import { BaseEncoder } from '../base/base.encoder.js';
import type { TInvoice, TCreditNote, TDebitNote } from '../../interfaces/common.js';
import { UBLDocumentType, UBL_NAMESPACES } from './ubl.types.js';

/**
 * Base encoder for UBL-based invoice formats
 */
export abstract class UBLBaseEncoder extends BaseEncoder {
  /**
   * Encodes a TInvoice object into UBL XML
   * @param invoice TInvoice object to encode
   * @returns UBL XML string
   */
  public async encode(invoice: TInvoice): Promise<string> {
    // TInvoice is always an invoice, treat it as debit note for encoding
    return this.encodeDebitNote(invoice as unknown as TDebitNote);
  }

  /**
   * Encodes a TCreditNote object into UBL XML
   * @param creditNote TCreditNote object to encode
   * @returns UBL XML string
   */
  protected abstract encodeCreditNote(creditNote: TCreditNote): Promise<string>;

  /**
   * Encodes a TDebitNote object into UBL XML
   * @param debitNote TDebitNote object to encode
   * @returns UBL XML string
   */
  protected abstract encodeDebitNote(debitNote: TDebitNote): Promise<string>;

  /**
   * Creates the XML declaration and root element
   * @param documentType UBL document type
   * @returns XML string with declaration and root element
   */
  protected createXmlRoot(documentType: UBLDocumentType): string {
    return `<?xml version="1.0" encoding="UTF-8"?>
<${documentType} xmlns="urn:oasis:names:specification:ubl:schema:xsd:${documentType}-2"
  xmlns:cac="${UBL_NAMESPACES.CAC}"
  xmlns:cbc="${UBL_NAMESPACES.CBC}">
</${documentType}>`;
  }

  /**
   * Formats a date as an ISO string (YYYY-MM-DD)
   * @param timestamp Timestamp to format
   * @returns Formatted date string
   */
  protected formatDate(timestamp: number): string {
    // Ensure timestamp is valid
    if (!timestamp || isNaN(timestamp)) {
      timestamp = Date.now();
    }
    const date = new Date(timestamp);
    // Check if date is valid
    if (isNaN(date.getTime())) {
      return new Date().toISOString().split('T')[0];
    }
    return date.toISOString().split('T')[0];
  }
}