<?php

class QRbitstream
{
	public $data = array();

	public function size()
	{
		return count($this->data);
	}

	public function allocate($setLength)
	{
		$this->data = array_fill(0, $setLength, 0);
		return 0;
	}

	static public function newFromNum($bits, $num)
	{
		$bstream = new QRbitstream();
		$bstream->allocate($bits);
		$mask = 1 << $bits - 1;

		for ($i = 0; $i < $bits; $i++) {
			if ($num & $mask) {
				$bstream->data[$i] = 1;
			}
			else {
				$bstream->data[$i] = 0;
			}

			$mask = $mask >> 1;
		}

		return $bstream;
	}

	static public function newFromBytes($size, $data)
	{
		$bstream = new QRbitstream();
		$bstream->allocate($size * 8);
		$p = 0;

		for ($i = 0; $i < $size; $i++) {
			$mask = 128;

			for ($j = 0; $j < 8; $j++) {
				if ($data[$i] & $mask) {
					$bstream->data[$p] = 1;
				}
				else {
					$bstream->data[$p] = 0;
				}

				$p++;
				$mask = $mask >> 1;
			}
		}

		return $bstream;
	}

	public function append(QRbitstream $arg)
	{
		if (is_null($arg)) {
			return -1;
		}

		if ($arg->size() == 0) {
			return 0;
		}

		if ($this->size() == 0) {
			$this->data = $arg->data;
			return 0;
		}

		$this->data = array_values(array_merge($this->data, $arg->data));
		return 0;
	}

	public function appendNum($bits, $num)
	{
		if ($bits == 0) {
			return 0;
		}

		$b = QRbitstream::newFromNum($bits, $num);

		if (is_null($b)) {
			return -1;
		}

		$ret = $this->append($b);
		unset($b);
		return $ret;
	}

	public function appendBytes($size, $data)
	{
		if ($size == 0) {
			return 0;
		}

		$b = QRbitstream::newFromBytes($size, $data);

		if (is_null($b)) {
			return -1;
		}

		$ret = $this->append($b);
		unset($b);
		return $ret;
	}

	public function toByte()
	{
		$size = $this->size();

		if ($size == 0) {
			return array();
		}

		$data = array_fill(0, (int) (($size + 7) / 8), 0);
		$bytes = (int) ($size / 8);
		$p = 0;

		for ($i = 0; $i < $bytes; $i++) {
			$v = 0;

			for ($j = 0; $j < 8; $j++) {
				$v = $v << 1;
				$v |= $this->data[$p];
				$p++;
			}

			$data[$i] = $v;
		}

		if ($size & 7) {
			$v = 0;

			for ($j = 0; $j < ($size & 7); $j++) {
				$v = $v << 1;
				$v |= $this->data[$p];
				$p++;
			}

			$data[$bytes] = $v;
		}

		return $data;
	}
}


?>