feat(validation): add validators

ts/index.ts

@@ -9,7 +9,28 @@ import { XInvoiceDecoder } from './formats/xinvoice.decoder.js';
 import { DecoderFactory } from './formats/decoder.factory.js';
 import { BaseDecoder } from './formats/base.decoder.js';
 
-// Export interfaces
+// Import validator classes
+import { ValidatorFactory } from './formats/validator.factory.js';
+import { BaseValidator } from './formats/base.validator.js';
+import { FacturXValidator } from './formats/facturx.validator.js';
+import { UBLValidator } from './formats/ubl.validator.js';
+
+// Export specific interfaces for easier use
+export type {
+  IXInvoice,
+  IParty,
+  IAddress,
+  IContact,
+  IInvoiceItem,
+  ValidationError,
+  ValidationResult,
+  ValidationLevel,
+  InvoiceFormat,
+  XInvoiceOptions,
+  IValidator
+} from './interfaces.js';
+
+// Export interfaces (legacy support)
 export { interfaces };
 
 // Export main class
@@ -30,6 +51,47 @@ export {
   XInvoiceDecoder
 };
 
+// Export validator classes
+export const Validators = {
+  ValidatorFactory,
+  BaseValidator,
+  FacturXValidator,
+  UBLValidator
+};
+
 // For backward compatibility
 export { FacturXEncoder as ZugferdXmlEncoder };
-export { FacturXDecoder as ZUGFeRDXmlDecoder };
+export { FacturXDecoder as ZUGFeRDXmlDecoder };
+
+/**
+ * Validates an XML string against the appropriate format rules
+ * @param xml XML content to validate
+ * @param level Validation level (syntax, semantic, business)
+ * @returns ValidationResult with the result of validation
+ */
+export function validateXml(
+  xml: string, 
+  level: interfaces.ValidationLevel = interfaces.ValidationLevel.SYNTAX
+): interfaces.ValidationResult {
+  try {
+    const validator = ValidatorFactory.createValidator(xml);
+    return validator.validate(level);
+  } catch (error) {
+    return {
+      valid: false,
+      errors: [{
+        code: 'VAL-ERROR',
+        message: `Validation error: ${error.message}`
+      }],
+      level
+    };
+  }
+}
+
+/**
+ * Creates a new XInvoice instance
+ * @returns A new XInvoice instance
+ */
+export function createXInvoice(): XInvoice {
+  return new XInvoice();
+}