<?php
/**
 * The author Gralus publishes articles under: one of the site's existing users, chosen in Gralus. Gralus can fill in
 * that user's profile (bio, website, job title, LinkedIn, photo), so articles carry a real, described author. Users are
 * never created or deleted, and nothing but the chosen user's profile fields changes.
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class Gralus_Author {
	const OPTION     = 'gralus_author_id';
	const JOB_META   = 'gralus_job_title';
	const PHOTO_META = 'gralus_avatar_id';
	/** Yoast SEO reads LinkedIn from this user meta key for the author's sameAs. */
	const LINKEDIN_META = 'linkedin';

	public static function register_routes() {
		$auth = array( 'Gralus_Connection', 'verify_request' );
		register_rest_route( Gralus_Rest::NS, '/authors', array( 'methods' => 'GET', 'callback' => array( __CLASS__, 'list_authors' ), 'permission_callback' => $auth ) );
		register_rest_route( Gralus_Rest::NS, '/author', array( 'methods' => 'POST', 'callback' => array( __CLASS__, 'save' ), 'permission_callback' => $auth ) );
	}

	/** The chosen author when that user can still write posts, else the first administrator. */
	public static function author_id() {
		$chosen = (int) get_option( self::OPTION, 0 );
		if ( $chosen && user_can( $chosen, 'edit_posts' ) ) {
			return $chosen;
		}
		$admins = get_users( array( 'role' => 'administrator', 'number' => 1, 'orderby' => 'ID', 'fields' => 'ID' ) );
		return $admins ? (int) $admins[0] : 0;
	}

	/** One user as Gralus shows it. No email addresses or logins leave the site. */
	private static function describe( WP_User $u ) {
		$photo = (int) get_user_meta( $u->ID, self::PHOTO_META, true );
		return array(
			'id'       => (int) $u->ID,
			'name'     => $u->display_name,
			'roles'    => array_values( $u->roles ),
			'bio'      => (string) get_user_meta( $u->ID, 'description', true ),
			'url'      => (string) $u->user_url,
			'jobTitle' => (string) get_user_meta( $u->ID, self::JOB_META, true ),
			'linkedin' => (string) get_user_meta( $u->ID, self::LINKEDIN_META, true ),
			'avatar'   => (string) get_avatar_url( $u->ID, array( 'size' => 192 ) ),
			'ownPhoto' => $photo > 0 && wp_attachment_is_image( $photo ),
			'posts'    => (int) count_user_posts( $u->ID, 'post', true ),
			'profile'  => get_author_posts_url( $u->ID ),
		);
	}

	/** GET /authors: the users who can write posts, and which one Gralus publishes under. */
	public static function list_authors() {
		$users = get_users(
			array(
				'capability' => 'edit_posts',
				'number'     => 50,
				'orderby'    => 'post_count',
				'order'      => 'DESC',
			)
		);
		return array(
			'chosen'  => (int) get_option( self::OPTION, 0 ),
			'current' => self::author_id(),
			'users'   => array_map( array( __CLASS__, 'describe' ), $users ),
		);
	}

	/**
	 * POST /author: { id, bio?, url?, jobTitle?, linkedin?, photoId? }. Makes that user the author of new articles and
	 * updates only the fields sent. photoId is a Media Library image (uploaded through /media); 0 removes the photo.
	 */
	public static function save( WP_REST_Request $request ) {
		$p    = (array) $request->get_json_params();
		$id   = isset( $p['id'] ) ? (int) $p['id'] : 0;
		$user = $id ? get_userdata( $id ) : false;
		if ( ! $user || ! user_can( $user, 'edit_posts' ) ) {
			return new WP_Error( 'gralus_author', 'That user can\'t write posts on this site.', array( 'status' => 400 ) );
		}
		$update = array( 'ID' => $id );
		if ( array_key_exists( 'bio', $p ) ) {
			$update['description'] = wp_kses_post( wp_unslash( (string) $p['bio'] ) );
		}
		if ( array_key_exists( 'url', $p ) ) {
			$update['user_url'] = esc_url_raw( (string) $p['url'] );
		}
		if ( count( $update ) > 1 ) {
			$res = wp_update_user( $update );
			if ( is_wp_error( $res ) ) {
				return $res;
			}
		}
		if ( array_key_exists( 'jobTitle', $p ) ) {
			update_user_meta( $id, self::JOB_META, sanitize_text_field( (string) $p['jobTitle'] ) );
		}
		if ( array_key_exists( 'linkedin', $p ) ) {
			$link = esc_url_raw( (string) $p['linkedin'] );
			if ( '' !== $link && ! preg_match( '#^https://([a-z]{2,3}\.)?linkedin\.com/#i', $link ) ) {
				return new WP_Error( 'gralus_author', 'That isn\'t a LinkedIn address.', array( 'status' => 400 ) );
			}
			update_user_meta( $id, self::LINKEDIN_META, $link );
		}
		if ( array_key_exists( 'photoId', $p ) ) {
			$photo = (int) $p['photoId'];
			if ( $photo && ! wp_attachment_is_image( $photo ) ) {
				return new WP_Error( 'gralus_author', 'The photo isn\'t an image in the Media Library.', array( 'status' => 400 ) );
			}
			if ( $photo ) {
				update_user_meta( $id, self::PHOTO_META, $photo );
			} else {
				delete_user_meta( $id, self::PHOTO_META );
			}
		}
		update_option( self::OPTION, $id, false );
		return array( 'ok' => true, 'author' => self::describe( get_userdata( $id ) ) );
	}

	/** Show the photo chosen in Gralus wherever WordPress shows the user's avatar. */
	public static function avatar( $args, $id_or_email ) {
		$user_id = 0;
		if ( $id_or_email instanceof WP_User ) {
			$user_id = $id_or_email->ID;
		} elseif ( $id_or_email instanceof WP_Post ) {
			$user_id = (int) $id_or_email->post_author;
		} elseif ( $id_or_email instanceof WP_Comment ) {
			$user_id = (int) $id_or_email->user_id;
		} elseif ( is_numeric( $id_or_email ) ) {
			$user_id = (int) $id_or_email;
		}
		$photo = $user_id ? (int) get_user_meta( $user_id, self::PHOTO_META, true ) : 0;
		if ( $photo ) {
			$size = isset( $args['size'] ) ? (int) $args['size'] : 96;
			$src  = wp_get_attachment_image_src( $photo, array( $size, $size ) );
			if ( $src ) {
				$args['url']          = $src[0];
				$args['found_avatar'] = true;
			}
		}
		return $args;
	}

	/**
	 * On posts by the chosen author, when no SEO plugin describes the author already: Article markup naming the author
	 * as a Person (name, job title, bio, photo, website and LinkedIn).
	 */
	public static function print_schema() {
		if ( ! is_singular( 'post' ) || defined( 'WPSEO_VERSION' ) || class_exists( 'RankMath' ) ) {
			return;
		}
		$post = get_queried_object();
		if ( ! $post instanceof WP_Post || (int) $post->post_author !== (int) get_option( self::OPTION, 0 ) ) {
			return;
		}
		$u = get_userdata( (int) $post->post_author );
		if ( ! $u ) {
			return;
		}
		$person = array(
			'@type' => 'Person',
			'name'  => $u->display_name,
			'url'   => get_author_posts_url( $u->ID ),
		);
		$job  = (string) get_user_meta( $u->ID, self::JOB_META, true );
		$bio  = wp_strip_all_tags( (string) get_user_meta( $u->ID, 'description', true ) );
		$same = array_values( array_filter( array( (string) $u->user_url, (string) get_user_meta( $u->ID, self::LINKEDIN_META, true ) ) ) );
		if ( '' !== $job ) {
			$person['jobTitle'] = $job;
		}
		if ( '' !== $bio ) {
			$person['description'] = $bio;
		}
		if ( $same ) {
			$person['sameAs'] = $same;
		}
		$avatar = get_avatar_url( $u->ID, array( 'size' => 256 ) );
		if ( $avatar ) {
			$person['image'] = $avatar;
		}
		$data = array(
			'@context'         => 'https://schema.org',
			'@type'            => 'Article',
			'headline'         => wp_strip_all_tags( get_the_title( $post ) ),
			'datePublished'    => get_post_time( 'c', true, $post ),
			'dateModified'     => get_post_modified_time( 'c', true, $post ),
			'mainEntityOfPage' => get_permalink( $post ),
			'author'           => $person,
		);
		wp_print_inline_script_tag( wp_json_encode( $data, JSON_UNESCAPED_SLASHES | JSON_HEX_TAG ), array( 'type' => 'application/ld+json' ) );
	}
}