<?php
/**
 * Class for working with PO files
 *
 * @version $Id: po.php 718 2012-10-31 00:32:02Z 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
 */
if ( !class_exists( 'PO' ) ):
class PO extends Gettext_Translations {

	var $comments_before_headers = '';

	/**
	 * Exports headers to a PO entry
	 *
	 * @return string msgid/msgstr PO entry for this PO file headers, doesn't contain newline at the end
	 */
	public function export_headers() {
		$header_string = '';
		foreach( $this->headers as $header => $value ) {
			$header_string.= "$header: $value\n";
		}
		$poified = PO::poify( $header_string );
		if ( $this->comments_before_headers )
			$before_headers = $this->prepend_each_line( rtrim( $this->comments_before_headers ) . "\n", '# ');
		else
			$before_headers = '';
		return rtrim( "{$before_headers}msgid \"\"\nmsgstr $poified" );
	}

	/**
	 * Exports all entries to PO format
	 *
	 * @return string sequence of mgsgid/msgstr PO strings, doesn't containt newline at the end
	 */
	public 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
	 */
	public 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 );
	}

	/**
	 * Text to include as a comment before the start of the PO contents
	 *
	 * Doesn't need to include # in the beginning of lines, these are added automatically
	 */
	public function set_comment_before_headers( $text ) {
		$this->comments_before_headers = $text;
	}

	/**
	 * Formats a string in PO-style
	 *
	 * @static
	 * @param string $string the string to format
	 * @return string the poified string
	 */
	public static function poify( $string ) {
		$quote = '"';
		$slash = '\\';
		$newline = "\n";

		$replaces = array(
			"$slash" => "$slash$slash",
			"$quote" => "$slash$quote",
			"\t"     => '\t',
		);

		$string = str_replace( array_keys( $replaces ), array_values( $replaces ), $string );

		$po = $quote.implode( "${slash}n$quote$newline$quote", explode( $newline, $string ) ) . $quote;
		// add empty string on first line for readbility
		if ( false !== strpos( $string, $newline ) && ( substr_count( $string, $newline ) > 1 || !( $newline === substr( $string, -strlen( $newline ) ) ) ) ) {
			$po = "$quote$quote$newline$po";
		}
		// remove empty strings
		$po = str_replace( "$newline$quote$quote", '', $po );
		return $po;
	}

	/**
	 * Gives back the original string from a PO-formatted string
	 *
	 * @static
	 * @param string $string PO-formatted string
	 * @return string enascaped string
	 */
	public static function unpoify( $string ) {
		$escapes = array( 't' => "\t",
						 'n'  => "\n",
						 '\\' => '\\'
						);
		$lines = array_map( 'trim', explode( "\n", $string ) );
		$lines = array_map( array( 'PO', 'trim_quotes' ), $lines );
		$unpoified = '';
		$previous_is_backslash = false;
		foreach( $lines as $line ) {
			preg_match_all( '/./u', $line, $chars );
			$chars = $chars[0];
			foreach( $chars as $char ) {
				if ( !$previous_is_backslash ) {
					if ( '\\' == $char )
						$previous_is_backslash = true;
					else
						$unpoified .= $char;
				} else {
					$previous_is_backslash = false;
					$unpoified .= isset( $escapes[ $char ] )? $escapes[ $char ] : $char;
				}
			}
		}
		return $unpoified;
	}

	/**
	 * 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
	 */
	public static function prepend_each_line( $string, $with ) {
		$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] );
		$res = implode( "\n", array_map( function ($x) use ($with) { return $with.$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
	 */
	public static 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 $entry the entry to convert to po string
	 * @return string|bool PO-style formatted string for the entry or
	 * 	false if the entry is empty
	 */
	public static function export_entry($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( ", ", $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 );
	}

	public function import_from_file( $filename ) {
		$f = fopen( $filename, 'r' );
		if ( !$f ) return false;
		$lineno = 0;
		while ( true ) {
			$res = $this->read_entry($f, $lineno);
			if ( !$res ) break;
			if ( $res['entry']->singular == '' ) {
				$this->set_headers( $this->make_headers( $res['entry']->translations[0] ) );
			} else {
				$this->add_entry( $res['entry'] );
			}
		}
		PO::read_line( $f, 'clear' );
		if ( false === $res ) {
			return false;
		}
		if ( ! $this->headers && ! $this->entries ) {
			return false;
		}
		return true;
	}

	public function read_entry( $f, $lineno = 0 ) {
		$entry = new Translation_Entry();
		// where were we in the last step
		// can be: comment, msgctxt, msgid, msgid_plural, msgstr, msgstr_plural
		$context = '';
		$msgstr_index = 0;
		$is_final = function ($context) { return $context == "msgstr" || $context == "msgstr_plural"; };
		while ( true ) {
			$lineno++;
			$line = PO::read_line( $f );
			if ( !$line )  {
				if ( feof( $f ) ) {
					if ( $is_final( $context ) )
						break;
					elseif ( !$context ) // we haven't read a line and eof came
						return null;
					else
						return false;
				} else {
					return false;
				}
			}
			if ( $line == "\n" ) continue;
			$line = trim($line);
			if ( preg_match( '/^#/', $line, $m ) ) {
				// the comment is the start of a new entry
				if ( $is_final( $context ) ) {
					PO::read_line($f, 'put-back');
					$lineno--;
					break;
				}
				// comments have to be at the beginning
				if ( $context && $context != 'comment' ) {
					return false;
				}
				// add comment
				$this->add_comment_to_entry( $entry, $line );
			} elseif ( preg_match( '/^msgctxt\s+(".*")/', $line, $m ) ) {
				if ( $is_final( $context ) ) {
					PO::read_line( $f, 'put-back' );
					$lineno--;
					break;
				}
				if ( $context && $context != 'comment' ) {
					return false;
				}
				$context = 'msgctxt';
				$entry->context .= PO::unpoify( $m[1] );
			} elseif (preg_match( '/^msgid\s+(".*")/', $line, $m ) ) {
				if ( $is_final( $context ) ) {
					PO::read_line( $f, 'put-back' );
					$lineno--;
					break;
				}
				if ( $context && $context != 'msgctxt' && $context != 'comment' ) {
					return false;
				}
				$context = 'msgid';
				$entry->singular .= PO::unpoify( $m[1] );
			} elseif ( preg_match( '/^msgid_plural\s+(".*")/', $line, $m ) ) {
				if ( $context != 'msgid' ) {
					return false;
				}
				$context = 'msgid_plural';
				$entry->is_plural = true;
				$entry->plural .= PO::unpoify($m[1]);
			} elseif ( preg_match( '/^msgstr\s+(".*")/', $line, $m ) ) {
				if ( $context != 'msgid' ) {
					return false;
				}
				$context = 'msgstr';
				$entry->translations = array(PO::unpoify($m[1]));
			} elseif ( preg_match( '/^msgstr\[(\d+)\]\s+(".*")/', $line, $m ) ) {
				if ( $context != 'msgid_plural' && $context != 'msgstr_plural' ) {
					return false;
				}
				$context = 'msgstr_plural';
				$msgstr_index = $m[1];
				$entry->translations[$m[1]] = PO::unpoify( $m[2] );
			} elseif ( preg_match( '/^".*"$/', $line ) ) {
				$unpoified = PO::unpoify($line);
				switch ( $context ) {
					case 'msgid':
						$entry->singular .= $unpoified; break;
					case 'msgctxt':
						$entry->context .= $unpoified; break;
					case 'msgid_plural':
						$entry->plural .= $unpoified; break;
					case 'msgstr':
						$entry->translations[0] .= $unpoified; break;
					case 'msgstr_plural':
						$entry->translations[ $msgstr_index ] .= $unpoified; break;
					default:
						return false;
				}
			} else {
				return false;
			}
		}
		if ( array() == array_filter( $entry->translations, function ($t) { return $t || "0" === $t; } ) ) {
			$entry->translations = array();
		}
		return array( 'entry' => $entry, 'lineno' => $lineno );
	}

	public static function read_line( $f, $action = 'read' ) {
		static $last_line = '';
		static $use_last_line = false;
		if ( 'clear' == $action ) {
			$last_line = '';
			return true;
		}
		if ( 'put-back' == $action ) {
			$use_last_line = true;
			return true;
		}
		$line = $use_last_line? $last_line : fgets( $f );
		$line = ( "\r\n" == substr( $line, -2 ) ) ? rtrim( $line, "\r\n" ) . "\n" : $line;
		$last_line = $line;
		$use_last_line = false;
		return $line;
	}

	public static function add_comment_to_entry( &$entry, $po_comment_line ) {
		$first_two = substr( $po_comment_line, 0, 2 );
		$comment = trim( substr( $po_comment_line, 2 ) );
		if ( '#:' == $first_two ) {
			$entry->references = array_merge( $entry->references, preg_split( '/\s+/', $comment ) );
		} elseif ( '#.' == $first_two ) {
			$entry->extracted_comments = trim( $entry->extracted_comments . "\n" . $comment );
		} elseif ( '#,' == $first_two ) {
			$entry->flags = array_merge( $entry->flags, preg_split( '/,\s*/', $comment ) );
		} else {
			$entry->translator_comments = trim( $entry->translator_comments . "\n" . $comment );
		}
	}

	public static function trim_quotes( $s ) {
		if ( substr( $s, 0, 1 ) == '"' ) $s = substr( $s, 1 );
		if ( substr( $s, -1, 1 ) == '"' ) $s = substr( $s, 0, -1 );
		return $s;
	}
}
endif;