<?php
/**
 * ActivityPub Outbox Class
 *
 * @author Matthias Pfefferle
 */
class Activitypub_Outbox {
	/**
	 * Register routes
	 */
	public static function register_routes() {
		register_rest_route(
			'activitypub/1.0', '/users/(?P<id>\d+)/outbox', array(
				array(
					'methods'  => WP_REST_Server::READABLE,
					'callback' => array( 'Activitypub_Outbox', 'get' ),
					'args'     => self::request_parameters(),
				),
			)
		);
	}

	public static function get( $request ) {
		$author_id = $request->get_param( 'id' );
		$author    = get_user_by( 'ID', $author_id );

		if ( ! $author ) {
			return new WP_Error( 'rest_invalid_param', __( 'User not found', 'activitypub' ), array(
				'status' => 404, 'params' => array(
					'user_id' => __( 'User not found', 'activitypub' )
				)
			) );
		}

		$page = $request->get_param( 'page', 0 );

		/*
		 * Action triggerd prior to the ActivityPub profile being created and sent to the client
		 */
		do_action( 'activitypub_outbox_pre' );

		$json = new stdClass();

		$json->{'@context'} = array(
			'https://www.w3.org/ns/activitystreams',
			'https://w3id.org/security/v1',
		);

		$json->generator  = 'http://wordpress.org/?v=' . get_bloginfo_rss( 'version' );
		$json->actor      = get_author_posts_url( $author_id );
		$json->type       = 'OrderedCollectionPage';
		$json->partOf     = get_rest_url( null, "/activitypub/1.0/users/$author_id/outbox" ); // phpcs:ignore

		$count_posts      = wp_count_posts();
		$json->totalItems = $count_posts->publish;

		$posts = get_posts( array(
			'author' => $author_id,
			'offset' => $page,
		) );

		$json->first = add_query_arg( 'page', 0, $json->partOf );
		$json->last  = add_query_arg( 'page', ( $json->totalItems%10 )-1, $json->partOf );
		if ( $json->last < $page ) {
			$json->next  = add_query_arg( 'page', ++$page, $json->partOf );
		}

		foreach ( $posts as $post ) {
			$json->orderedItems[] = self::post_to_json( $post ); // phpcs:ignore
		}

		// filter output
		$json = apply_filters( 'activitypub_outbox_array', $json );

		/*
		 * Action triggerd after the ActivityPub profile has been created and sent to the client
		 */
		do_action( 'activitypub_outbox_post' );

		$response = new WP_REST_Response( $json, 200 );

		$response->header( 'Content-Type', 'application/activity-json' );

		return $response;
	}

	public static function post_to_json( $post ) {
		$json = new stdClass();

		$json->published = $post->post_date;
		$json->id        = $post->guid;
		$json->type      = 'Create';
		$json->actor     = 'https://mastodon.social/users/pfefferle';
		$json->to        = array( 'https://www.w3.org/ns/activitystreams#Public' );

		$json->object = array(
			'id'         => $post->guid,
			'type'       => 'Note',
			'published'  => $post->post_date,
			'to'         => array( 'https://www.w3.org/ns/activitystreams#Public' ),
			'content'    => $post->post_content,
			'contentMap' => array(
				strstr( get_locale(), '_', true ) => $post->post_content,
			),
		);

		return $json;
	}


	public static function request_parameters() {
		$params = array();

		$params['page'] = array(
			'type' => 'integer',
		);

		$params['id'] = array(
			'required' => true,
			'type' => 'integer',
		);

		return $params;
	}
}