<?php
/* Copyright (C) 2024 Alex Vives Alcazar <avives@nubenet.digital>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <https://www.gnu.org/licenses/>.
 */

/**
 * \file       cfdixml/class/cfdi/CadenaOriginalBuilder.php
 * \ingroup    cfdixml
 * \brief      Clase para generar la cadena original del CFDI usando XSLT
 */
class CadenaOriginalBuilder
{
	private $xsltPath;
	private $xsltDoc;
	private $xsltProcessor;

	public function __construct($xsltPath)
	{
		$this->xsltPath = $xsltPath;
		$this->initializeXSLT();
	}


	/**
	 * Initializes the XSLT processor and loads the XSLT stylesheet.
	 *
	 * This method sets up the DOMDocument for the XSLT file, loads the XSLT from the specified path,
	 * creates an XSLTProcessor, and imports the stylesheet. It handles potential errors during the process.
	 *
	 * @throws \Exception If there's an error loading the XSLT file or importing the stylesheet.
	 * @return void
	 */
	private function initializeXSLT()
    {
        try {
            // Verificar si el archivo es remoto o local
            if (filter_var($this->xsltPath, FILTER_VALIDATE_URL)) {
                // Si es una URL, descargamos el contenido
                $context = stream_context_create([
                    'ssl' => [
                        'verify_peer' => false,
                        'verify_peer_name' => false,
                    ]
                ]);
                $xsltContent = file_get_contents($this->xsltPath, false, $context);

                // Modificar la versión del XSLT de 2.0 a 1.0
                $xsltContent = preg_replace('/version="2.0"/', 'version="1.0"', $xsltContent);

                // Crear documento temporal
                $this->xsltDoc = new \DOMDocument();
                $this->xsltDoc->loadXML($xsltContent);
            } else {
                // Si es local, cargar directamente
                $this->xsltDoc = new \DOMDocument();
                $xsltContent = file_get_contents($this->xsltPath);
                $xsltContent = preg_replace('/version="2.0"/', 'version="1.0"', $xsltContent);
                $this->xsltDoc->loadXML($xsltContent);
            }

            // Crear el procesador XSLT
            $this->xsltProcessor = new \XSLTProcessor();

            // Suprimir warnings durante la importación
            libxml_use_internal_errors(true);
            $imported = $this->xsltProcessor->importStylesheet($this->xsltDoc);
            libxml_use_internal_errors(false);

            if (!$imported) {
                throw new \Exception("No se pudo importar la hoja de estilos XSLT");
            }
        } catch (\Exception $e) {
            throw new \Exception("Error al inicializar XSLT: " . $e->getMessage());
        }
    }


	/**
	 * Builds the "Cadena Original" from an XML string using XSLT transformation.
	 *
	 * This function takes an XML string, transforms it using the initialized XSLT processor,
	 * and then cleans the resulting string to create the final "Cadena Original".
	 *
	 * @param string $xmlString The XML string to be transformed.
	 * @throws \Exception If there's an error during the XSLT transformation process.
	 * @return string The resulting "Cadena Original" after transformation and cleaning.
	 */
	public function buildCadenaOriginal($xmlString)
	{
		try {
			// Crear documento DOM del XML
			$xmlDoc = new \DOMDocument();
			$xmlDoc->loadXML($xmlString);

			// Realizar la transformación
			$cadenaOriginal = $this->xsltProcessor->transformToXml($xmlDoc);

			// Limpiar la cadena original
			$cadenaOriginal = $this->limpiarCadenaOriginal($cadenaOriginal);

			return $cadenaOriginal;
		} catch (\Exception $e) {
			throw new \Exception("Error en la transformación XSLT: " . $e->getMessage());
		}
	}

	/**
	 * Cleans and formats the "Cadena Original" string.
	 *
	 * This function removes unwanted characters, trims excess whitespace,
	 * and ensures the string starts and ends with '||' as required for
	 * a valid "Cadena Original" format.
	 *
	 * @param string $cadenaOriginal The raw "Cadena Original" string to be cleaned.
	 * @return string The cleaned and properly formatted "Cadena Original" string.
	 */
	private function limpiarCadenaOriginal($cadenaOriginal)
	{
		// Eliminar caracteres no deseados y espacios extras
		$cadenaOriginal = trim($cadenaOriginal);
		$cadenaOriginal = preg_replace('/\s+/', ' ', $cadenaOriginal);

		// Verificar que la cadena comience y termine correctamente
		if (!str_starts_with($cadenaOriginal, '||')) {
			$cadenaOriginal = '||' . $cadenaOriginal;
		}
		if (!str_ends_with($cadenaOriginal, '||')) {
			$cadenaOriginal .= '||';
		}

		return $cadenaOriginal;
	}
}