<?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() {}

		/**
		 * Cache uploads dir.
		 */
		private $upload_info = array();

		/**
		 * 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.
			if ( !empty( $this->upload_info ) ) {
				$upload_info = $this->upload_info;
			} else {
				$upload_info = $this->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;
			$img_dim = getimagesize( $img_path );

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

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

			// 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 );
	}
}