<?php
/**
 * Handles all background proccessing interactions for the Envira Gallery plugin.
 *
 * @since 1.7.0
 *
 * @package Envira Gallery
 * @author  Envira Gallery Team <[email protected]>
 */

namespace Envira\Frontend;

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

	exit;

}

use Envira\Utils\Cropping;
use WP_REST_Response;

/**
 * Background Processing Class.
 *
 * @since 1.7.0
 */
class Background {

	/**
	 * API Namespace
	 *
	 * (default value: 'envira')
	 *
	 * @since 1.7.0
	 *
	 * @var string
	 * @access public
	 */
	public $domain = 'envira-background';

	/**
	 * API Version
	 *
	 * (default value: 'v1')
	 *
	 * @since 1.7.0
	 *
	 * @var string
	 * @access public
	 */
	public $version = 'v1';

	/**
	 * Holds API Request
	 *
	 * (default value: null)
	 *
	 * @var mixed
	 * @access public
	 */
	public $request = null;

	/**
	 * Class Constructor.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 */
	public function __construct() {

		// Actions.
		add_action( 'rest_api_init', [ $this, 'register_api_routes' ] );
	}

	/**
	 * Permission callback for background processing endpoints.
	 *
	 * @since 1.7.0
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return bool|WP_REST_Response
	 */
	public function verify_background_permission( $request ) {
		// Check if user is logged in.
		if ( ! is_user_logged_in() ) {
			return new WP_REST_Response( [ 'message' => __( 'You must be logged in to access this feature.', 'envira-gallery' ) ], 401 );
		}

		// Check if user can edit posts (basic capability for gallery management).
		$required_capability = apply_filters( 'envira_background_processing_capability', 'edit_posts' );
		if ( ! current_user_can( $required_capability ) ) {
			return new WP_REST_Response( [ 'message' => __( 'You do not have permission to access this feature.', 'envira-gallery' ) ], 403 );
		}

		// Validate the request using existing validation method.
		$valid = $this->validate_request( $request );
		if ( ! $valid ) {
			return new WP_REST_Response( [ 'message' => __( 'Invalid request. Security check failed.', 'envira-gallery' ) ], 403 );
		}

		return true;
	}

	/**
	 * Register API Routes used for background proccessing.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @return void
	 */
	public function register_api_routes() {

		$name    = $this->domain;
		$version = $this->version;

		register_rest_route(
			$name . '/' . $version,
			'/insert-gallery',
			[
				'methods'             => 'POST',
				'callback'            => [ $this, 'maybe_insert_gallery' ],
				'permission_callback' => [ $this, 'verify_background_permission' ],
			]
		);

		register_rest_route(
			$name . '/' . $version,
			'/insert-album',
			[
				'methods'             => 'POST',
				'callback'            => [ $this, 'maybe_insert_album' ],
				'permission_callback' => [ $this, 'verify_background_permission' ],
			]
		);

		register_rest_route(
			$name . '/' . $version,
			'/insert-image',
			[
				'methods'             => 'POST',
				'callback'            => [ $this, 'insert_image' ],
				'permission_callback' => [ $this, 'verify_background_permission' ],
			]
		);

		register_rest_route(
			$name . '/' . $version,
			'/crop-images',
			[
				'methods'             => 'POST',
				'callback'            => [ $this, 'crop_images' ],
				'permission_callback' => [ $this, 'verify_background_permission' ],
			]
		);

		register_rest_route(
			$name . '/' . $version,
			'/resize-image',
			[
				'methods'             => 'POST',
				'callback'            => [ $this, 'resize' ],
				'permission_callback' => [ $this, 'verify_background_permission' ],
			]
		);

		do_action( 'envira_gallery_routes', $name, $version );
	}

	/**
	 * Insert_gallery function.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param \WP_REST_Request $request Request.
	 * @return void
	 */
	public function maybe_insert_gallery( \WP_REST_Request $request ) {

		// Set the request.
		$this->request = $request;

		// Get the body.
		$body = $request->get_body_params();

		// Validate the request.
		$valid = $this->validate_request( $request );

		// Setup the ID Var.
		$post_id = '';

		// Return if request not valid.
		if ( ! $valid ) {

				return;

		}

		$defaults = [
			'ID'          => 0,
			'post_type'   => 'envira',
			'post_status' => 'publish',
			'post_title'  => '',
		];

		$post_args = wp_parse_args( $body['data']['gallery'], $defaults );

		if ( isset( $body['data']['id'] ) ) {

			$post_id = get_post( $body['data']['id'] );

		}

		if ( ! $post_id ) {

			$post = wp_insert_post( $post_args );

		} else {

			$post = wp_update_post( $post_args );

		}
		// make a request to insert images is.
		if ( is_array( $body['data']['images'] ) ) {

				$images = $body['data']['images'];

			foreach ( $images as $image => $data ) {

				// Build the Image Data.
				$image_data = [
					'gallery' => $post,
					'image'   => $data,
				];

				// Make the background request for inserting each image.
				$this->background_request( $image_data, 'insert-image' );

			}
		}

		die();
	}

	/**
	 * Background request to insert images into a gallery.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param \WP_REST_Request $request Request.
	 * @return void
	 */
	public function insert_image( \WP_REST_Request $request ) {

		global $wp_filesystem;

		if ( empty( $wp_filesystem ) ) {
			require_once ABSPATH . '/wp-admin/includes/file.php';
			WP_Filesystem();
		}

		// Set the request.
		$this->request = $request;
		// Get the body.
		$body = $request->get_body_params();

		// Validate the request.
		$valid = $this->validate_request( $request );

		// Return if request not valid.
		if ( ! $valid ) {

				return;

		}

		// Require if the function doesnt exist.
		if ( ! function_exists( 'wp_handle_sideload' ) ) {

			require_once ABSPATH . 'wp-admin/includes/file.php';
			include ABSPATH . 'wp-admin/includes/image.php';

		}

		$post_id = $body['data']['gallery'];
		$image   = $body['data']['image'];

		// Check that $post_id is a envira post_type.
		if ( 'envira' !== get_post_type( $post_id ) ) {

			return false;

		}

		$in_gallery = get_post_meta( $post_id, '_eg_in_gallery', true );

		if ( empty( $in_gallery ) ) {

			$in_gallery = [];

		}

		$gallery_data = get_post_meta( $post_id, '_eg_gallery_data', true );

		// If Gallery Data is emptyy prepare it.
		if ( empty( $gallery_data ) ) {

			$gallery_data = [];
		}

		// Set the File name from the API.
		$new_attachment = $image['title'];

		// Grab the Upload Directory.
		$upload_dir = wp_upload_dir();

		// Set the upload path.
		$upload_path = str_replace( '/', DIRECTORY_SEPARATOR, $upload_dir['path'] ) . DIRECTORY_SEPARATOR;

		// Decode the returned image.
		$image_upload = $wp_filesystem->put_contents( $upload_path . $new_attachment, $wp_filesystem->get_contents( $image['src'] ) );

		// Prep the new file.
		$file             = [];
		$file['error']    = '';
		$file['tmp_name'] = $upload_path . $new_attachment;
		$file['name']     = $new_attachment;
		$file['type']     = $gallery_data;
		$file['size']     = wp_filesize( $upload_path . $new_attachment );

		$file_return = wp_handle_sideload( $file, [ 'test_form' => false ] );

		// Setup the Attachment Data.
		$attachment = [
			'post_type'      => 'attachment',
			'post_mime_type' => 'image/jpeg',
			'post_title'     => preg_replace( '/\.[^.]+$/', '', basename( $new_attachment ) ),
			'post_content'   => '',
			'post_status'    => 'inherit',
			'post_parent'    => $post_id,
		];

		// Insert new attachment - check.
		$attachment_id = wp_insert_attachment( $attachment, $file_return['file'], $post_id );

		// Generate Attachment Metadata.
		$meta_data = wp_generate_attachment_metadata( $attachment_id, $file_return['file'] );

		// Update Attachments metadata.
		$update_data = wp_update_attachment_metadata( $attachment_id, $meta_data );

		// Update the attachment image post meta first.
		$has_slider = get_post_meta( $attachment_id, '_eg_has_gallery', true );

		if ( empty( $has_slider ) ) {

			$has_slider = [];

		}

		$has_slider[] = $post_id;

		// Now add the image to the slider for this particular post.
		$in_slider[] = $attachment_id;
		$slider_data = envira_prepare_gallery_data( $gallery_data, $attachment_id );

		// Update the slider data.
		update_post_meta( $attachment_id, '_eg_has_gallery', $has_slider );
		update_post_meta( $post_id, '_eg_in_gallery', $in_slider );
		update_post_meta( $post_id, '_eg_gallery_data', $slider_data );

		die();
	}

	/**
	 * Maybe insert album function.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param \WP_REST_Request $request Request.
	 * @return void
	 */
	public function maybe_insert_album( \WP_REST_Request $request ) {

		// Set the request.
		$this->request = $request;

		// Get the body.
		$body = $request->get_body_params();

		// Validate the request.
		$valid = $this->validate_request( $request );

		// Setup the ID Var.
		$post_id = '';

		// Return if request not valid.
		if ( ! $valid ) {

			die();

		}

		$defaults = [
			'ID'          => 0,
			'post_type'   => 'envira-album',
			'post_status' => 'publish',
			'post_title'  => '',
		];

		$post_args = wp_parse_args( $body['data']['album'], $defaults );

		if ( isset( $body['data']['id'] ) ) {

			$post_id = get_post( $body['data']['id'] );

		}

		if ( ! $post_id ) {

			$post = wp_insert_post( $post_args );

		} else {

			$post = wp_update_post( $post_args );

		}

		// make a request to insert images is.
		if ( is_array( $body['data']['galleries'] ) ) {

			$galleries = $body['data']['galleries'];

			foreach ( $galleries as $gallery => $data ) {

				// Build the Image Data.
				$image_data = [
					'album'     => $post,
					'galleries' => $data,
				];

				// Make the background request for inserting each image.
				$this->background_request( $image_data, 'insert-gallery' );

			}
		}

		die();
	}

	/**
	 * Crop and image via background request.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param \WP_REST_Request $request Request.
	 * @return void
	 */
	public function crop_images( \WP_REST_Request $request ) {

		// Set the request.
		$this->request = $request;

		// Get the body.
		$body = $request->get_body_params();

		// Validate the request.
		$valid = $this->validate_request( $request );

		// Return if request not valid.
		if ( ! $valid ) {

			die();

		}

		$data         = $body['data'];
		$gallery_data = _envira_get_gallery( $body['data']['id'] );
		$gallery_id   = $body['data']['id'];
		$images       = ! empty( $gallery_data['gallery'] ) ? $gallery_data['gallery'] : false;
		$align        = envira_get_config( 'crop_position', $gallery_data );

		// Loop through the images and crop them.
		if ( $images ) {

			foreach ( $images as $id => $item ) {

				// Get the full image attachment. If it does not return the data we need, skip over it.
				$image = wp_get_attachment_image_src( $id, 'full' );

				if ( ! is_array( $image ) ) {
					continue;
				}

				// Check the image is a valid URL.
				// Some plugins decide to strip the blog's URL.
				if ( ! filter_var( $image[0], FILTER_VALIDATE_URL ) ) {
					$image[0] = get_bloginfo( 'url' ) . '/' . $image[0];
				}

				// If the thumbnails option is checked, crop images accordingly.
				if ( isset( $gallery_data['config']['thumbnails'] ) && $gallery_data['config']['thumbnails'] ) {

					$args = [
						'align'   => $align,
						'width'   => apply_filters( 'envira_gallery_lightbox_thumbnail_width', $gallery_data['config']['thumbnails_width'], $gallery_data ),
						'height'  => apply_filters( 'envira_gallery_lightbox_thumbnail_height', $gallery_data['config']['thumbnails_height'], $gallery_data ),
						'quality' => 100,
						'retina'  => false,
					];

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

					$args['retina'] = true;

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

				}

				// If the mobile thumbnails option is checked, crop images accordingly.
				if ( isset( $gallery_data['config']['mobile_thumbnails'] ) && $gallery_data['config']['mobile_thumbnails'] ) {

					$args = [
						'align'   => $align,
						'width'   => apply_filters( 'envira_gallery_mobile_lightbox_thumbnail_width', $gallery_data['config']['mobile_thumbnails_width'], $gallery_data ),
						'height'  => apply_filters( 'envira_gallery_mobile_lightbox_thumbnail_height', $gallery_data['config']['mobile_thumbnails_height'], $gallery_data ),
						'quality' => 100,
						'retina'  => false,
					];

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

					$args['retina'] = true;

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );
				}

				// If the crop option is checked, crop images accordingly.
				if ( isset( $gallery_data['config']['crop'] ) && $gallery_data['config']['crop'] ) {

					$args = [
						'align'   => $align,
						'width'   => envira_get_config( 'crop_width', $gallery_data ),
						'height'  => envira_get_config( 'crop_height', $gallery_data ),
						'quality' => 100,
						'retina'  => false,
					];

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

					$args['retina'] = true;

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

				}

				// If the mobile option is checked, crop images accordingly.
				if ( isset( $gallery_data['config']['mobile'] ) && $gallery_data['config']['mobile'] ) {

					$args = [
						'align'   => $align,
						'width'   => envira_get_config( 'mobile_width', $gallery_data ),
						'height'  => envira_get_config( 'mobile_height', $gallery_data ),
						'quality' => 100,
						'retina'  => false,
					];

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

					$args['retina'] = true;

					$crop_data = [
						'args'       => $args,
						'gallery_id' => $gallery_id,
						'image_url'  => $image[0],
					];

					// Generate the cropped image.
					$this->background_request( $crop_data, 'resize-image' );

				}
			}
		}

		die();
	}

	/**
	 * Helper Request to resize images in the background.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param \WP_REST_Request $request Request.
	 * @return void
	 */
	public function resize( \WP_REST_Request $request ) {

		// Set the request.
		$this->request = $request;

		// Validate the request.
		$valid = $this->validate_request( $request );

		// Get the body.
		$body = $request->get_body_params();

		// Return if request not valid.
		if ( ! $valid ) {

			wp_send_json_error();

		}

		$defaults = [
			'url'             => '',
			'id'              => '',
			'gallery_id'      => '',
			'width'           => null,
			'height'          => null,
			'crop'            => true,
			'align'           => 'c',
			'quality'         => 100,
			'retina'          => false,
			'data'            => [],
			'force_overwrite' => false,
		];

		$args = wp_parse_args( $body['data']['args'], $defaults );

		$cropped_image = envira_resize_image( $body['data']['image_url'], $args['width'], $args['height'], true, $args['align'], $args['quality'], $args['retina'], null, $args['force_overwrite'] );

		if ( $cropped_image ) {
			wp_send_json_success( $cropped_image );

		} else {
			wp_send_json_error( $cropped_image );
		}
	}

	/**
	 * Validates the API request.
	 *
	 * @since 1.7.0
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return bool True if valid, false otherwise.
	 */
	public function validate_request( $request ) {

		$body = $request->get_body_params();

		if ( ! is_array( $body ) ) {

			return false;
		}

		// Verify the request is comming from the site.
		$site_url = get_home_url();

		if ( strpos( $body['site'], $site_url ) === false ) {

			return false;

		}

		$token = get_option( 'envira_rest_token' );

		// hash_equals() prevents timing-oracle attacks that allow brute-forcing the token character by character.
		if ( ! hash_equals( (string) $token, (string) $request->get_header( 'X-Envira-Token' ) ) ) {

			return false;

		}

		do_action( 'envira_gallery_validate_bp' );

		// All checks passed.
		return true;
	}

	/**
	 * Self generated token to validate background requests.
	 *
	 * @access public
	 * @return string
	 */
	public function generate_token() {

		$rest_token = wp_generate_password( 45, false, false );

		$hash = hash( 'sha256', $rest_token );

		update_option( 'envira_rest_token', $hash );

		return $hash;
	}

	/**
	 * Helper function to call background requests.
	 *
	 * @since 1.7.0
	 *
	 * @access public
	 * @param mixed $data Request Data.
	 * @param mixed $type Request Type.
	 * @return void
	 */
	public function background_request( $data, $type ) {

		// Bail if nothing set.
		if ( ! is_array( $data ) || ! isset( $type ) ) {
			return;
		}

		$name    = $this->domain;
		$version = $this->version;

		$rest_url = get_rest_url();
		$nonce    = wp_create_nonce( 'wp_rest' );
		$token    = get_option( 'envira_rest_token' );

		if ( ! $token ) {

			$token = $this->generate_token();
		}

		$defaults = [
			'data'  => $data,
			'site'  => get_home_url(),
			'nonce' => $nonce,
		];

		$body = wp_parse_args( $data, $defaults );

		$headers = [
			'X-Envira-Token' => $token,
		];

		// Generate the background request url.
		$url = trailingslashit( $rest_url ) . $name . '/' . $version . '/' . $type;

		$args = [
			'headers'    => $headers,
			'body'       => $body,
			'user-agent' => 'Envira/' . ENVIRA_VERSION,
			'timeout'    => 0.5,
			'blocking'   => false,
			'sslverify'  => apply_filters( 'envira_background_ssl_verify', false ),
		];

		$callit = wp_remote_post( $url, $args );
	}
}