<?php
/**
 * ActivityPub Interaction Controller file.
 *
 * @package Activitypub
 */

namespace Activitypub\Rest;

use Activitypub\Activity\Activity;
use Activitypub\Collection\Actors;
use Activitypub\Http;

use function Activitypub\user_can_activitypub;

/**
 * Interaction Controller.
 */
class Interaction_Controller extends \WP_REST_Controller {
	/**
	 * The namespace of this controller's route.
	 *
	 * @var string
	 */
	protected $namespace = ACTIVITYPUB_REST_NAMESPACE;

	/**
	 * The base of this controller's route.
	 *
	 * @var string
	 */
	protected $rest_base = 'interactions';

	/**
	 * Register routes.
	 */
	public function register_routes() {
		\register_rest_route(
			$this->namespace,
			'/' . $this->rest_base,
			array(
				array(
					'methods'             => \WP_REST_Server::READABLE,
					'callback'            => array( $this, 'get_item' ),
					'permission_callback' => '__return_true',
					'args'                => array(
						'uri'    => array(
							'description'       => 'The URI or webfinger ID of the object to interact with.',
							'type'              => 'string',
							'required'          => true,
							'sanitize_callback' => array( $this, 'sanitize_uri' ),
						),
						'intent' => array(
							'description' => 'The intent of the interaction, e.g., follow, reply, import.',
							'type'        => 'string',
							'enum'        => array_map( 'Activitypub\camel_to_snake_case', Activity::TYPES ),
						),
					),
				),
			)
		);
	}

	/**
	 * Sanitize the URI parameter.
	 *
	 * @param string $uri The URI or webfinger ID of the object to interact with.
	 *
	 * @return string Sanitized URI.
	 */
	public function sanitize_uri( $uri ) {
		// Remove "acct:" prefix if present.
		if ( str_starts_with( $uri, 'acct:' ) ) {
			$uri = \substr( $uri, 5 );
		}

		// Remove "@" prefix if present.
		$uri = \ltrim( $uri, '@' );

		if ( is_email( $uri ) ) {
			return \sanitize_text_field( $uri );
		}

		return \sanitize_url( $uri );
	}

	/**
	 * Retrieves the interaction URL for a given URI.
	 *
	 * @param \WP_REST_Request $request The request object.
	 *
	 * @return \WP_REST_Response Response object on success, dies on failure.
	 */
	public function get_item( $request ) {
		$uri          = $request->get_param( 'uri' );
		$intent       = $request->get_param( 'intent' );
		$redirect_url = '';
		$object       = Http::get_remote_object( $uri );

		if ( \is_wp_error( $object ) || ! isset( $object['type'] ) ) {
			// Use wp_die as this can be called from the front-end. See https://github.com/Automattic/wordpress-activitypub/pull/1149/files#r1915297109.
			\wp_die(
				esc_html__( 'The URL is not supported!', 'activitypub' ),
				'',
				array(
					'response'  => 400,
					'back_link' => true,
				)
			);
		}

		if ( ! empty( $object['id'] ) ) {
			$uri = \esc_url( $object['id'] );
		}

		// Prepare URL parameter.
		$url_param = \rawurlencode( $uri );

		switch ( $object['type'] ) {
			case 'Group':
			case 'Person':
			case 'Service':
			case 'Application':
			case 'Organization':
				if ( \get_option( 'activitypub_following_ui', '0' ) ) {
					if ( user_can_activitypub( \get_current_user_id() ) ) {
						$redirect_url = \admin_url( 'users.php?page=activitypub-following-list&resource=' . $url_param );
					} elseif ( user_can_activitypub( Actors::BLOG_USER_ID ) ) {
						$redirect_url = \admin_url( 'options-general.php?page=activitypub&tab=following&resource=' . $url_param );
					}
				}

				/**
				 * Filters the URL used for following an ActivityPub actor.
				 *
				 * @param string $redirect_url The URL to redirect to.
				 * @param string $uri          The URI of the actor to follow.
				 * @param array  $object       The full actor object data.
				 * @param string $intent       The intent of the interaction.
				 */
				$redirect_url = \apply_filters( 'activitypub_interactions_follow_url', $redirect_url, $uri, $object, $intent );
				break;
			case 'Collection':
			case 'CollectionPage':
			case 'OrderedCollection':
			case 'OrderedCollectionPage':
				if ( \get_option( 'activitypub_following_ui', '0' ) ) {
					$redirect_url = \admin_url( 'admin.php?import=starter-kit&url=' . $url_param );
				}

				/**
				 * Filters the URL used for importing a Starter Kit collection.
				 *
				 * @param string $redirect_url The URL to redirect to.
				 * @param string $uri          The URI of the collection to import.
				 * @param array  $object       The full collection object data.
				 * @param string $intent       The intent of the interaction.
				 */
				$redirect_url = \apply_filters( 'activitypub_interactions_starter_kit_url', $redirect_url, $uri, $object, $intent );
				break;
			default:
				$redirect_url = \admin_url( 'post-new.php?in_reply_to=' . $url_param );

				/**
				 * Filters the URL used for replying to an ActivityPub object.
				 *
				 * By default, this redirects to the WordPress post editor with the in_reply_to parameter set.
				 *
				 * @param string $redirect_url The URL to redirect to.
				 * @param string $uri          The URI of the object to reply to.
				 * @param array  $object       The full object data being replied to.
				 * @param string $intent       The intent of the interaction.
				 */
				$redirect_url = \apply_filters( 'activitypub_interactions_reply_url', $redirect_url, $uri, $object, $intent );
		}

		/**
		 * Filters the redirect URL.
		 *
		 * This filter runs after the type-specific filters and allows for final modifications
		 * to the interaction URL regardless of the object type.
		 *
		 * @param string $redirect_url The URL to redirect to.
		 * @param string $uri          The URI of the object.
		 * @param array  $object       The object being interacted with.
		 * @param string $intent       The intent of the interaction.
		 */
		$redirect_url = \apply_filters( 'activitypub_interactions_url', $redirect_url, $uri, $object, $intent );

		// Check if hook is implemented.
		if ( ! $redirect_url ) {
			// Use wp_die as this can be called from the front-end. See https://github.com/Automattic/wordpress-activitypub/pull/1149/files#r1915297109.
			\wp_die(
				esc_html__( 'This Interaction type is not supported yet!', 'activitypub' ),
				'',
				array(
					'response'  => 400,
					'back_link' => true,
				)
			);
		}

		return new \WP_REST_Response( null, 302, array( 'Location' => $redirect_url ) );
	}
}
