<?php


namespace Zxing;

/**
 * This class is used to help decode images from files which arrive as GD Resource
 * It does not support rotation.
 *
 *
 *
 */
final class IMagickLuminanceSource extends LuminanceSource {

    public   $luminances;
    private  $dataWidth;
    private  $dataHeight;
    private  $left;
    private  $top;
    private  $image;



    public function __construct($image,
                                $dataWidth,
                                $dataHeight,
                                $left=null,
                                $top=null,
                                $width=null,
                                $height=null) {
        if(!$left&&!$top&&!$width&&!$height){
            $this->_IMagickLuminanceSource($image,$dataWidth,$dataHeight);
            return;
        }
        parent::__construct($width, $height);
        if ($left + $width > $dataWidth || $top + $height > $dataHeight) {
            throw new \InvalidArgumentException("Crop rectangle does not fit within image data.");
        }
        $this->luminances = $image;
        $this->dataWidth = $dataWidth;
        $this->dataHeight = $dataHeight;
        $this->left = $left;
        $this->top = $top;
    }

    public function _IMagickLuminanceSource($image, $width, $height)
    {
        parent::__construct($width, $height);

        $this->dataWidth = $width;
        $this->dataHeight = $height;
        $this->left = 0;
        $this->top = 0;
        $this->image = $image;


// In order to measure pure decoding speed, we convert the entire image to a greyscale array
// up front, which is the same as the Y channel of the YUVLuminanceSource in the real app.
        $this->luminances = [];

        $image->setImageColorspace (\Imagick::COLORSPACE_GRAY);
       // $image->newPseudoImage(0, 0, "magick:rose");
        $pixels = $image->exportImagePixels(1, 1, $width, $height, "RGB", \Imagick::COLORSPACE_RGB);

        $array = [];
        $rgb = [];


            for($i=0;$i<count($pixels);$i+=3){

                $r = $pixels[$i]& 0xff;
                $g = $pixels[$i+1]& 0xff;
                $b = $pixels[$i+2]& 0xff;
                if ($r == $g && $g == $b) {
// Image is already greyscale, so pick any channel.

                    $this->luminances[] = $r;//(($r + 128) % 256) - 128;
                } else {
// Calculate luminance cheaply, favoring green.
                    $this->luminances[] = ($r+2*$g+$b)/4;//(((($r + 2 * $g + $b) / 4) + 128) % 256) - 128;
                }
            }



    }

//@Override
    public function getRow($y, $row=null) {
        if ($y < 0 || $y >= $this->getHeight()) {
            throw new \InvalidArgumentException("Requested row is outside the image: " + y);
        }
        $width = $this->getWidth();
        if ($row == null || count($row) < $width) {
            $row = [];
        }
        $offset = ($y + $this->top) * $this->dataWidth + $this->left;
        $row = arraycopy($this->luminances,$offset, $row, 0, $width);
        return $row;
    }

//@Override
    public function getMatrix() {
        $width = $this->getWidth();
        $height = $this->getHeight();

// If the caller asks for the entire underlying image, save the copy and give them the
// original data. The docs specifically warn that result.length must be ignored.
        if ($width == $this->dataWidth && $height == $this->dataHeight) {
            return $this->luminances;
        }

        $area = $width * $height;
        $matrix = [];
        $inputOffset = $this->top * $this->dataWidth + $this->left;

// If the width matches the full width of the underlying data, perform a single copy.
        if ($width == $this->dataWidth) {
            $matrix = arraycopy($this->luminances, $inputOffset, $matrix, 0, $area);
            return $matrix;
        }

// Otherwise copy one cropped row at a time.
        $rgb = $this->luminances;
        for ($y = 0; $y < $height; $y++) {
            $outputOffset = $y * $width;
            $matrix = arraycopy($rgb, $inputOffset, $matrix, $outputOffset, $width);
            $inputOffset += $this->dataWidth;
        }
        return $matrix;
    }

//@Override
    public function isCropSupported() {
        return true;
    }

//@Override
    public function crop($left, $top, $width, $height) {
        return new GDLuminanceSource($this->luminances,
            $this->dataWidth,
            $this->dataHeight,
            $this->left + $left,
            $this->top + $top,
            $width,
            $height);
    }

}
