<?php
/**
 * Adds support to Jetpack's Site Accelerator (Photon)
 *
 * @since 	2.2.0
 * @package Stackable
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

// Only when Jetpack's Photon is enabled.
if ( function_exists( 'jetpack_photon_url' ) ) {
	if ( ! function_exists( 'stackable_jetpack_photon_render_block_replace_style_images' ) ) {
		/**
		 * Replace the url with a Photon url.
		 *
		 * @param array $matches Matches returned by preg_replace_callback. These are urls.
		 *
		 * @return string The replacement string.
		 */
		function stackable_jetpack_photon_render_block_replace_style_images( $matches ) {
			return jetpack_photon_url( $matches[0] );
		}
	}

	if ( ! function_exists( 'stackable_jetpack_photon_render_block_replace_style' ) ) {
		/**
		 * Find all the image urls that needs ot be replaced with CDN urls.
		 *
		 * @param array $matches Matches returned by preg_replace_callback.
		 *
		 * @return string The replacement string.
		 */
		function stackable_jetpack_photon_render_block_replace_style( $matches ) {
			return preg_replace_callback( '/https?:[^;\}<]+.(jpg|gif|png)/i', 'stackable_jetpack_photon_render_block_replace_style_images', $matches[0] );
		}
	}

	if ( ! function_exists( 'stackable_jetpack_photon_render_block' ) ) {
		/**
		 * Replaces all image urls inside style tags into CDN tags.
		 *
		 * @param string $block_content The block output.
		 * @param array $block The block object being rendered.
		 *
		 * @return string The modified block output.
		 */
		function stackable_jetpack_photon_render_block( $block_content, $block ) {
			if ( $block_content === null ) {
				return $block_content;
			}

			// Only for Stackable blocks.
			if ( ! isset( $block['blockName'] ) || strpos( $block['blockName'], 'ugb/' ) === false ) {
				return $block_content;
			}

			// Just a quick check: Only change if there're images found in the style tag.
			if ( ! preg_match( '/<style(.*?)http\s?:(.*?).(jpg|png|gif)(.*?)<\/style/', $block_content ) ) {
				return $block_content;
			}

			// Replace photon images inside style tags.
			return preg_replace_callback( '/<style(.*?)<\/style/', 'stackable_jetpack_photon_render_block_replace_style', $block_content );
		}

		if ( is_frontend() ) {
			add_filter( 'render_block', 'stackable_jetpack_photon_render_block', 10, 2 );
		}
	}
}