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<?php

namespace PhpOffice\PhpSpreadsheet\Worksheet;

use GdImage;

use PhpOffice\PhpSpreadsheet\Exception;

use PhpOffice\PhpSpreadsheet\Shared\File;

class MemoryDrawing extends BaseDrawing

{

    // Rendering functions

    const RENDERING_DEFAULT = 'imagepng';

    const RENDERING_PNG = 'imagepng';

    const RENDERING_GIF = 'imagegif';

    const RENDERING_JPEG = 'imagejpeg';

    // MIME types

    const MIMETYPE_DEFAULT = 'image/png';

    const MIMETYPE_PNG = 'image/png';

    const MIMETYPE_GIF = 'image/gif';

    const MIMETYPE_JPEG = 'image/jpeg';

    const SUPPORTED_MIME_TYPES = [

        self::MIMETYPE_GIF,

        self::MIMETYPE_JPEG,

        self::MIMETYPE_PNG,

    ];

    /**

     * Image resource.

     */

    private null|GdImage $imageResource = null;

    /**

     * Rendering function.

     *

     * @var callable-string

     */

    private string $renderingFunction;

    /**

     * Mime type.

     */

    private string $mimeType;

    /**

     * Unique name.

     */

    private string $uniqueName;

    /**

     * Create a new MemoryDrawing.

     */

    public function __construct()

    {

        // Initialise values

        $this->renderingFunction = self::RENDERING_DEFAULT;

        $this->mimeType = self::MIMETYPE_DEFAULT;

        $this->uniqueName = md5(mt_rand(0, 9999) . time() . mt_rand(0, 9999));

        // Initialize parent

        parent::__construct();

    }

    public function __destruct()

    {

        if ($this->imageResource) {

            @imagedestroy($this->imageResource);

            $this->imageResource = null;

        }

        $this->worksheet = null;

    }

    public function __clone()

    {

        parent::__clone();

        $this->cloneResource();

    }

    private function cloneResource(): void

    {

        if (!$this->imageResource) {

            return;

        }

        $width = (int) imagesx($this->imageResource);

        $height = (int) imagesy($this->imageResource);

        if (imageistruecolor($this->imageResource)) {

            $clone = imagecreatetruecolor($width, $height);

            if (!$clone) {

                throw new Exception('Could not clone image resource');

            }

            imagealphablending($clone, false);

            imagesavealpha($clone, true);

        } else {

            $clone = imagecreate($width, $height);

            if (!$clone) {

                throw new Exception('Could not clone image resource');

            }

            // If the image has transparency...

            $transparent = imagecolortransparent($this->imageResource);

            if ($transparent >= 0) {

                // Starting with Php8.0, next function throws rather than return false

                $rgb = imagecolorsforindex($this->imageResource, $transparent);

                imagesavealpha($clone, true);

                $color = imagecolorallocatealpha($clone, $rgb['red'], $rgb['green'], $rgb['blue'], $rgb['alpha']);

                if ($color === false) {

                    throw new Exception('Could not get image alpha color');

                }

                imagefill($clone, 0, 0, $color);

            }

        }

        //Create the Clone!!

        imagecopy($clone, $this->imageResource, 0, 0, 0, 0, $width, $height);

        $this->imageResource = $clone;

    }

    /**

     * @param resource $imageStream Stream data to be converted to a Memory Drawing

     *

     * @throws Exception

     */

    public static function fromStream($imageStream): self

    {

        $streamValue = stream_get_contents($imageStream);

        if ($streamValue === false) {

            throw new Exception('Unable to read data from stream');

        }

        return self::fromString($streamValue);

    }

    /**

     * @param string $imageString String data to be converted to a Memory Drawing

     *

     * @throws Exception

     */

    public static function fromString(string $imageString): self

    {

        $gdImage = @imagecreatefromstring($imageString);

        if ($gdImage === false) {

            throw new Exception('Value cannot be converted to an image');

        }

        $mimeType = self::identifyMimeType($imageString);

        if (imageistruecolor($gdImage) || imagecolortransparent($gdImage) >= 0) {

            imagesavealpha($gdImage, true);

        }

        $renderingFunction = self::identifyRenderingFunction($mimeType);

        $drawing = new self();

        $drawing->setImageResource($gdImage);

        $drawing->setRenderingFunction($renderingFunction);

        $drawing->setMimeType($mimeType);

        return $drawing;

    }

    /** @return callable-string */

    private static function identifyRenderingFunction(string $mimeType): string

    {

        return match ($mimeType) {

            self::MIMETYPE_PNG => self::RENDERING_PNG,

            self::MIMETYPE_JPEG => self::RENDERING_JPEG,

            self::MIMETYPE_GIF => self::RENDERING_GIF,

            default => self::RENDERING_DEFAULT,

        };

    }

    /**

     * @throws Exception

     */

    private static function identifyMimeType(string $imageString): string

    {

        $temporaryFileName = File::temporaryFilename();

        file_put_contents($temporaryFileName, $imageString);

        $mimeType = self::identifyMimeTypeUsingExif($temporaryFileName);

        if ($mimeType !== null) {

            unlink($temporaryFileName);

            return $mimeType;

        }

        $mimeType = self::identifyMimeTypeUsingGd($temporaryFileName);

        if ($mimeType !== null) {

            unlink($temporaryFileName);

            return $mimeType;

        }

        unlink($temporaryFileName);

        return self::MIMETYPE_DEFAULT;

    }

    private static function identifyMimeTypeUsingExif(string $temporaryFileName): ?string

    {

        if (function_exists('exif_imagetype')) {

            $imageType = @exif_imagetype($temporaryFileName);

            $mimeType = ($imageType) ? image_type_to_mime_type($imageType) : null;

            return self::supportedMimeTypes($mimeType);

        }

        return null;

    }

    private static function identifyMimeTypeUsingGd(string $temporaryFileName): ?string

    {

        if (function_exists('getimagesize')) {

            $imageSize = @getimagesize($temporaryFileName);

            if (is_array($imageSize)) {

                $mimeType = $imageSize['mime'];

                return self::supportedMimeTypes($mimeType);

            }

        }

        return null;

    }

    private static function supportedMimeTypes(?string $mimeType = null): ?string

    {

        if (in_array($mimeType, self::SUPPORTED_MIME_TYPES, true)) {

            return $mimeType;

        }

        return null;

    }

    /**

     * Get image resource.

     */

    public function getImageResource(): ?GdImage

    {

        return $this->imageResource;

    }

    /**

     * Set image resource.

     *

     * @return $this

     */

    public function setImageResource(?GdImage $value): static

    {

        $this->imageResource = $value;

        if ($this->imageResource !== null) {

            // Get width/height

            $this->width = (int) imagesx($this->imageResource);

            $this->height = (int) imagesy($this->imageResource);

        }

        return $this;

    }

    /**

     * Get rendering function.

     *

     * @return callable-string

     */

    public function getRenderingFunction(): string

    {

        return $this->renderingFunction;

    }

    /**

     * Set rendering function.

     *

     * @param callable-string $value see self::RENDERING_*

     *

     * @return $this

     */

    public function setRenderingFunction(string $value): static

    {

        $this->renderingFunction = $value;

        return $this;

    }

    /**

     * Get mime type.

     */

    public function getMimeType(): string

    {

        return $this->mimeType;

    }

    /**

     * Set mime type.

     *

     * @param string $value see self::MIMETYPE_*

     *

     * @return $this

     */

    public function setMimeType(string $value): static

    {

        $this->mimeType = $value;

        return $this;

    }

    /**

     * Get indexed filename (using image index).

     */

    public function getIndexedFilename(): string

    {

        $extension = strtolower($this->getMimeType());

        $extension = explode('/', $extension);

        $extension = $extension[1];

        return $this->uniqueName . $this->getImageIndex() . '.' . $extension;

    }

    /**

     * Get hash code.

     *

     * @return string Hash code

     */

    public function getHashCode(): string

    {

        return md5(

            $this->renderingFunction

            . $this->mimeType

            . $this->uniqueName

            . parent::getHashCode()

            . __CLASS__

        );

    }

}