<?php
/**
 * Per-post SEO fields: one definition used by the editor box, the REST API (Sites app) and the importer.
 * A blank field means "generate it automatically", so nothing ever has to be filled in.
 */

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

class SXSEO_Fields {

	const PREFIX = '_sxseo_';

	/** key => type */
	public static function defs() {
		return array(
			'title'           => 'text',
			'desc'            => 'textarea',
			'focus'           => 'text',
			'keywords'        => 'text',
			'noindex'         => 'bool',
			'nofollow'        => 'bool',
			'noarchive'       => 'bool',
			'nosnippet'       => 'bool',
			'noimageindex'    => 'bool',
			'canonical'       => 'url',
			'exclude_sitemap' => 'bool',
			'schema_type'     => 'text',
			'og_title'        => 'text',
			'og_desc'         => 'textarea',
			'og_image'        => 'url',
			'faq'             => 'faq',
		);
	}

	public static function hook() {
		foreach ( self::defs() as $key => $type ) {
			register_post_meta(
				'',
				self::PREFIX . $key,
				array(
					'show_in_rest'  => false,
					'single'        => true,
					'type'          => 'faq' === $type ? 'array' : 'string',
					'auth_callback' => function () {
						return current_user_can( 'edit_posts' );
					},
				)
			);
		}
		add_action( 'save_post', array( __CLASS__, 'touch_score' ), 20, 2 );
	}

	public static function get( $post_id, $key ) {
		$v = get_post_meta( $post_id, self::PREFIX . $key, true );
		if ( 'faq' === ( self::defs()[ $key ] ?? '' ) ) {
			return is_array( $v ) ? $v : array();
		}
		return is_string( $v ) ? $v : '';
	}

	public static function sanitize( $key, $value ) {
		$type = self::defs()[ $key ] ?? 'text';
		switch ( $type ) {
			case 'bool':
				return $value ? '1' : '';
			case 'url':
				return esc_url_raw( (string) $value );
			case 'textarea':
				return sanitize_textarea_field( (string) $value );
			case 'faq':
				$rows = array();
				foreach ( (array) $value as $r ) {
					$q = sanitize_text_field( $r['q'] ?? '' );
					$a = sanitize_textarea_field( $r['a'] ?? '' );
					if ( '' !== $q && '' !== $a ) {
						$rows[] = array( 'q' => $q, 'a' => $a );
					}
				}
				return array_slice( $rows, 0, 20 );
			default:
				return sanitize_text_field( (string) $value );
		}
	}

	/** Save any subset of fields. Empty value deletes the meta (= back to automatic). */
	public static function save( $post_id, array $values ) {
		foreach ( self::defs() as $key => $type ) {
			if ( ! array_key_exists( $key, $values ) ) {
				continue;
			}
			$v = self::sanitize( $key, $values[ $key ] );
			if ( '' === $v || array() === $v ) {
				delete_post_meta( $post_id, self::PREFIX . $key );
			} else {
				update_post_meta( $post_id, self::PREFIX . $key, $v );
			}
		}
		delete_post_meta( $post_id, '_sxseo_score' );
		SXSEO_Sitemap::purge();
	}

	public static function all_custom( $post_id ) {
		$out = array();
		foreach ( array_keys( self::defs() ) as $k ) {
			$out[ $k ] = self::get( $post_id, $k );
		}
		return $out;
	}

	/** Invalidate the cached score whenever the post changes. */
	public static function touch_score( $post_id, $post ) {
		if ( wp_is_post_revision( $post_id ) || wp_is_post_autosave( $post_id ) ) {
			return;
		}
		delete_post_meta( $post_id, '_sxseo_score' );
	}
}