<?php
/**
 * Implementation of conversion service class
 *
 * @category   DMS
 * @package    SeedDMS
 * @license    GPL 2
 * @version    @version@
 * @author     Uwe Steinmann <uwe@steinmann.cx>
 * @copyright  Copyright (C) 2021 Uwe Steinmann
 * @version    Release: @package_version@
 */

require_once("inc/inc.ClassConversionServiceBase.php");

define ('UTF32_BIG_ENDIAN_BOM'   , chr(0x00) . chr(0x00) . chr(0xFE) . chr(0xFF));
define ('UTF32_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE) . chr(0x00) . chr(0x00));
define ('UTF16_BIG_ENDIAN_BOM'   , chr(0xFE) . chr(0xFF));
define ('UTF16_LITTLE_ENDIAN_BOM', chr(0xFF) . chr(0xFE));
define ('UTF8_BOM'               , chr(0xEF) . chr(0xBB) . chr(0xBF));

/**
 * Implementation of conversion service class for text to text
 *
 * @category   DMS
 * @package    SeedDMS
 * @author     Uwe Steinmann <uwe@steinmann.cx>
 * @copyright  Copyright (C) 2021 Uwe Steinmann
 * @version    Release: @package_version@
 */
class SeedDMS_ConversionServiceTextToText extends SeedDMS_ConversionServiceBase {
	public function __construct($from, $to) {
		parent::__construct();
		$this->from = $from;
		$this->to = $to;
	}

	public function getInfo() {
		return "Pass through document contents";
	}

	protected function detect_utf_encoding($text) {
		$first2 = substr($text, 0, 2);
		$first3 = substr($text, 0, 3);
		$first4 = substr($text, 0, 3);

		if ($first3 == UTF8_BOM) return 'UTF-8';
		elseif ($first4 == UTF32_BIG_ENDIAN_BOM) return 'UTF-32BE';
		elseif ($first4 == UTF32_LITTLE_ENDIAN_BOM) return 'UTF-32LE';
		elseif ($first2 == UTF16_BIG_ENDIAN_BOM) return 'UTF-16BE';
		elseif ($first2 == UTF16_LITTLE_ENDIAN_BOM) return 'UTF-16LE';
		else return '';
	}

	public function convert($infile, $target = null, $params = array()) {
		$content = file_get_contents($infile);
		$encoding  = $this->detect_utf_encoding($content);
		// mb_detect_encoding() is not a good as detect_utf_encoding()
		// $encoding  = mb_detect_encoding($content);
		$content = mb_convert_encoding($content, 'utf8', $encoding);
		if($target) {
			file_put_contents($target, $content);
			return true;
		} else
			return $content;
	}
}