<?php

class ArrayFileStream
{
    private $open_file;
    private $position;

    private static $fs;

    static function set_filesystem(array $fs) {
        ArrayFileStream::$fs = $fs;
    }

    private static function &get_element($path) {
        $result =& ArrayFileStream::$fs;
        foreach (preg_split('/\//', $path, -1, PREG_SPLIT_NO_EMPTY) as $element) {
            if (!isset($result[$element])) {
                $null = NULL;
                return $null;
            }
            $result =& $result[$element];
        }
        return $result;
    }

    private static function &get_file($path) {
        $url = parse_url($path);
        $file =& self::get_element($url['host'] . $url['path']);

        if (is_null($file)) {
            throw new Exception("file not found.");
        }
        return $file;
    }

    public function stream_close() {
        # nothing to do
    }

    public function stream_flush() {
        # nothing to do
    }

    public function stream_open($path, $mode, $options, $opened_path) {
        try {
            $this->open_file =& self::get_file($path);
            $this->position = 0;
            return true;
        } catch (Exception $e) {
            return false;
        }
    }

    public function stream_read($count) {
        $ret = mb_substr($this->open_file, $this->position, $count);
        $this->position += mb_strlen($ret);
        return $ret;
    }

    public function stream_write($data) {
        $left  = mb_substr($this->open_file, 0, $this->position);
        $right = mb_substr($this->open_file, $this->position + mb_strlen($data));
        $this->open_file = $left . $data . $right;
        $this->position += mb_strlen($data);
        return mb_strlen($data);
    }

    public function stream_tell() {
        return $this->position;
    }

    public function stream_eof() {
        return $this->position >= mb_strlen($this->open_file);
    }

    public function stream_seek($offset, $whence) {

        switch ($whence) {
            case SEEK_SET:
                if ($offset < mb_strlen($this->open_file) && $offset >= 0) {
                    $this->position = $offset;
                    return true;
                }
                else {
                    return false;
                }
                break;

            case SEEK_CUR:
                if ($offset >= 0) {
                    $this->position += $offset;
                    return true;
                }
                else {
                    return false;
                }
                break;

            case SEEK_END:
                if (mb_strlen($this->open_file) + $offset >= 0) {
                    $this->position = mb_strlen($this->open_file) + $offset;
                    return true;
                }
                else {
                    return false;
                }
                break;

            default:
                return false;
        }
    }

    public function stream_set_option(int $option, int $arg1, int $arg2)
    {
    }

    public function stream_stat() {
        return array('size' => is_array($this->open_file)
                     ? sizeof($this->open_file)
                     : mb_strlen($this->open_file));
    }

    public function unlink($path) {

        $parent =& self::get_file(dirname($path));

        if (is_array($parent) && isset($parent[basename($path)])) {
            unset($parent[basename($path)]);
            return TRUE;
        }

        return FALSE;
    }

    public function rename($path_from, $path_to) {
        throw new Exception('not implemented yet');
    }

    public function mkdir($path, $mode, $options) {
        throw new Exception('not implemented yet');
    }

    public function rmdir($path, $options) {
        throw new Exception('not implemented yet');
    }

    public function dir_opendir($path, $options) {
        throw new Exception('not implemented yet');
    }

    public function url_stat($path, $flags) {
        $time = time();

        $keys = array(
            'dev'     => 0,
            'ino'     => 0,
            'mode'    => 33216, // chmod 700
            'nlink'   => 0,
            'uid'     => function_exists('posix_getuid') ? posix_getuid() : 0,
            'gid'     => function_exists('posix_getgid') ? posix_getgid() : 0,
            'rdev'    => 0,
            'size'    => $flags & STREAM_URL_STAT_QUIET
            ? @mb_strlen($this->_pointer) : mb_strlen($this->_pointer),
            'atime'   => $time,
            'mtime'   => $time,
            'ctime'   => $time,
            'blksize' => 0,
            'blocks'  => 0
        );
        return array_merge(array_values($keys), $keys);
    }

    public function dir_readdir() {
        throw new Exception('not implemented yet');
    }

    public function dir_rewinddir() {
        throw new Exception('not implemented yet');
    }

    public function dir_closedir() {
        throw new Exception('not implemented yet');
    }
}


#ArrayFileStream::set_filesystem(
#  array('tmp' =>
#    array('a' => 'my content',
#          'b' => '<? echo "hallo welt!";')));


#stream_wrapper_register("var", "ArrayFileStream")
#    or die("Failed to register protocol");

#$fp = fopen("var://tmp/a", "rw+");


#while (!feof($fp)) {
#    var_dump(fgets($fp));
#}

#fwrite($fp, "line1\n");
#fwrite($fp, "line2\n");
#fwrite($fp, "line3\n");

#rewind($fp);

#var_dump(file_get_contents('var://tmp/a'));

#fclose($fp);
#unlink('var://tmp/a');

#var_dump(include 'var://tmp/b');