<?php
namespace DigiDiscount;

defined( 'ABSPATH' ) || exit;

final class Storage {
    public const POST_TYPE = 'digidiscount_rule';
    public const META_KEY = '_digidiscount_rule';
    private const VERSION = '1';

    public static function post_types(): array {
        return self::VERSION === get_option( 'digidiscount_storage_version' ) ? array( self::POST_TYPE ) : array( self::POST_TYPE, 'dd_campaign' );
    }

    private static function legacy_rule( int $id ): array {
        $rule = get_post_meta( $id, '_dd_rule', true );
        return is_array( $rule ) && isset( $rule['name'], $rule['type'], $rule['kind'], $rule['currency'] ) && isset( $rule['products'] ) && is_array( $rule['products'] ) ? $rule : array();
    }

    public static function is_campaign( int $id ): bool {
        $type = get_post_type( $id );
        return self::POST_TYPE === $type || ( 'dd_campaign' === $type && self::legacy_rule( $id ) );
    }

    public static function rule( int $id ): array {
        if ( ! self::is_campaign( $id ) ) {
            return array();
        }
        if ( metadata_exists( 'post', $id, self::META_KEY ) ) {
            $rule = get_post_meta( $id, self::META_KEY, true );
            return is_array( $rule ) ? $rule : array();
        }
        return self::legacy_rule( $id );
    }

    public static function migrate(): void {
        if ( self::VERSION === get_option( 'digidiscount_storage_version' ) ) {
            return;
        }
        $complete = true;
        $legacy_mode = get_option( 'dd_mode' );
        if ( false === get_option( 'digidiscount_mode' ) && in_array( $legacy_mode, array( 'best', 'priority', 'stack' ), true ) ) {
            add_option( 'digidiscount_mode', $legacy_mode, '', false );
            $complete = false !== get_option( 'digidiscount_mode' );
        }
        $ids = get_posts( array( 'post_type' => 'dd_campaign', 'post_status' => array_keys( get_post_stati() ), 'numberposts' => -1, 'fields' => 'ids' ) );
        foreach ( $ids as $id ) {
            $rule = self::legacy_rule( $id );
            if ( ! $rule ) {
                continue;
            }
            if ( ! metadata_exists( 'post', $id, self::META_KEY ) ) {
                update_post_meta( $id, self::META_KEY, wp_slash( $rule ) );
                if ( get_post_meta( $id, self::META_KEY, true ) !== $rule ) {
                    $complete = false;
                    continue;
                }
            }
            $result = wp_update_post( array( 'ID' => $id, 'post_type' => self::POST_TYPE ), true );
            if ( is_wp_error( $result ) || ! $result || self::POST_TYPE !== get_post_type( $id ) ) {
                $complete = false;
            }
        }
        if ( $complete ) {
            update_option( 'digidiscount_storage_version', self::VERSION, false );
        }
    }
}