<?php

class QRmask
{
	public $runLength = array();

	public function __construct()
	{
		$this->runLength = array_fill(0, QRSPEC_WIDTH_MAX + 1, 0);
	}

	public function writeFormatInformation($width, &$frame, $mask, $level)
	{
		$blacks = 0;
		$format = QRspec::getFormatInfo($mask, $level);

		for ($i = 0; $i < 8; $i++) {
			if ($format & 1) {
				$blacks += 2;
				$v = 133;
			}
			else {
				$v = 132;
			}

			$frame[8][$width - 1 - $i] = chr($v);

			if ($i < 6) {
				$frame[$i][8] = chr($v);
			}
			else {
				$frame[$i + 1][8] = chr($v);
			}

			$format = $format >> 1;
		}

		for ($i = 0; $i < 7; $i++) {
			if ($format & 1) {
				$blacks += 2;
				$v = 133;
			}
			else {
				$v = 132;
			}

			$frame[$width - 7 + $i][8] = chr($v);

			if ($i == 0) {
				$frame[8][7] = chr($v);
			}
			else {
				$frame[8][6 - $i] = chr($v);
			}

			$format = $format >> 1;
		}

		return $blacks;
	}

	public function mask0($x, $y)
	{
		return $x + $y & 1;
	}

	public function mask1($x, $y)
	{
		return $y & 1;
	}

	public function mask2($x, $y)
	{
		return $x % 3;
	}

	public function mask3($x, $y)
	{
		return ($x + $y) % 3;
	}

	public function mask4($x, $y)
	{
		return (int) ($y / 2) + (int) ($x / 3) & 1;
	}

	public function mask5($x, $y)
	{
		return ($x * $y & 1) + $x * $y % 3;
	}

	public function mask6($x, $y)
	{
		return ($x * $y & 1) + $x * $y % 3 & 1;
	}

	public function mask7($x, $y)
	{
		return $x * $y % 3 + ($x + $y & 1) & 1;
	}

	private function generateMaskNo($maskNo, $width, $frame)
	{
		$bitMask = array_fill(0, $width, array_fill(0, $width, 0));

		for ($y = 0; $y < $width; $y++) {
			for ($x = 0; $x < $width; $x++) {
				if (ord($frame[$y][$x]) & 128) {
					$bitMask[$y][$x] = 0;
				}
				else {
					$maskFunc = call_user_func(array($this, 'mask' . $maskNo), $x, $y);
					$bitMask[$y][$x] = $maskFunc == 0 ? 1 : 0;
				}
			}
		}

		return $bitMask;
	}

	static public function serial($bitFrame)
	{
		$codeArr = array();

		foreach ($bitFrame as $line) {
			$codeArr[] = join('', $line);
		}

		return gzcompress(join('
', $codeArr), 9);
	}

	static public function unserial($code)
	{
		$codeArr = array();
		$codeLines = explode('
', gzuncompress($code));

		foreach ($codeLines as $line) {
			$codeArr[] = str_split($line);
		}

		return $codeArr;
	}

	public function makeMaskNo($maskNo, $width, $s, &$d, $maskGenOnly = false)
	{
		$b = 0;
		$bitMask = array();
		$fileName = QR_CACHE_DIR . 'mask_' . $maskNo . DIRECTORY_SEPARATOR . 'mask_' . $width . '_' . $maskNo . '.dat';

		if (QR_CACHEABLE) {
			if (file_exists($fileName)) {
				$bitMask = self::unserial(file_get_contents($fileName));
			}
			else {
				$bitMask = $this->generateMaskNo($maskNo, $width, $s, $d);

				if (!file_exists(QR_CACHE_DIR . 'mask_' . $maskNo)) {
					mkdir(QR_CACHE_DIR . 'mask_' . $maskNo);
				}

				file_put_contents($fileName, self::serial($bitMask));
			}
		}
		else {
			$bitMask = $this->generateMaskNo($maskNo, $width, $s, $d);
		}

		if ($maskGenOnly) {
			return NULL;
		}

		$d = $s;

		for ($y = 0; $y < $width; $y++) {
			for ($x = 0; $x < $width; $x++) {
				if ($bitMask[$y][$x] == 1) {
					$d[$y][$x] = chr(ord($s[$y][$x]) ^ (int) $bitMask[$y][$x]);
				}

				$b += (int) (ord($d[$y][$x]) & 1);
			}
		}

		return $b;
	}

	public function makeMask($width, $frame, $maskNo, $level)
	{
		$masked = array_fill(0, $width, str_repeat(' ', $width));
		$this->makeMaskNo($maskNo, $width, $frame, $masked);
		$this->writeFormatInformation($width, $masked, $maskNo, $level);
		return $masked;
	}

	public function calcN1N3($length)
	{
		$demerit = 0;

		for ($i = 0; $i < $length; $i++) {
			if (5 <= $this->runLength[$i]) {
				$demerit += N1 + ($this->runLength[$i] - 5);
			}

			if ($i & 1) {
				if (3 <= $i && $i < $length - 2 && $this->runLength[$i] % 3 == 0) {
					$fact = (int) ($this->runLength[$i] / 3);
					if ($this->runLength[$i - 2] == $fact && $this->runLength[$i - 1] == $fact && $this->runLength[$i + 1] == $fact && $this->runLength[$i + 2] == $fact) {
						if ($this->runLength[$i - 3] < 0 || 4 * $fact <= $this->runLength[$i - 3]) {
							$demerit += N3;
						}
						else {
							if ($length <= $i + 3 || 4 * $fact <= $this->runLength[$i + 3]) {
								$demerit += N3;
							}
						}
					}
				}
			}
		}

		return $demerit;
	}

	public function evaluateSymbol($width, $frame)
	{
		$head = 0;
		$demerit = 0;

		for ($y = 0; $y < $width; $y++) {
			$head = 0;
			$this->runLength[0] = 1;
			$frameY = $frame[$y];

			if (0 < $y) {
				$frameYM = $frame[$y - 1];
			}

			for ($x = 0; $x < $width; $x++) {
				if (0 < $x && 0 < $y) {
					$b22 = ord($frameY[$x]) & ord($frameY[$x - 1]) & ord($frameYM[$x]) & ord($frameYM[$x - 1]);
					$w22 = ord($frameY[$x]) | ord($frameY[$x - 1]) | ord($frameYM[$x]) | ord($frameYM[$x - 1]);

					if (($b22 | $w22 ^ 1) & 1) {
						$demerit += N2;
					}
				}

				if ($x == 0 && ord($frameY[$x]) & 1) {
					$this->runLength[0] = -1;
					$head = 1;
					$this->runLength[$head] = 1;
				}
				else if (0 < $x) {
					if ((ord($frameY[$x]) ^ ord($frameY[$x - 1])) & 1) {
						$head++;
						$this->runLength[$head] = 1;
					}
					else {
						$this->runLength[$head]++;
					}
				}
			}

			$demerit += $this->calcN1N3($head + 1);
		}

		for ($x = 0; $x < $width; $x++) {
			$head = 0;
			$this->runLength[0] = 1;

			for ($y = 0; $y < $width; $y++) {
				if ($y == 0 && ord($frame[$y][$x]) & 1) {
					$this->runLength[0] = -1;
					$head = 1;
					$this->runLength[$head] = 1;
				}
				else if (0 < $y) {
					if ((ord($frame[$y][$x]) ^ ord($frame[$y - 1][$x])) & 1) {
						$head++;
						$this->runLength[$head] = 1;
					}
					else {
						$this->runLength[$head]++;
					}
				}
			}

			$demerit += $this->calcN1N3($head + 1);
		}

		return $demerit;
	}

	public function mask($width, $frame, $level)
	{
		$minDemerit = PHP_INT_MAX;
		$bestMaskNum = 0;
		$bestMask = array();
		$checked_masks = array(0, 1, 2, 3, 4, 5, 6, 7);

		if (QR_FIND_FROM_RANDOM !== false) {
			$howManuOut = 8 - QR_FIND_FROM_RANDOM % 9;

			for ($i = 0; $i < $howManuOut; $i++) {
				$remPos = rand(0, count($checked_masks) - 1);
				unset($checked_masks[$remPos]);
				$checked_masks = array_values($checked_masks);
			}
		}

		$bestMask = $frame;

		foreach ($checked_masks as $i) {
			$mask = array_fill(0, $width, str_repeat(' ', $width));
			$demerit = 0;
			$blacks = 0;
			$blacks = $this->makeMaskNo($i, $width, $frame, $mask);
			$blacks += $this->writeFormatInformation($width, $mask, $i, $level);
			$blacks = (int) (100 * $blacks / ($width * $width));
			$demerit = (int) ((int) (abs($blacks - 50) / 5) * N4);
			$demerit += $this->evaluateSymbol($width, $mask);

			if ($demerit < $minDemerit) {
				$minDemerit = $demerit;
				$bestMask = $mask;
				$bestMaskNum = $i;
			}
		}

		return $bestMask;
	}
}

define('N1', 3);
define('N2', 3);
define('N3', 40);
define('N4', 10);

?>