<?php
/**
 * Whether a field should be overwritten on re-import.
 *
 * @package Kordiam
 */

declare( strict_types=1 );

namespace Kordiam\Import;

use Kordiam\Support\MetaKeys;
use Kordiam\Support\Options;

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

/**
 * Decides whether Kordiam may keep overwriting a field after the first import.
 */
final class FieldSyncPolicy {

	/**
	 * Option switching the status to initial-only syncing.
	 *
	 * @var string
	 */
	public const STATUS_OPTION = 'initial_status_syncing';

	/**
	 * Option switching the slug to initial-only syncing.
	 *
	 * @var string
	 */
	public const SLUG_OPTION = 'initial_slug_syncing';

	/**
	 * Blocking instantiation: this class is a namespaced function group.
	 */
	private function __construct() {
	}

	/**
	 * Checking whether the status may be taken from Kordiam.
	 *
	 * @param int $post_id Post ID, or 0 on a create.
	 *
	 * @return bool Whether the status should be synced.
	 */
	public static function may_sync_status( int $post_id ): bool {
		return self::may_sync( $post_id, self::STATUS_OPTION );
	}

	/**
	 * Checking whether the slug may be taken from Kordiam.
	 *
	 * @param int $post_id Post ID, or 0 on a create.
	 *
	 * @return bool Whether the slug should be synced.
	 */
	public static function may_sync_slug( int $post_id ): bool {
		return self::may_sync( $post_id, self::SLUG_OPTION );
	}

	/**
	 * Deciding whether a field may be synced onto a post.
	 *
	 * The first import (no story link yet) always proceeds regardless of the setting.
	 *
	 * @param int    $post_id    Post ID, or 0 on a create.
	 * @param string $option_key Option switching this field to initial-only syncing.
	 *
	 * @return bool Whether the field should be synced.
	 */
	private static function may_sync( int $post_id, string $option_key ): bool {
		if ( $post_id <= 0 ) {
			return true;
		}

		if ( ! Options::get_bool( $option_key ) ) {
			return true;
		}

		return ! self::is_linked_to_a_story( $post_id );
	}

	/**
	 * Checking whether a post is already linked to a Kordiam story.
	 *
	 * @param int $post_id Post ID.
	 *
	 * @return bool Whether a story ID is recorded against the post.
	 */
	public static function is_linked_to_a_story( int $post_id ): bool {
		if ( $post_id <= 0 ) {
			return false;
		}

		$story_id = get_post_meta( $post_id, MetaKeys::STORY_ID, true );

		if ( is_numeric( $story_id ) && (int) $story_id > 0 ) {
			return true;
		}

		$legacy = get_post_meta( $post_id, MetaKeys::legacy_post_meta()[ MetaKeys::STORY_ID ], true );

		return is_numeric( $legacy ) && (int) $legacy > 0;
	}
}