<?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/src/CFDI40Generator.php
 * \ingroup    cfdixml
 * \brief      Clase principal para la generación de CFDI versión 4.0
 */
require_once __DIR__ . '/Certificado.php';
require_once __DIR__ . '/CadenaOriginalBuilder.php';

class CFDI40Generator
{
	private $xml;
	private $root;
	private $certificado;
	private $emisor;
	private $receptor;
	private $conceptos = [];
	private $impuestos = [];
	private $complementos = [];
	private $cadenaOriginalBuilder; // Nueva propiedad

	public function __construct()
	{
		$this->xml = new \DOMDocument('1.0', 'UTF-8');
		$this->xml->formatOutput = true;
		$this->certificado = new Certificado();

		// Si no se proporciona xsltPath, usar la URL del SAT por defecto
		$xsltPath = $xsltPath ?? 'http://www.sat.gob.mx/sitio_internet/cfd/4/cadenaoriginal_4_0/cadenaoriginal_4_0.xslt';
		$this->cadenaOriginalBuilder = new CadenaOriginalBuilder($xsltPath);
	}

	/**
	 * Creates the root node of the CFDI (Comprobante Fiscal Digital por Internet).
	 *
	 * @param array $datos An associative array containing the necessary data for the CFDI.
	 * @return CFDIGenerator Returns the instance of the CFDIGenerator class for method chaining.
	 *
	 * @throws Exception If any required attribute is missing in the $datos array.
	 */
	public function createComprobante($datos)
	{
		// Crear el nodo raíz del CFDI
		$this->root = $this->xml->createElement('cfdi:Comprobante');
		$this->xml->appendChild($this->root);

		// Agregar namespaces
		$this->root->setAttribute('xmlns:cfdi', 'http://www.sat.gob.mx/cfd/4');
		$this->root->setAttribute('xmlns:xsi', 'http://www.w3.org/2001/XMLSchema-instance');
		$this->root->setAttribute('xsi:schemaLocation', 'http://www.sat.gob.mx/cfd/4 http://www.sat.gob.mx/sitio_internet/cfd/4/cfdv40.xsd');

		// Atributos obligatorios del CFDI 4.0
		$this->root->setAttribute('Version', '4.0');
		$this->root->setAttribute('Fecha', date('Y-m-d\TH:i:s'));
		$this->root->setAttribute('Moneda', $datos['Moneda'] ?? 'MXN');
		$this->root->setAttribute('TipoDeComprobante', $datos['TipoDeComprobante']);
		$this->root->setAttribute('Exportacion', $datos['Exportacion'] ?? '01');
		$this->root->setAttribute('LugarExpedicion', $datos['LugarExpedicion']);

		// Atributos opcionales
		if (isset($datos['Serie'])) $this->root->setAttribute('Serie', $datos['Serie']);
		if (isset($datos['Folio'])) $this->root->setAttribute('Folio', $datos['Folio']);
		if (isset($datos['FormaPago'])) $this->root->setAttribute('FormaPago', $datos['FormaPago']);
		if (isset($datos['MetodoPago'])) $this->root->setAttribute('MetodoPago', $datos['MetodoPago']);

		return $this;
	}

	/**
	 * Adds the Emisor (Issuer) node to the CFDI XML structure.
	 *
	 * This function creates and appends the 'cfdi:Emisor' element to the root of the XML document,
	 * setting the required attributes for the issuer of the CFDI.
	 *
	 * @param array $datos An associative array containing the issuer's information with the following keys:
	 *                     - 'Rfc': The RFC (Registro Federal de Contribuyentes) of the issuer.
	 *                     - 'Nombre': The legal name of the issuer.
	 *                     - 'RegimenFiscal': The tax regime code under which the issuer operates.
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function agregarEmisor($datos)
	{
		$emisor = $this->xml->createElement('cfdi:Emisor');
		$this->root->appendChild($emisor);

		$emisor->setAttribute('Rfc', $datos['Rfc']);
		$emisor->setAttribute('Nombre', $datos['Nombre']);
		$emisor->setAttribute('RegimenFiscal', $datos['RegimenFiscal']);

		$this->emisor = $datos;
		return $this;
	}

	/**
	 * Adds the Receptor (Receiver) node to the CFDI XML structure.
	 *
	 * This function creates and appends the 'cfdi:Receptor' element to the root of the XML document,
	 * setting the required attributes for the receiver of the CFDI.
	 *
	 * @param array $datos An associative array containing the receiver's information with the following keys:
	 *                     - 'Rfc': The RFC (Registro Federal de Contribuyentes) of the receiver.
	 *                     - 'Nombre': The legal name of the receiver.
	 *                     - 'DomicilioFiscalReceptor': The tax address of the receiver.
	 *                     - 'RegimenFiscalReceptor': The tax regime code under which the receiver operates.
	 *                     - 'UsoCFDI': The intended use of the CFDI.
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function agregarReceptor($datos)
	{
		$receptor = $this->xml->createElement('cfdi:Receptor');
		$this->root->appendChild($receptor);

		$receptor->setAttribute('Rfc', $datos['Rfc']);
		$receptor->setAttribute('Nombre', $datos['Nombre']);
		$receptor->setAttribute('DomicilioFiscalReceptor', $datos['DomicilioFiscalReceptor']);
		$receptor->setAttribute('RegimenFiscalReceptor', $datos['RegimenFiscalReceptor']);
		$receptor->setAttribute('UsoCFDI', $datos['UsoCFDI']);

		$this->receptor = $datos;
		return $this;
	}
	/**
	 * Adds a concept (item or service) to the CFDI.
	 *
	 * This method appends a new concept to the internal array of concepts.
	 * Each concept represents an item or service being invoiced in the CFDI.
	 *
	 * @param array $concepto An associative array containing the details of the concept.
	 *                        Expected keys include:
	 *                        - ClaveProdServ: Product or service key
	 *                        - Cantidad: Quantity
	 *                        - ClaveUnidad: Unit key
	 *                        - Descripcion: Description
	 *                        - ValorUnitario: Unit value
	 *                        - Importe: Total amount
	 *                        - ObjetoImp: Tax object
	 *                        - NoIdentificacion: (Optional) Identification number
	 *                        - Impuestos: (Optional) Taxes associated with the concept
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function agregarConcepto($concepto)
	{
		$this->conceptos[] = $concepto;
		return $this;
	}

	/**
	 * Adds all concepts to the CFDI XML structure.
	 *
	 * This method creates the 'cfdi:Conceptos' node in the XML document and populates it
	 * with all the concepts that have been added to the CFDI. For each concept, it sets
	 * the required attributes and optionally adds identification and tax information.
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function agregarConceptos()
	{
		$conceptosNode = $this->xml->createElement('cfdi:Conceptos');
		$this->root->appendChild($conceptosNode);

		foreach ($this->conceptos as $datos) {
			$concepto = $this->xml->createElement('cfdi:Concepto');
			$conceptosNode->appendChild($concepto);

			// Atributos obligatorios
			$concepto->setAttribute('ClaveProdServ', $datos['ClaveProdServ']);
			$concepto->setAttribute('Cantidad', $datos['Cantidad']);
			$concepto->setAttribute('ClaveUnidad', $datos['ClaveUnidad']);
			$concepto->setAttribute('Descripcion', $datos['Descripcion']);
			$concepto->setAttribute('ValorUnitario', $datos['ValorUnitario']);
			$concepto->setAttribute('Importe', $datos['Importe']);
			$concepto->setAttribute('ObjetoImp', $datos['ObjetoImp']);

			// Atributos opcionales
			if (isset($datos['NoIdentificacion'])) {
				$concepto->setAttribute('NoIdentificacion', $datos['NoIdentificacion']);
			}

			// Agregar impuestos del concepto si existen
			if (isset($datos['Impuestos'])) {
				$this->agregarImpuestosConcepto($concepto, $datos['Impuestos']);
			}
		}

		return $this;
	}

	/**
	 * Adds tax information to a concept node in the CFDI XML structure.
	 *
	 * This method creates and appends tax-related nodes (Traslados and Retenciones)
	 * to the given concept node. It handles both transferred taxes (like IVA and IEPS)
	 * and withheld taxes.
	 *
	 * @param DOMElement $concepto The concept node to which tax information will be added.
	 * @param array $impuestos An associative array containing tax information:
	 *                         - 'Traslados': Array of transferred taxes (IVA, IEPS)
	 *                         - 'Retenciones': Array of withheld taxes
	 *
	 * @return void This method doesn't return a value, it modifies the XML structure directly.
	 */
	private function agregarImpuestosConcepto($concepto, $impuestos)
	{
		$impuestosNode = $this->xml->createElement('cfdi:Impuestos');
		$concepto->appendChild($impuestosNode);

		// Agregar traslados
		if (isset($impuestos['Traslados'])) {
			$impuestosNode = $this->xml->createElement('cfdi:Impuestos');
			$concepto->appendChild($impuestosNode);

			// Agregar traslados (IEPS e IVA)
			if (isset($impuestos['Traslados'])) {
				$trasladosNode = $this->xml->createElement('cfdi:Traslados');
				$impuestosNode->appendChild($trasladosNode);

				// Ordenamos los traslados: primero IEPS (003), luego IVA (002)
				usort($impuestos['Traslados'], function ($a, $b) {
					return strcmp($b['Impuesto'], $a['Impuesto']);
				});

				foreach ($impuestos['Traslados'] as $traslado) {
					$trasladoNode = $this->xml->createElement('cfdi:Traslado');
					$trasladosNode->appendChild($trasladoNode);

					$trasladoNode->setAttribute('Base', $traslado['Base']);
					$trasladoNode->setAttribute('Impuesto', $traslado['Impuesto']);
					$trasladoNode->setAttribute('TipoFactor', $traslado['TipoFactor']);

					if ($traslado['TipoFactor'] !== 'Exento') {
						$trasladoNode->setAttribute('TasaOCuota', $traslado['TasaOCuota']);
						$trasladoNode->setAttribute('Importe', $traslado['Importe']);
					}
				}
			}
		}
		// Agregar retenciones
		if (isset($impuestos['Retenciones'])) {
			$retencionesNode = $this->xml->createElement('cfdi:Retenciones');
			$impuestosNode->appendChild($retencionesNode);

			foreach ($impuestos['Retenciones'] as $retencion) {
				$retencionNode = $this->xml->createElement('cfdi:Retencion');
				$retencionesNode->appendChild($retencionNode);

				$retencionNode->setAttribute('Base', $retencion['Base']);
				$retencionNode->setAttribute('Impuesto', $retencion['Impuesto']);
				$retencionNode->setAttribute('TipoFactor', $retencion['TipoFactor']);
				$retencionNode->setAttribute('TasaOCuota', $retencion['TasaOCuota']);
				$retencionNode->setAttribute('Importe', $retencion['Importe']);
			}
		}
	}
	/**
	 * Calculates taxes (IEPS and IVA) for a given product or service.
	 *
	 * This function computes the taxes based on the unit price, quantity, and tax rates.
	 * It first calculates IEPS (if applicable) and then IVA on the total amount including IEPS.
	 *
	 * @param float $precioUnitario The unit price of the product or service.
	 * @param float $cantidad The quantity of the product or service.
	 * @param float $tasaIEPS The IEPS (Special Tax on Production and Services) rate. Defaults to 0.
	 * @param float $tasaIVA The IVA (Value Added Tax) rate. Defaults to 0.16 (16%).
	 *
	 * @return array Returns an associative array containing the calculated taxes under the 'Traslados' key.
	 *               Each tax (IEPS and/or IVA) is represented as an array with 'Base', 'Impuesto',
	 *               'TipoFactor', 'TasaOCuota', and 'Importe' keys.
	 */
	public function calcularImpuestos($precioUnitario, $cantidad, $tasaIEPS = 0, $tasaIVA = 0.16)
	{
		$importe = $precioUnitario * $cantidad;
		$impuestos = ['Traslados' => []];

		// Si hay IEPS, calcularlo primero
		if ($tasaIEPS > 0) {
			$importeIEPS = $importe * $tasaIEPS;
			$impuestos['Traslados'][] = [
				'Base' => number_format($importe, 2, '.', ''),
				'Impuesto' => '003', // Clave para IEPS
				'TipoFactor' => 'Tasa',
				'TasaOCuota' => number_format($tasaIEPS, 6, '.', ''),
				'Importe' => number_format($importeIEPS, 2, '.', '')
			];

			// La base para el IVA incluye el IEPS
			$importe += $importeIEPS;
		}

		// Calcular IVA sobre el importe + IEPS
		if ($tasaIVA > 0) {
			$importeIVA = $importe * $tasaIVA;
			$impuestos['Traslados'][] = [
				'Base' => number_format($importe, 2, '.', ''),
				'Impuesto' => '002', // Clave para IVA
				'TipoFactor' => 'Tasa',
				'TasaOCuota' => number_format($tasaIVA, 6, '.', ''),
				'Importe' => number_format($importeIVA, 2, '.', '')
			];
		}

		return $impuestos;
	}

	/**
	 * Adds a concept (item or service) to the CFDI with calculated taxes.
	 *
	 * This method calculates the taxes for a given concept based on its unit value and quantity,
	 * then adds the concept with its calculated taxes to the CFDI.
	 *
	 * @param array $datos An associative array containing the concept details (e.g., 'ValorUnitario', 'Cantidad').
	 * @param float $tasaIEPS The IEPS (Special Tax on Production and Services) rate. Defaults to 0.
	 * @param float $tasaIVA The IVA (Value Added Tax) rate. Defaults to 0.16 (16%).
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function agregarConceptoConImpuestos($datos, $tasaIEPS = 0, $tasaIVA = 0.16, $retenciones = []) {
		// Calcular importe base
		$importe = $datos['ValorUnitario'] * $datos['Cantidad'];

		// Calcular impuestos
		$impuestos = $this->calcularImpuestos(
			floatval($datos['ValorUnitario']),
			floatval($datos['Cantidad']),
			$tasaIEPS,
			$tasaIVA
		);

		// Agregar retenciones si existen
		if (!empty($retenciones)) {
			$impuestos['Retenciones'] = array_map(function($retencion) use ($importe) {
				return [
					'Base' => $importe,
					'Impuesto' => $retencion['Impuesto'],  // '001' para ISR, '002' para IVA
					'TipoFactor' => 'Tasa',
					'TasaOCuota' => number_format($retencion['TasaOCuota'], 6, '.', ''),
					'Importe' => number_format($importe * $retencion['TasaOCuota'], 2, '.', '')
				];
			}, $retenciones);
		}

		$datos['Impuestos'] = $impuestos;
		$this->agregarConcepto($datos);
		return $this;
	}
	/**
	 * Calculates and sets the total amounts for the CFDI.
	 *
	 * This method iterates through all the concepts (items or services) in the CFDI,
	 * calculating the subtotal, total transferred taxes, total withheld taxes, and the overall total.
	 * It then sets these calculated values as attributes on the root element of the CFDI.
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 */
	public function calcularTotales()
	{
		$subtotal = 0;
		$total = 0;
		$totalImpuestosTrasladados = 0;
		$totalImpuestosRetenidos = 0;

		foreach ($this->conceptos as $concepto) {
			$subtotal += floatval($concepto['Importe']);

			if (isset($concepto['Impuestos'])) {
				if (isset($concepto['Impuestos']['Traslados'])) {
					foreach ($concepto['Impuestos']['Traslados'] as $traslado) {
						if ($traslado['TipoFactor'] !== 'Exento') {
							$totalImpuestosTrasladados += floatval($traslado['Importe']);
						}
					}
				}
				if (isset($concepto['Impuestos']['Retenciones'])) {
					foreach ($concepto['Impuestos']['Retenciones'] as $retencion) {
						$totalImpuestosRetenidos += floatval($retencion['Importe']);
					}
				}
			}
		}

		$total = $subtotal + $totalImpuestosTrasladados - $totalImpuestosRetenidos;

		$this->root->setAttribute('SubTotal', number_format($subtotal, 2, '.', ''));
		$this->root->setAttribute('Total', number_format($total, 2, '.', ''));

		return $this;
	}

	/**
	 * Seals the CFDI (Comprobante Fiscal Digital por Internet) by generating and adding the required certificate information and digital signature.
	 *
	 * This method performs the following steps:
	 * 1. Generates the original string (cadena original) for the CFDI.
	 * 2. Processes the certificate to obtain its data.
	 * 3. Generates the digital signature (sello) using the private key.
	 * 4. Adds the certificate number, certificate, and digital signature to the CFDI as attributes.
	 *
	 * @param string $certificadoPath The file path to the digital certificate (.cer file).
	 * @param string $llavePrivadaPath The file path to the private key (.key file).
	 * @param string $password The password to decrypt the private key.
	 *
	 * @return CFDI40Generator Returns the current instance of the class for method chaining.
	 *
	 * @throws \Exception If there's an error processing the certificate or generating the digital signature.
	 */
	public function sellarCFDI($certificadoPath, $llavePrivadaPath, $password)
	{
		// Generar cadena original
		$cadenaOriginal = $this->generarCadenaOriginal();

		// Obtener datos del certificado
		$certificadoData = $this->certificado->procesarCertificado($certificadoPath);

		// Generar sello
		$sello = $this->certificado->generarSello($cadenaOriginal, $llavePrivadaPath, $password);

		// Agregar atributos al comprobante
		$this->root->setAttribute('NoCertificado', $certificadoData['noCertificado']);
		$this->root->setAttribute('Certificado', $certificadoData['certificado']);
		$this->root->setAttribute('Sello', $sello);

		return $this;
	}


	/**
	 * Genera la cadena original del CFDI usando el XSLT oficial del SAT
	 *
	 * @return string La cadena original del CFDI
	 * @throws Exception Si hay error al generar la cadena original
	 */
	private function generarCadenaOriginal()
	{
		try {
			// Verificar que el XML esté completo
			if (!$this->root || !$this->xml) {
				throw new \Exception("El CFDI no está completamente generado");
			}

			// Obtener el XML actual
			$xmlString = $this->xml->saveXML();

			// Generar y retornar la cadena original
			$cadenaOriginal = $this->cadenaOriginalBuilder->buildCadenaOriginal($xmlString);

			// Verificar que la cadena original se generó correctamente
			if (empty($cadenaOriginal)) {
				throw new \Exception("Error al generar la cadena original: resultado vacío");
			}

			return $cadenaOriginal;
		} catch (\Exception $e) {
			throw new \Exception("Error al generar la cadena original: " . $e->getMessage());
		}
	}

	/**
	 * Retrieves the XML representation of the CFDI.
	 *
	 * This method returns the complete XML document of the CFDI (Comprobante Fiscal Digital por Internet)
	 * that has been generated and processed by this class.
	 *
	 * @return string The XML string representation of the CFDI.
	 */
	public function getXML()
	{
		return $this->xml->saveXML();
	}
}