<?php

/**
 * Title         : Aqua Resizer
 * Description   : Resizes WordPress images on the fly
 * Version       : 1.2.0
 * Author        : Syamil MJ
 * Author URI    : http://aquagraphite.com
 * License       : WTFPL - http://sam.zoy.org/wtfpl/
 * Documentation : https://github.com/sy4mil/Aqua-Resizer/
 *
 * @param string $url - (required) must be uploaded using wp media uploader
 * @param int $width - (required)
 * @param int $height - (optional)
 * @param bool $crop - (optional) default to soft crop
 * @param bool $single - (optional) returns an array if false
 * @return string|array
 * @uses  image_resize_dimensions()
 * @uses  wp_get_image_editor()
 *
 * @uses  wp_upload_dir()
 */

if (!defined('ABSPATH')) exit();

class Essential_Grid_Aqua_Resize
{
	/**
	 * The singleton instance
	 */
	static private $instance = null;

	/**
	 * No initialization allowed
	 */
	private function __construct()
	{
	}

	/**
	 * No cloning allowed
	 */
	private function __clone()
	{
	}

	/**
	 * For your custom default usage you may want to initialize an Aq_Resize object by yourself and then have own defaults
	 */
	static public function getInstance()
	{
		if (self::$instance == null) {
			self::$instance = new self;
		}

		return self::$instance;
	}

	/**
	 * Run, forest.
	 */
	public function process($url, $width = null, $height = null, $crop = null, $single = true, $upscale = false)
	{
		// Validate inputs.
		if (!$url || (!$width && !$height)) return false;

		// Caipt'n, ready to hook.
		if (true === $upscale) add_filter('image_resize_dimensions', [$this, 'aq_upscale'], 10, 6);

		// Define upload path & dir.
		$upload_info = wp_upload_dir();
		$upload_dir = $upload_info['basedir'];
		$upload_url = $upload_info['baseurl'];

		$http_prefix = "http://";
		$https_prefix = "https://";

		/* if the $url scheme differs from $upload_url scheme, make them match
		   if the schemes differe, images don't show up. */
		if (!strncmp($url, $https_prefix, strlen($https_prefix))) { 
			//if url begins with https:// make $upload_url begin with https:// as well
			$upload_url = str_replace($http_prefix, $https_prefix, $upload_url);
		} elseif (!strncmp($url, $http_prefix, strlen($http_prefix))) { 
			//if url begins with http:// make $upload_url begin with http:// as well
			$upload_url = str_replace($https_prefix, $http_prefix, $upload_url);
		}


		// Check if $img_url is local.
		if (false === strpos($url, $upload_url)) return false;

		// Define path of image.
		$rel_path = str_replace($upload_url, '', $url);
		$img_path = $upload_dir . $rel_path;

		// Check if img path exists, and is an image indeed.
		if (!file_exists($img_path) or !getimagesize($img_path)) return false;

		// Get image info.
		$info = pathinfo($img_path);
		$ext = $info['extension'];
		list($orig_w, $orig_h) = getimagesize($img_path);

		// Get image size after cropping.
		$dims = image_resize_dimensions($orig_w, $orig_h, $width, $height, $crop);
		if ($dims !== false && isset($dims[4]) && isset($dims[5])) {
			$dst_w = $dims[4];
			$dst_h = $dims[5];
		} else {
			$img_url = $url;
			$dst_w = $orig_w;
			$dst_h = $orig_h;
		}

		// Return the original image only if it exactly fits the needed measures.
		if (!$dims && (((null === $height && $orig_w == $width) xor (null === $width && $orig_h == $height)) xor ($height == $orig_h && $width == $orig_w))) {
			$img_url = $url;
			$dst_w = $orig_w;
			$dst_h = $orig_h;
		} else {
			// Use this to check if cropped image already exists, so we can return that instead.
			$suffix = "{$dst_w}x{$dst_h}";
			$dst_rel_path = str_replace('.' . $ext, '', $rel_path);
			$destfilename = "{$upload_dir}{$dst_rel_path}-{$suffix}.{$ext}";

			if (!$dims || ($crop && !$upscale && ($dst_w < $width || $dst_h < $height))) {
				// Can't resize, so return false saying that the action to do could not be processed as planned.
				return false;
			} // Else check if cache exists.
			elseif (file_exists($destfilename) && getimagesize($destfilename)) {
				$img_url = "{$upload_url}{$dst_rel_path}-{$suffix}.{$ext}";
			} // Else, we resize the image and return the new resized image url.
			else {

				$editor = wp_get_image_editor($img_path);

				if (is_wp_error($editor) || is_wp_error($editor->resize($width, $height, $crop)))
					return false;

				$resized_file = $editor->save();

				if (!is_wp_error($resized_file)) {
					$resized_rel_path = str_replace($upload_dir, '', $resized_file['path']);
					$img_url = $upload_url . $resized_rel_path;
				} else {
					return false;
				}

			}
		}

		// Okay, leave the ship.
		if (true === $upscale) remove_filter('image_resize_dimensions', [$this, 'aq_upscale']);

		// Return the output.
		if ($single) {
			// str return.
			$image = $img_url;
		} else {
			// array return.
			$image = [
				0 => $img_url,
				1 => $dst_w,
				2 => $dst_h
			];
		}

		return $image;
	}

	/**
	 * Callback to overwrite WP computing of thumbnail measures
	 */
	function aq_upscale($default, $orig_w, $orig_h, $dest_w, $dest_h, $crop)
	{
		if (!$crop) return null; // Let the wordPress default function handle this.

		// Here is the point we allow to use larger image size than the original one.
		$aspect_ratio = $orig_w / $orig_h;
		$new_w = $dest_w;
		$new_h = $dest_h;

		if (!$new_w) {
			$new_w = intval($new_h * $aspect_ratio);
		}

		if (!$new_h) {
			$new_h = intval($new_w / $aspect_ratio);
		}

		$size_ratio = max($new_w / $orig_w, $new_h / $orig_h);

		$crop_w = round($new_w / $size_ratio);
		$crop_h = round($new_h / $size_ratio);

		$s_x = floor(($orig_w - $crop_w) / 2);
		$s_y = floor(($orig_h - $crop_h) / 2);

		return [0, 0, (int)$s_x, (int)$s_y, (int)$new_w, (int)$new_h, (int)$crop_w, (int)$crop_h];
	}
}

if (!function_exists('esg_aq_resize')) {
	/**
	 * This is just a tiny wrapper function for the class above so that there is no
	 * need to change any code in your own WP themes. Usage is still the same :)
	 */
	function esg_aq_resize($url, $width = null, $height = null, $crop = null, $single = true, $upscale = false)
	{
		$aq_resize = Essential_Grid_Aqua_Resize::getInstance();
		$img = $aq_resize->process($url, $width, $height, $crop, $single, $upscale);
		if ($single) {
			return ($img == '') ? $url : $img;
		} else {
			return (empty($img)) ? $url : $img;
		}
	}
}
