<?php
/**
 * Class for working with PO files
 *
 * @version $Id: po.php 33 2009-02-16 09:33:39Z nbachiyski $
 * @package pomo
 * @subpackage po
 */

require_once dirname(__FILE__) . '/translations.php';

define('PO_MAX_LINE_LEN', 79);

ini_set('auto_detect_line_endings', 1);

/**
 * Routines for working with PO files
 */
class PO extends Translations {


	/**
	 * Exports headers to a PO entry
	 *
	 * @return string msgid/msgstr PO entry for this PO file headers, doesn't contain newline at the end
	 */
	function export_headers() {
		$header_string = '';
		foreach($this->headers as $header => $value) {
			$header_string.= "$header: $value\n";
		}
		$poified = PO::poify($header_string);
		return rtrim("msgid \"\"\nmsgstr $poified");
	}

	/**
	 * Exports all entries to PO format
	 *
	 * @return string sequence of mgsgid/msgstr PO strings, doesn't containt newline at the end
	 */
	function export_entries() {
		//TODO sorting
		return implode("\n\n", array_map(array('PO', 'export_entry'), $this->entries));
	}

	/**
	 * Exports the whole PO file as a string
	 *
	 * @param bool $include_headers whether to include the headers in the export
	 * @return string ready for inclusion in PO file string for headers and all the enrtries
	 */
	function export($include_headers = true) {
		$res = '';
		if ($include_headers) {
			$res .= $this->export_headers();
			$res .= "\n\n";
		}
		$res .= $this->export_entries();
		return $res;
	}

	/**
	 * Same as {@link export}, but writes the result to a file
	 *
	 * @param string $filename where to write the PO string
	 * @param bool $include_headers whether to include tje headers in the export
	 * @return bool true on success, false on error
	 */
	function export_to_file($filename, $include_headers = true) {
		$fh = fopen($filename, 'w');
		if (false === $fh) return false;
		$export = $this->export($include_headers);
		$res = fwrite($fh, $export);
		if (false === $res) return false;
		return fclose($fh);
	}


	/**
	 * Formats a string in PO-style
	 *
	 * @static
	 * @param string $string the string to format
	 * @return string the poified string
	 */
	function poify($string) {
		$quote = '"';
		$slash = '\\';
		$newline = "\n";
		$tab = "\t";

		$replaces = array(
			"$slash" 	=> "$slash$slash",
			"$tab" 		=> '\t',
			"$quote"	=> "$slash$quote",
		);
		$string = str_replace(array_keys($replaces), array_values($replaces), $string);

		$po = array();
		foreach (explode($newline, $string) as $line) {
			$po[] = wordwrap($line, PO_MAX_LINE_LEN - 2, " $quote$newline$quote");
		}
		$po = $quote.implode("${slash}n$quote$newline$quote", $po).$quote;
		// add empty string on first line for readbility
		if (false !== strpos($po, $newline)) {
			$po = "$quote$quote$newline$po";
		}
		// remove empty strings
		$po = str_replace("$newline$quote$quote", '', $po);
		return $po;
	}

	/**
	 * Inserts $with in the beginning of every new line of $string and
	 * returns the modified string
	 *
	 * @static
	 * @param string $string prepend lines in this string
	 * @param string $with prepend lines with this string
	 */
	function prepend_each_line($string, $with) {
		$php_with = var_export($with, true);
		$lines = explode("\n", $string);
		// do not prepend the string on the last empty line, artefact by explode
		if ("\n" == substr($string, -1)) unset($lines[count($lines) - 1]);
		$res = implode("\n", array_map(create_function('$x', "return $php_with.\$x;"), $lines));
		// give back the empty line, we ignored above
		if ("\n" == substr($string, -1)) $res .= "\n";
		return $res;
	}

	/**
	 * Prepare a text as a comment -- wraps the lines and prepends #
	 * and a special character to each line
	 *
	 * @access private
	 * @param string $text the comment text
	 * @param string $char character to denote a special PO comment,
	 * 	like :, default is a space
	 */
	function comment_block($text, $char=' ') {
		$text = wordwrap($text, PO_MAX_LINE_LEN - 3);
		return PO::prepend_each_line($text, "#$char ");
	}

	/**
	 * Builds a string from the entry for inclusion in PO file
	 *
	 * @static
	 * @param object &$entry the entry to convert to po string
	 * @return string|bool PO-style formatted string for the entry or
	 * 	false if the entry is empty
	 */
	function export_entry(&$entry) {
		if (is_null($entry->singular)) return false;
		$po = array();
		if (!empty($entry->translator_comments)) $po[] = PO::comment_block($entry->translator_comments);
		if (!empty($entry->extracted_comments)) $po[] = PO::comment_block($entry->extracted_comments, '.');
		if (!empty($entry->references)) $po[] = PO::comment_block(implode(' ', $entry->references), ':');
		if (!empty($entry->flags)) $po[] = PO::comment_block(implode("\n", $entry->flags), ',');
		if (!is_null($entry->context)) $po[] = 'msgctxt '.PO::poify($entry->context);
		$po[] = 'msgid '.PO::poify($entry->singular);
		if (!$entry->is_plural) {
			$translation = empty($entry->translations)? '' : $entry->translations[0];
			$po[] = 'msgstr '.PO::poify($translation);
		} else {
			$po[] = 'msgid_plural '.PO::poify($entry->plural);
			$translations = empty($entry->translations)? array('', '') : $entry->translations;
			foreach($translations as $i => $translation) {
				$po[] = "msgstr[$i] ".PO::poify($translation);
			}
		}
		return implode("\n", $po);
	}

}
?>