Cloudflare Image API mock WordPress plugin

cloudflare-image-server.php

<?php
/**
 * Plugin Name: Cloudflare Image API Mock
 * Description: Replicate Cloudflare Image API functionality locally.
 *
 * IMPORTANT: The code below shouldn't be used on production since the
 * image path resolution is vulnerable to directory traversal attacks.
 */

add_action(
	'init',
	function() {
		// https://example.com/cdn-cgi/image/abc123/quality=90,width=120/wp-content/uploads/sites/11/2024/11/example.jpeg
		add_rewrite_rule( 'cdn-cgi/image/([^/]+)/([^/]+)/?(.+)/?$', 'index.php?cf_image_account_id=$matches[1]&cf_image_options=$matches[2]&cf_image_url=$matches[3]', 'top' );
	}
);

add_filter(
	'query_vars',
	function( $query_vars ) {
		return array_merge(
			$query_vars,
			[ 'cf_image_account_id', 'cf_image_options', 'cf_image_url' ]
		);
	}
);

add_action(
	'template_redirect',
	function () {
		$account_id = get_query_var( 'cf_image_account_id' );

		if ( ! $account_id ) {
			return;
		}

		$options = array_reduce(
			explode( ',', urldecode( get_query_var( 'cf_image_options' ) ) ),
			function( $carry, $item ) {
				$pair = explode( '=', $item );
				$carry[ $pair[0] ] = is_numeric( $pair[1] ) ? (int) $pair[1] : $pair[1];
				return $carry;
			},
			[]
		);

		$options = wp_parse_args(
			$options,
			[
				'quality' => null,
				'width' => null,
				'height' => null,
			]
		);

		$image_url = urldecode( get_query_var( 'cf_image_url' ) );
		$image_path = sprintf( '%s/%s', dirname( WP_CONTENT_DIR ), ltrim( $image_url, '/' ) ); // TODO: Prevent directory traversal attacks.

		if ( is_readable( $image_path ) ) {
			$image = wp_get_image_editor( $image_path );

			if ( $options['width'] || $options['height'] ) {
				$image->resize( $options['width'], $options['height'], true );
			}

			$image->stream();
			exit;
		}
	}
);