<?php
/* $Id$ */
namespace Mammut\IO;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

use Mammut\Exception\IllegalStateException;

/**
 * Textfile io class
 *
 * Note: Could work with stream wrappers, but is unsupported!
 *
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\IO
 */
class Textfile extends File implements iLineReader {
	const _VERSION_ = '0.5.0.2';

	/**
	 * create a new file object
	 *
	 * @param string $path
	 *        	the path of the object
	 */
	public function __construct($path, $ro = false) {
		parent::__construct($path, $ro);
	}

	/**
	 * Skips the BOM on the beginning of a text file.
	 *
	 * Does nothing if current position is not 0
	 */
	protected function skipBOM() {
		if(ftell($this->fp) != 0)
			return;
		$test = fread($this->fp, 4);
		
		$target = 0;
		// UTF8 BOM
		if(substr($test, 0, 3) == "\xEF\xBB\xBF")
			$target = 3;
			// UTF16 BOM
		elseif(substr($test, 0, 2) == "\xFE\xFF")
			$target = 2;
		elseif(substr($test, 0, 2) == "\xFF\xFE")
			$target = 2;
		
		fseek($this->fp, $target);
	}

	/**
	 * (non-PHPdoc)
	 * @see \Mammut\IO\iLineReader::readLine()
	 */
	public function readLine($trim = TRUE) {
		if(!$this->isOpen())
			throw new IllegalStateException("file not opened");
		if($this->isEOF())
			return false;
		
		$this->skipBOM();
		$data = fgets($this->fp);
		if ($trim)
			$data = rtrim($data,"\r\n");
		
		return $data;
	}

	/**
	 * Writes a line in the file, followed by a newline character
	 * 
	 * @param string $data
	 *        	the string to write
	 * @throws IllegalStateException if the file is not open for writing
	 */
	public function writeLine($data) {
		if(!$this->isOpen())
			throw new IllegalStateException("file not opened");
		fwrite($this->fp, $data . PHP_EOL);
	}
}