#!/usr/bin/php
<?php

function Usage()
{
	echo basename(__FILE__)." --from from_encoding --to to_encoding input_file output_file\n";
}

function forceTranscoding($fromEncoding, $toEncoding, $str) {
	$result = "";

	for ($i = 0; $i < strlen($str); $i++) {
		$sbit = ord(substr($str, $i, 1));
		if ($sbit <= 127) {
			$result .= substr($str, $i, 1);
		} else {
			$new_word = iconv($fromEncoding, $toEncoding, substr($str, $i, 2));
			$result.= ($new_word=="") ? " " : $new_word;
			$i++;
		}
	}

	return $result;
}

function main($fromEncoding, $toEncoding, $inputPath, $outputPath)
{
	$fileContent = file_get_contents($inputPath);

	if ('UTF-8_withBOM' == $toEncoding) {
		$toEncoding = 'UTF-8';
		$fileContent = chr(239) . chr(187) . chr(191) . $fileContent;
	}

	if ('UTF-8_withBOM' == $fromEncoding) {
		$fromEncoding = 'UTF-8';
	}
	$result = iconv($fromEncoding, "{$toEncoding}//IGNORE", $fileContent);

	if ("" == $result && 0 < strlen($fileContent)) {
		$result = forceTranscoding($fromEncoding, $toEncoding, $fileContent);
	}

	file_put_contents($outputPath, $result);
}

$opts = '';
$longOpts = array('to:', 'from:');
$inputOptions = getopt($opts, $longOpts);

if (empty($inputOptions['to']) || empty($inputOptions['from'])) {
	Usage();
	exit(1);
}

$leftArray = array_slice($argv, 5);
if (count($leftArray) !== 2) {
	Usage();
	exit(1);
}

ini_set('display_errors', 'On');
main($inputOptions['from'], $inputOptions['to'], $leftArray[0], $leftArray[1]);

?>