<?php

declare(strict_types=1);

/**
 * This file is part of CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace CodeIgniter\Images\Handlers;

use CodeIgniter\Images\Exceptions\ImageException;
use CodeIgniter\Images\Image;
use CodeIgniter\Images\ImageHandlerInterface;
use Config\Images;
use InvalidArgumentException;

/**
 * Base image handling implementation
 */
abstract class BaseHandler implements ImageHandlerInterface
{
    /**
     * Configuration settings.
     *
     * @var Images
     */
    protected $config;

    /**
     * The image/file instance
     *
     * @var Image
     */
    protected $image;

    /**
     * Whether the image file has been confirmed.
     *
     * @var bool
     */
    protected $verified = false;

    /**
     * Image width.
     *
     * @var int
     */
    protected $width = 0;

    /**
     * Image height.
     *
     * @var int
     */
    protected $height = 0;

    /**
     * File permission mask.
     *
     * @var int
     */
    protected $filePermissions = 0644;

    /**
     * X-axis.
     *
     * @var int|null
     */
    protected $xAxis = 0;

    /**
     * Y-axis.
     *
     * @var int|null
     */
    protected $yAxis = 0;

    /**
     * Master dimensioning.
     *
     * @var string
     */
    protected $masterDim = 'auto';

    /**
     * Default options for text watermarking.
     *
     * @var array
     */
    protected $textDefaults = [
        'fontPath'     => null,
        'fontSize'     => 16,
        'color'        => 'ffffff',
        'opacity'      => 1.0,
        'vAlign'       => 'bottom',
        'hAlign'       => 'center',
        'vOffset'      => 0,
        'hOffset'      => 0,
        'padding'      => 0,
        'withShadow'   => false,
        'shadowColor'  => '000000',
        'shadowOffset' => 3,
    ];

    /**
     * Image types with support for transparency.
     *
     * @var array
     */
    protected $supportTransparency = [
        IMAGETYPE_PNG,
        IMAGETYPE_WEBP,
    ];

    /**
     * Temporary image used by the different engines.
     *
     * @var resource|null
     */
    protected $resource;

    /**
     * Constructor.
     *
     * @param Images|null $config
     */
    public function __construct($config = null)
    {
        $this->config = $config ?? new Images();
    }

    /**
     * Sets another image for this handler to work on.
     * Keeps us from needing to continually instantiate the handler.
     *
     * @return $this
     */
    public function withFile(string $path)
    {
        // Clear out the old resource so that
        // it doesn't try to use a previous image
        $this->resource = null;
        $this->verified = false;

        $this->image = new Image($path, true);

        $this->image->getProperties(false);
        $this->width  = $this->image->origWidth;
        $this->height = $this->image->origHeight;

        return $this;
    }

    /**
     * Make the image resource object if needed
     *
     * @return void
     */
    abstract protected function ensureResource();

    /**
     * Returns the image instance.
     *
     * @return Image
     */
    public function getFile()
    {
        return $this->image;
    }

    /**
     * Verifies that a file has been supplied and it is an image.
     *
     * @return Image The image instance
     *
     * @throws ImageException
     */
    protected function image(): Image
    {
        if ($this->verified) {
            return $this->image;
        }

        // Verify withFile has been called
        if (empty($this->image)) {
            throw ImageException::forMissingImage();
        }

        // Verify the loaded image is an Image instance
        if (! $this->image instanceof Image) {
            throw ImageException::forInvalidPath();
        }

        // File::__construct has verified the file exists - make sure it is an image
        if (! is_int($this->image->imageType)) {
            throw ImageException::forFileNotSupported();
        }

        // Note that the image has been verified
        $this->verified = true;

        return $this->image;
    }

    /**
     * Returns the temporary image used during the image processing.
     * Good for extending the system or doing things this library
     * is not intended to do.
     *
     * @return resource
     */
    public function getResource()
    {
        $this->ensureResource();

        return $this->resource;
    }

    /**
     * Load the temporary image used during the image processing.
     * Some functions e.g. save() will only copy and not compress
     * your image otherwise.
     *
     * @return $this
     */
    public function withResource()
    {
        $this->ensureResource();

        return $this;
    }

    /**
     * Resize the image
     *
     * @param bool $maintainRatio If true, will get the closest match possible while keeping aspect ratio true.
     *
     * @return BaseHandler
     */
    public function resize(int $width, int $height, bool $maintainRatio = false, string $masterDim = 'auto')
    {
        // If the target width/height match the source, then we have nothing to do here.
        if ($this->image()->origWidth === $width && $this->image()->origHeight === $height) {
            return $this;
        }

        $this->width  = $width;
        $this->height = $height;

        if ($maintainRatio) {
            $this->masterDim = $masterDim;
            $this->reproportion();
        }

        return $this->_resize($maintainRatio);
    }

    /**
     * Crops the image to the desired height and width. If one of the height/width values
     * is not provided, that value will be set the appropriate value based on offsets and
     * image dimensions.
     *
     * @param int|null $x X-axis coord to start cropping from the left of image
     * @param int|null $y Y-axis coord to start cropping from the top of image
     *
     * @return $this
     */
    public function crop(?int $width = null, ?int $height = null, ?int $x = null, ?int $y = null, bool $maintainRatio = false, string $masterDim = 'auto')
    {
        $this->width  = $width;
        $this->height = $height;
        $this->xAxis  = $x;
        $this->yAxis  = $y;

        if ($maintainRatio) {
            $this->masterDim = $masterDim;
            $this->reproportion();
        }

        $result = $this->_crop();

        $this->xAxis = null;
        $this->yAxis = null;

        return $result;
    }

    /**
     * Changes the stored image type to indicate the new file format to use when saving.
     * Does not touch the actual resource.
     *
     * @param int $imageType A PHP imageType constant, e.g. https://www.php.net/manual/en/function.image-type-to-mime-type.php
     *
     * @return $this
     */
    public function convert(int $imageType)
    {
        $this->ensureResource();

        $this->image()->imageType = $imageType;

        return $this;
    }

    /**
     * Rotates the image on the current canvas.
     *
     * @return $this
     */
    public function rotate(float $angle)
    {
        // Allowed rotation values
        $degs = [
            90.0,
            180.0,
            270.0,
        ];

        if (! in_array($angle, $degs, true)) {
            throw ImageException::forMissingAngle();
        }

        // cast angle as an int, for our use
        $angle = (int) $angle;

        // Reassign the width and height
        if ($angle === 90 || $angle === 270) {
            $temp         = $this->height;
            $this->width  = $this->height;
            $this->height = $temp;
        }

        // Call the Handler-specific version.
        $this->_rotate($angle);

        return $this;
    }

    /**
     * Flattens transparencies, default white background
     *
     * @return $this
     */
    public function flatten(int $red = 255, int $green = 255, int $blue = 255)
    {
        $this->width  = $this->image()->origWidth;
        $this->height = $this->image()->origHeight;

        return $this->_flatten($red, $green, $blue);
    }

    /**
     * Handler-specific method to flattening an image's transparencies.
     *
     * @return $this
     *
     * @internal
     */
    abstract protected function _flatten(int $red = 255, int $green = 255, int $blue = 255);

    /**
     * Handler-specific method to handle rotating an image in 90 degree increments.
     *
     * @return mixed
     */
    abstract protected function _rotate(int $angle);

    /**
     * Flips an image either horizontally or vertically.
     *
     * @param string $dir Either 'vertical' or 'horizontal'
     *
     * @return $this
     */
    public function flip(string $dir = 'vertical')
    {
        $dir = strtolower($dir);

        if ($dir !== 'vertical' && $dir !== 'horizontal') {
            throw ImageException::forInvalidDirection($dir);
        }

        return $this->_flip($dir);
    }

    /**
     * Handler-specific method to handle flipping an image along its
     * horizontal or vertical axis.
     *
     * @return $this
     */
    abstract protected function _flip(string $direction);

    /**
     * Overlays a string of text over the image.
     *
     * Valid options:
     *
     *  - color         Text Color (hex number)
     *  - shadowColor   Color of the shadow (hex number)
     *  - hAlign        Horizontal alignment: left, center, right
     *  - vAlign        Vertical alignment: top, middle, bottom
     *  - hOffset
     *  - vOffset
     *  - fontPath
     *  - fontSize
     *  - shadowOffset
     *
     * @return $this
     */
    public function text(string $text, array $options = [])
    {
        $options                = array_merge($this->textDefaults, $options);
        $options['color']       = trim($options['color'], '# ');
        $options['shadowColor'] = trim($options['shadowColor'], '# ');

        $this->_text($text, $options);

        return $this;
    }

    /**
     * Handler-specific method for overlaying text on an image.
     *
     * @return void
     */
    abstract protected function _text(string $text, array $options = []);

    /**
     * Handles the actual resizing of the image.
     *
     * @return $this
     */
    abstract public function _resize(bool $maintainRatio = false);

    /**
     * Crops the image.
     *
     * @return $this
     */
    abstract public function _crop();

    /**
     * Return image width.
     *
     * @return int
     */
    abstract public function _getWidth();

    /**
     * Return the height of an image.
     *
     * @return int
     */
    abstract public function _getHeight();

    /**
     * Reads the EXIF information from the image and modifies the orientation
     * so that displays correctly in the browser. This is especially an issue
     * with images taken by smartphones who always store the image up-right,
     * but set the orientation flag to display it correctly.
     *
     * @param bool $silent If true, will ignore exceptions when PHP doesn't support EXIF.
     *
     * @return $this
     */
    public function reorient(bool $silent = false)
    {
        $orientation = $this->getEXIF('Orientation', $silent);

        return match ($orientation) {
            2       => $this->flip('horizontal'),
            3       => $this->rotate(180),
            4       => $this->rotate(180)->flip('horizontal'),
            5       => $this->rotate(270)->flip('horizontal'),
            6       => $this->rotate(270),
            7       => $this->rotate(90)->flip('horizontal'),
            8       => $this->rotate(90),
            default => $this,
        };
    }

    /**
     * Retrieve the EXIF information from the image, if possible. Returns
     * an array of the information, or null if nothing can be found.
     *
     * EXIF data is only supported fr JPEG & TIFF formats.
     *
     * @param string|null $key    If specified, will only return this piece of EXIF data.
     * @param bool        $silent If true, will not throw our own exceptions.
     *
     * @return mixed
     *
     * @throws ImageException
     */
    public function getEXIF(?string $key = null, bool $silent = false)
    {
        if (! function_exists('exif_read_data')) {
            if ($silent) {
                return null;
            }

            throw ImageException::forEXIFUnsupported(); // @codeCoverageIgnore
        }

        $exif = null; // default

        switch ($this->image()->imageType) {
            case IMAGETYPE_JPEG:
            case IMAGETYPE_TIFF_II:
                $exif = @exif_read_data($this->image()->getPathname());
                if ($key !== null && is_array($exif)) {
                    $exif = $exif[$key] ?? false;
                }
        }

        return $exif;
    }

    /**
     * Combine cropping and resizing into a single command.
     *
     * Supported positions:
     *  - top-left
     *  - top
     *  - top-right
     *  - left
     *  - center
     *  - right
     *  - bottom-left
     *  - bottom
     *  - bottom-right
     *
     * @return BaseHandler
     */
    public function fit(int $width, ?int $height = null, string $position = 'center')
    {
        $origWidth  = $this->image()->origWidth;
        $origHeight = $this->image()->origHeight;

        [$cropWidth, $cropHeight] = $this->calcAspectRatio($width, $height, $origWidth, $origHeight);

        if ($height === null) {
            $height = (int) ceil(($width / $cropWidth) * $cropHeight);
        }

        [$x, $y] = $this->calcCropCoords($cropWidth, $cropHeight, $origWidth, $origHeight, $position);

        return $this->crop($cropWidth, $cropHeight, (int) $x, (int) $y)->resize($width, $height);
    }

    /**
     * Calculate image aspect ratio.
     *
     * @param float|int      $width
     * @param float|int|null $height
     * @param float|int      $origWidth
     * @param float|int      $origHeight
     */
    protected function calcAspectRatio($width, $height = null, $origWidth = 0, $origHeight = 0): array
    {
        if (empty($origWidth) || empty($origHeight)) {
            throw new InvalidArgumentException('You must supply the parameters: origWidth, origHeight.');
        }

        // If $height is null, then we have it easy.
        // Calc based on full image size and be done.
        if ($height === null) {
            $height = ($width / $origWidth) * $origHeight;

            return [
                $width,
                (int) $height,
            ];
        }

        $xRatio = $width / $origWidth;
        $yRatio = $height / $origHeight;

        if ($xRatio > $yRatio) {
            return [
                $origWidth,
                (int) ($origWidth * $height / $width),
            ];
        }

        return [
            (int) ($origHeight * $width / $height),
            $origHeight,
        ];
    }

    /**
     * Based on the position, will determine the correct x/y coords to
     * crop the desired portion from the image.
     *
     * @param float|int $width
     * @param float|int $height
     * @param float|int $origWidth
     * @param float|int $origHeight
     * @param string    $position
     */
    protected function calcCropCoords($width, $height, $origWidth, $origHeight, $position): array
    {
        $position = strtolower($position);

        $x = $y = 0;

        switch ($position) {
            case 'top-left':
                $x = 0;
                $y = 0;
                break;

            case 'top':
                $x = floor(($origWidth - $width) / 2);
                $y = 0;
                break;

            case 'top-right':
                $x = $origWidth - $width;
                $y = 0;
                break;

            case 'left':
                $x = 0;
                $y = floor(($origHeight - $height) / 2);
                break;

            case 'center':
                $x = floor(($origWidth - $width) / 2);
                $y = floor(($origHeight - $height) / 2);
                break;

            case 'right':
                $x = ($origWidth - $width);
                $y = floor(($origHeight - $height) / 2);
                break;

            case 'bottom-left':
                $x = 0;
                $y = $origHeight - $height;
                break;

            case 'bottom':
                $x = floor(($origWidth - $width) / 2);
                $y = $origHeight - $height;
                break;

            case 'bottom-right':
                $x = ($origWidth - $width);
                $y = $origHeight - $height;
                break;
        }

        return [
            $x,
            $y,
        ];
    }

    /**
     * Get the version of the image library in use.
     *
     * @return string
     */
    abstract public function getVersion();

    /**
     * Saves any changes that have been made to file.
     *
     * Example:
     *    $image->resize(100, 200, true)
     *          ->save($target);
     *
     * @param non-empty-string|null $target
     *
     * @return bool
     */
    abstract public function save(?string $target = null, int $quality = 90);

    /**
     * Does the driver-specific processing of the image.
     *
     * @return mixed
     */
    abstract protected function process(string $action);

    /**
     * Provide access to the Image class' methods if they don't exist
     * on the handler itself.
     *
     * @return mixed
     */
    public function __call(string $name, array $args = [])
    {
        if (method_exists($this->image(), $name)) {
            return $this->image()->{$name}(...$args);
        }
    }

    /**
     * Re-proportion Image Width/Height
     *
     * When creating thumbs, the desired width/height
     * can end up warping the image due to an incorrect
     * ratio between the full-sized image and the thumb.
     *
     * This function lets us re-proportion the width/height
     * if users choose to maintain the aspect ratio when resizing.
     *
     * @return void
     */
    protected function reproportion()
    {
        if (($this->width === 0 && $this->height === 0) || $this->image()->origWidth === 0 || $this->image()->origHeight === 0 || (! ctype_digit((string) $this->width) && ! ctype_digit((string) $this->height)) || ! ctype_digit((string) $this->image()->origWidth) || ! ctype_digit((string) $this->image()->origHeight)) {
            return;
        }

        // Sanitize
        $this->width  = (int) $this->width;
        $this->height = (int) $this->height;

        if ($this->masterDim !== 'width' && $this->masterDim !== 'height') {
            if ($this->width > 0 && $this->height > 0) {
                $this->masterDim = ((($this->image()->origHeight / $this->image()->origWidth) - ($this->height / $this->width)) < 0) ? 'width' : 'height';
            } else {
                $this->masterDim = ($this->height === 0) ? 'width' : 'height';
            }
        } elseif (($this->masterDim === 'width' && $this->width === 0) || ($this->masterDim === 'height' && $this->height === 0)
        ) {
            return;
        }

        if ($this->masterDim === 'width') {
            $this->height = (int) ceil($this->width * $this->image()->origHeight / $this->image()->origWidth);
        } else {
            $this->width = (int) ceil($this->image()->origWidth * $this->height / $this->image()->origHeight);
        }
    }

    /**
     * Return image width.
     *
     * accessor for testing; not part of interface
     *
     * @return int
     */
    public function getWidth()
    {
        return ($this->resource !== null) ? $this->_getWidth() : $this->width;
    }

    /**
     * Return image height.
     *
     * accessor for testing; not part of interface
     *
     * @return int
     */
    public function getHeight()
    {
        return ($this->resource !== null) ? $this->_getHeight() : $this->height;
    }
}
