<?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
	* @uses  wp_upload_dir()
	* @uses  image_resize_dimensions()
	* @uses  wp_get_image_editor()
	*
	* @return str|array
	*/

	if(!class_exists('Aq_Resize')){
		class Aq_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 === $upscale ) add_filter( 'image_resize_dimensions', array($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 );
				$dst_w= $dims[4];
				$dst_h= $dims[5];

				// 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 || ( true == $crop && false == $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 === $upscale ) remove_filter( 'image_resize_dimensions', array($this,'aq_upscale' ) );

				// Return the output.
				if( $single ){
					// str return.
					$image = $img_url;
				}
				else{
					// array return.
					$image = array (
						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 array(0,0,(int) $s_x,(int) $s_y,(int) $new_w,(int) $new_h,(int) $crop_w,(int) $crop_h );
			}
		}
	}

	if(!function_exists('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 aq_resize( $url, $width = null, $height = null, $crop = null, $single = true, $upscale = false ){
			$aq_resize = Aq_Resize::getInstance();
			return $aq_resize->process( $url, $width, $height, $crop, $single, $upscale );
		}
	}