to register JSON schema %q: %w", schemaName, err)
+	}
+	schema, err := compiler.Compile(resourceURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to compile JSON schema %q: %w", schemaName, err)
+	}
+	if err := ctx.Err(); err != nil {
+		return nil, err
+	}
+
+	prepared.schemaDocument = schemaDocument
+	prepared.schema = schema
+	return prepared, nil
+}
+
 type schemaValidatorFunc func(instance any, schemaPath string) ([]string, error)
 
 func validateArtifact(ctx context.Context, artifact *domain.Artifact, contract domain.OutputContract, validateSchema schemaValidatorFunc) (domain.ValidationResult, error) {