<?php
/**
 * Plugin Name: EKSRelay API
 * Description: Dedykowane REST API dla EKSRelay – get_car_data i get_product_compatibility.
 *              Otwarte endpointy REST (bez autoryzacji) – odpowiedniki nopriv AJAX.
 *              Wdróż ten plik na serwer WP jako: /wp-content/mu-plugins/eksrelay_api.php
 * Version:     1.0.0
 */

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

// ═══════════════════════════════════════════════════════════════════
// Rejestracja tras REST
// ═══════════════════════════════════════════════════════════════════

add_action( 'rest_api_init', function () {
    register_rest_route( 'eksrelay/v1', '/car-data', [
        'methods'             => 'POST',
        'callback'            => 'eksrelay_car_data',
        'permission_callback' => '__return_true',
    ] );

    register_rest_route( 'eksrelay/v1', '/product-compatibility', [
        'methods'             => 'POST',
        'callback'            => 'eksrelay_product_compatibility',
        'permission_callback' => '__return_true',
    ] );
} );

// ═══════════════════════════════════════════════════════════════════
// Handler: POST /wp-json/eksrelay/v1/car-data
//
// Body JSON: { car_year, car_brand?, car_model?, car_engine? }
// ═══════════════════════════════════════════════════════════════════

function eksrelay_car_data( WP_REST_Request $request ) {
    $body = $request->get_json_params() ?: [];

    if ( empty( $body['car_year'] ) ) {
        return [ 'error' => 'car_year jest wymagany' ];
    }

    $car_year  = intval( sanitize_text_field( $body['car_year'] ) );
    $has_brand = ! empty( $body['car_brand'] );
    $has_model = ! empty( $body['car_model'] );
    $car_brand = false;
    $car_model = false;

    if ( ! $has_brand && ! $has_model ) {
        return [ 'error' => 'car_brand lub car_model jest wymagany' ];
    }

    // ── Tylko brand, bez modelu ──────────────────────────────────────
    if ( $has_brand && ! $has_model ) {
        $car_brand = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_brand'] ) ) );
        $termIds   = get_terms( [ 'name__like' => $car_brand, 'parent' => 0, 'fields' => 'ids' ] );

        if ( count( $termIds ) === 1 ) {
            $car_models = eksrelay_models_for_brand_year( $termIds, $car_year );
            return [ 'error' => 'options', 'field' => 'car_model', 'options' => $car_models, 'filtered' => false ];
        }

        return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
    }

    // ── Tylko model, bez brandu ─────────────────────────────────────
    if ( $has_model && ! $has_brand ) {
        $car_model = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_model'] ) ) );
        $termIds   = get_terms( [ 'name__like' => $car_model, 'fields' => 'ids' ] );

        // exact match → auto-wybierz
        foreach ( $termIds as $tid ) {
            $term = get_term_by( 'id', $tid, 'car_model' );
            if ( $term && eksrelay_replace_ascii( $term->name ) === $car_model ) {
                $termIds = [ $term->term_id ];
                break;
            }
        }

        if ( count( $termIds ) === 1 ) {
            $term = get_term( $termIds[0] );
            if ( ! is_wp_error( $term ) && $term->parent !== 0 ) {
                $parent = get_term( $term->parent );
                if ( ! is_wp_error( $parent ) ) {
                    $car_brand = $parent->name;
                }
            } else {
                return [ 'error' => 'nie znaleziono takiego modelu', 'car_model' => $car_model ];
            }
        } else {
            $models = [];
            foreach ( $termIds as $tid ) {
                $t = get_term_by( 'id', $tid, 'car_model' );
                if ( $t ) {
                    $models[] = $t->name;
                }
            }
            if ( $models ) {
                return [ 'error' => 'options', 'field' => 'car_model', 'options' => $models, 'filtered' => true ];
            }
            return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
        }
    }

    // ── Mamy oba ────────────────────────────────────────────────────
    if ( ! $car_brand ) {
        $car_brand = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_brand'] ) ) );
    }
    if ( ! $car_model ) {
        $car_model = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_model'] ) ) );
    }
    $car_engine = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_engine'] ?? '' ) ) );

    $termIds  = get_terms( [ 'name__like' => $car_brand, 'fields' => 'ids' ] );
    $termIds2 = get_terms( [ 'name__like' => $car_model, 'fields' => 'ids' ] );

    if ( ! count( $termIds ) ) {
        return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
    }

    if ( ! count( $termIds2 ) ) {
        if ( count( $termIds ) === 1 ) {
            $car_models = eksrelay_models_for_brand_year( $termIds, $car_year );
            return [ 'error' => 'options', 'field' => 'car_model', 'options' => $car_models, 'filtered' => false ];
        }
        return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
    }

    $query = new WP_Query( [
        'post_type'      => 'car',
        'posts_per_page' => -1,
        'tax_query'      => [
            'relation' => 'AND',
            [ 'taxonomy' => 'car_model',           'field' => 'id',   'terms' => $termIds ],
            [ 'taxonomy' => 'car_model',           'field' => 'id',   'terms' => $termIds2 ],
            [ 'taxonomy' => 'car_production_year', 'field' => 'slug', 'terms' => (string) $car_year ],
        ],
    ] );

    $cars        = $query->get_posts();
    $engine_info = eksrelay_get_engines_info( $cars, true, $car_year );

    if ( ! $cars ) {
        return [
            'error'     => 'nie znaleziono auta, ' . get_option(
                'aiac_tool_get_car_data_no_car',
                'Orientacyjnie do 1994 roku włącznie powinien pasować gaz R12, dla aut 1995-2016 gaz R134A a dla aut od 2016 roku gaz R1234YF'
            ),
            'car_brand' => $car_brand,
            'car_model' => $car_model,
        ];
    }

    $engine_names = array_column( $engine_info, 'name' );

    if ( count( $engine_info ) === 1 ) {
        $car_engine = $engine_info[0]['name'];
    }

    if ( count( $engine_info ) > 1 && ! $car_engine ) {
        return [ 'error' => 'options', 'field' => 'car_engine', 'options' => $engine_names, 'filtered' => false ];
    }

    foreach ( $engine_info as $eng ) {
        if ( strtolower( trim( $eng['name'] ) ) !== strtolower( trim( $car_engine ) ) ) {
            continue;
        }

        $car_id     = intval( $eng['id'] );
        $maybe_diff = get_field( 'custom_ac', $car_id );

        $gas_types = array_unique( array_filter( [
            get_field( 'ac_gas_type', $car_id ),
            $maybe_diff ? get_field( 'ac_gas_type_2', $car_id ) : '',
        ] ) );

        $year_term  = get_terms( [ 'taxonomy' => 'car_production_year', 'name__like' => $car_year ] );
        $brand_term = $termIds  ? get_term( $termIds[0] )  : false;
        $model_term = $termIds2 ? get_term( $termIds2[0] ) : false;

        $data = [
            'success'      => true,
            'selected_car' => [
                'ek_ac_gas_type' => implode( ',', $gas_types ),
                'ek_brand_id'    => $termIds[0]  ?? '',
                'ek_brand'       => ( $brand_term && ! is_wp_error( $brand_term ) ) ? $brand_term->name : $car_brand,
                'ek_car_id'      => $car_id,
                'ek_engine_type' => $eng['name'],
                'ek_info'        => '',
                'ek_model_id'    => $termIds2[0] ?? '',
                'ek_model'       => ( $model_term && ! is_wp_error( $model_term ) ) ? $model_term->name : $car_model,
                'ek_year_id'     => ( ! is_wp_error( $year_term ) && $year_term ) ? $year_term[0]->term_id : '',
                'ek_year'        => $car_year,
            ],
            'shop_url'               => $eng['url'],
            'adapters'               => get_field( 'adapters', $car_id ) ?: false,
            'ac_gas_type'            => get_field( 'ac_gas_type', $car_id ),
            'ac_gas_amount'          => ( get_field( 'ac_gas_amount', $car_id ) ?: '-' ) . ' g',
            'ac_ports_count'         => intval( get_field( 'ac_ports_count', $car_id ) ),
            'ac_oil'                 => get_field( 'ac_oil', $car_id ),
            'ac_oil_amount'          => ( get_field( 'ac_oil_amount', $car_id ) ?: '-' ) . ' cm3',
            'ac_clutch'              => get_field( 'ac_clutch', $car_id ),
            'maybe_different_layout' => $maybe_diff,
        ];

        if ( $maybe_diff ) {
            $data['different_layout_info']            = get_field( 'custom_ac_info', $car_id ) ?: '';
            $data['different_layout_adapters']        = get_field( 'adapters_2', $car_id ) ?: false;
            $data['different_layout_ac_gas_type']     = get_field( 'ac_gas_type_2', $car_id );
            $data['different_layout_ac_gas_amount']   = ( get_field( 'ac_gas_amount_2', $car_id ) ?: '-' ) . ' g';
            $data['different_layout_ac_ports_count']  = get_field( 'ac_ports_count_2', $car_id );
            $data['different_layout_ac_oil']          = get_field( 'ac_oil_2', $car_id );
            $data['different_layout_ac_oil_amount']   = ( get_field( 'ac_oil_amount_2', $car_id ) ?: '-' ) . ' cm3';
            $data['different_layout_ac_clutch']       = get_field( 'ac_clutch_2', $car_id );
        }

        return $data;
    }

    // podany silnik nie pasuje do żadnego na liście → pokaż opcje
    return [ 'error' => 'options', 'field' => 'car_engine', 'options' => $engine_names, 'filtered' => false ];
}

// ═══════════════════════════════════════════════════════════════════
// Handler: POST /wp-json/eksrelay/v1/product-compatibility
//
// Body JSON: { car_year, car_brand?, car_model?, car_engine?, product_name? }
// ═══════════════════════════════════════════════════════════════════

function eksrelay_product_compatibility( WP_REST_Request $request ) {
    $body = $request->get_json_params() ?: [];

    if ( empty( $body['car_year'] ) ) {
        return [ 'error' => 'car_year jest wymagany' ];
    }

    $lang      = sanitize_text_field( $body['lang'] ?? 'pl' );
    $car_year  = intval( sanitize_text_field( $body['car_year'] ) );
    $has_brand = ! empty( $body['car_brand'] );
    $has_model = ! empty( $body['car_model'] );
    $car_brand = false;
    $car_model = false;

    // ── Tylko brand ─────────────────────────────────────────────────
    if ( $has_brand && ! $has_model ) {
        $car_brand = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_brand'] ) ) );
        $termIds   = get_terms( [ 'name__like' => $car_brand, 'parent' => 0, 'fields' => 'ids' ] );

        if ( count( $termIds ) === 1 ) {
            $car_models = eksrelay_models_for_brand_year( $termIds, $car_year );
            return [ 'error' => 'options', 'field' => 'car_model', 'options' => $car_models, 'filtered' => false ];
        }

        return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
    }

    // ── Tylko model ─────────────────────────────────────────────────
    if ( $has_model && ! $has_brand ) {
        $car_model = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_model'] ) ) );
        $termIds   = get_terms( [ 'name__like' => $car_model, 'fields' => 'ids' ] );

        if ( count( $termIds ) === 1 ) {
            $term = get_term( $termIds[0] );
            if ( ! is_wp_error( $term ) && $term->parent !== 0 ) {
                $parent = get_term( $term->parent );
                if ( ! is_wp_error( $parent ) ) {
                    $car_brand = $parent->name;
                }
            } else {
                return [ 'error' => 'nie znaleziono takiego modelu', 'car_model' => $car_model ];
            }
        } else {
            $models = [];
            foreach ( $termIds as $tid ) {
                $t = get_term_by( 'id', $tid, 'car_model' );
                if ( $t ) {
                    $models[] = $t->name;
                }
            }
            if ( $models ) {
                return [ 'error' => 'options', 'field' => 'car_model', 'options' => $models, 'filtered' => true ];
            }
            return [ 'error' => 'options', 'field' => 'car_brand', 'options' => eksrelay_all_brands(), 'filtered' => false ];
        }
    }

    if ( ! $has_brand && ! $has_model ) {
        return [ 'error' => 'car_brand lub car_model jest wymagany' ];
    }

    if ( ! $car_brand ) {
        $car_brand = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_brand'] ) ) );
    }
    if ( ! $car_model ) {
        $car_model = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_model'] ) ) );
    }

    $car_engine   = eksrelay_replace_ascii( trim( sanitize_text_field( $body['car_engine']   ?? '' ) ) );
    $product_name = eksrelay_replace_ascii( trim( sanitize_text_field( $body['product_name'] ?? '' ) ) );

    // ── Znajdź produkt ──────────────────────────────────────────────
    $product = false;

    if ( $product_name ) {
        $products = eksrelay_search_products_by_name( $product_name );

        if ( count( $products ) > 1 ) {
            // exact match → auto-wybierz
            foreach ( $products as $p ) {
                if ( eksrelay_replace_ascii( strtolower( trim( $p->get_title() ) ) ) === strtolower( $product_name ) ) {
                    $product = $p;
                    break;
                }
            }
            if ( ! $product ) {
                return [
                    'error'    => 'options',
                    'field'    => 'product_name',
                    'options'  => array_map( fn( $p ) => $p->get_title(), $products ),
                    'filtered' => true,
                ];
            }
        } elseif ( count( $products ) === 1 ) {
            $product = $products[0];
        }
    }

    // ── Znajdź auto ─────────────────────────────────────────────────
    $termIds  = get_terms( [ 'name__like' => $car_brand, 'fields' => 'ids' ] );
    $termIds2 = get_terms( [ 'name__like' => $car_model, 'fields' => 'ids' ] );

    // Uwaga: celowo bez filtra roku – engine_info filtruje rok wewnętrznie
    $query = new WP_Query( [
        'post_type'      => 'car',
        'posts_per_page' => -1,
        'tax_query'      => [
            'relation' => 'AND',
            [ 'taxonomy' => 'car_model', 'field' => 'id', 'terms' => $termIds ],
            [ 'taxonomy' => 'car_model', 'field' => 'id', 'terms' => $termIds2 ],
        ],
    ] );

    $cars        = $query->get_posts();
    $engine_info = eksrelay_get_engines_info( $cars, false, $car_year );

    if ( ! $cars ) {
        return [ 'error' => 'nie znaleziono takiego samochodu', 'car_brand' => $car_brand, 'car_model' => $car_model ];
    }

    $engine_names = array_column( $engine_info, 'name' );

    if ( count( $engine_info ) === 1 ) {
        $car_engine = $engine_info[0]['name'];
    }

    if ( count( $engine_info ) > 1 && ! $car_engine ) {
        return [ 'error' => 'options', 'field' => 'car_engine', 'options' => $engine_names, 'filtered' => false ];
    }

    foreach ( $engine_info as $eng ) {
        if ( strtolower( trim( $eng['name'] ) ) !== strtolower( trim( $car_engine ) ) ) {
            continue;
        }

        $engine_gas      = array_values( array_filter( [ $eng['ac_gas_type'] ?? '', $eng['ac_gas_type_2'] ?? '' ] ) );
        $engine_adapters = array_values( array_filter( [ $eng['adapters'] ?? '', $eng['adapters_2'] ?? '' ] ) );
        if ( ! $engine_gas )      $engine_gas      = [ 'no-gas' ];
        if ( ! $engine_adapters ) $engine_adapters = [ 'no' ];

        if ( $product ) {
            // ── Sprawdzenie kompatybilności konkretnego produktu ─────────
            $attributes = eksrelay_product_attributes( $product );
            foreach ( $attributes as $k => $arr ) {
                $attributes[ $k ] = array_map( fn( $slug ) => str_replace( "-{$lang}", '', $slug ), $arr );
            }

            if ( ! isset( $attributes['pa_rg'] ) || empty( $attributes['pa_rg'] ) ) $attributes['pa_rg'] = [ 'no-gas' ];
            if ( ! isset( $attributes['pa_ra'] ) || empty( $attributes['pa_ra'] ) ) $attributes['pa_ra'] = [ 'no' ];

            $gas_fit     = count( array_intersect( $engine_gas,      $attributes['pa_rg'] ) ) > 0;
            $adapter_fit = count( array_intersect( $engine_adapters, $attributes['pa_ra'] ) ) > 0;

            return [
                'success'          => true,
                'fit'              => $gas_fit && $adapter_fit,
                'gas_fit'          => $gas_fit,
                'adapter_fit'      => $adapter_fit,
                'selected_engine'  => $eng,
                'selected_product' => [
                    'id'         => $product->get_id(),
                    'title'      => $product->get_title(),
                    'type'       => $product->get_type(),
                    'attributes' => $attributes,
                ],
            ];
        }

        // ── Brak konkretnego produktu – lista wszystkich kompatybilnych ─
        $all_products = wc_get_products( [
            'status'     => 'publish',
            'visibility' => 'visible',
            'limit'      => -1,
            'orderby'    => 'name',
        ] );

        $compatible = [];
        foreach ( $all_products as $p ) {
            $attrs = eksrelay_product_attributes( $p );
            foreach ( $attrs as $k => $arr ) {
                $attrs[ $k ] = array_map( fn( $slug ) => str_replace( "-{$lang}", '', $slug ), $arr );
            }
            $p_gas      = ( isset( $attrs['pa_rg'] ) && ! empty( $attrs['pa_rg'] ) ) ? $attrs['pa_rg'] : [ 'no-gas' ];
            $p_adapters = ( isset( $attrs['pa_ra'] ) && ! empty( $attrs['pa_ra'] ) ) ? $attrs['pa_ra'] : [ 'no' ];

            if (
                count( array_intersect( $engine_gas,      $p_gas      ) ) > 0 &&
                count( array_intersect( $engine_adapters, $p_adapters ) ) > 0
            ) {
                $compatible[] = [
                    'id'        => $p->get_id(),
                    'title'     => $p->get_title(),
                    'price'     => $p->get_price(),
                    'permalink' => get_permalink( $p->get_id() ),
                ];
            }
        }

        return [
            'success'             => true,
            'compatible_products' => $compatible,
            'selected_engine'     => $eng,
        ];
    }

    return [ 'error' => 'options', 'field' => 'car_engine', 'options' => $engine_names, 'filtered' => false ];
}

// ═══════════════════════════════════════════════════════════════════
// Pomocnicze funkcje wewnętrzne
// ═══════════════════════════════════════════════════════════════════

/**
 * Zwraca listę modeli dla danej marki (termIds) i roku produkcji.
 */
function eksrelay_models_for_brand_year( array $termIds, int $car_year ): array {
    $query = new WP_Query( [
        'post_type'      => 'car',
        'posts_per_page' => -1,
        'tax_query'      => [
            'relation' => 'AND',
            [ 'taxonomy' => 'car_model',           'field' => 'id',   'terms' => $termIds ],
            [ 'taxonomy' => 'car_production_year', 'field' => 'slug', 'terms' => [ (string) $car_year ] ],
        ],
    ] );

    $car_models = [];
    foreach ( $query->get_posts() as $car ) {
        foreach ( wp_get_post_terms( $car->ID, 'car_model' ) as $term ) {
            if ( ! in_array( $term->name, $car_models, true ) && $term->parent !== 0 ) {
                $car_models[] = $term->name;
            }
        }
    }

    return $car_models;
}

/**
 * Zwraca listę wszystkich marek aut (terminy car_model z parent=0).
 */
function eksrelay_all_brands(): array {
    return (array) get_terms( [
        'taxonomy'   => 'car_model',
        'parent'     => 0,
        'fields'     => 'names',
        'hide_empty' => true,
    ] );
}

/**
 * Zwraca info o silnikach dla podanych postów 'car'.
 *
 * Parametr $prefiltered:
 *   true  – WP_Query już przefiltrował po roku przez taxonomy (get_car_data)
 *   false – rok musi być sprawdzony wewnętrznie przez pola ACF year_from / year_to (get_product_compatibility)
 *
 * Nazwa silnika jest budowana z pól ACF: engine_type, engine_size (ccm), engine_power_kw, engine_power_km.
 * Format: "B 1.8 - 141 kW / 192 KM"
 *
 * Zakres roku pochodzi z pól ACF year_from / year_to (przechowywane jako term_id taksonomii car_production_year).
 *
 * Dodatkowe warianty silnika mogą być przechowywane w ACF repeaterze 'engines' na poście car.
 */
function eksrelay_get_engines_info( array $cars, bool $prefiltered, int $car_year ): array {
    $engines = [];
    $seen    = [];

    foreach ( $cars as $car ) {
        $car_id = $car->ID;

        // ── Filtrowanie zakresu roku przez pola ACF year_from / year_to ─
        if ( $car_year ) {
            $year_from_id = get_field( 'year_from', $car_id );
            $year_to_id   = get_field( 'year_to',   $car_id );

            $year_from = 0;
            $year_to   = 9999;

            if ( $year_from_id ) {
                $t = get_term( (int) $year_from_id, 'car_production_year' );
                if ( $t && ! is_wp_error( $t ) ) {
                    $year_from = (int) $t->slug;
                }
            }
            if ( $year_to_id ) {
                $t = get_term( (int) $year_to_id, 'car_production_year' );
                if ( $t && ! is_wp_error( $t ) ) {
                    $year_to = (int) $t->slug;
                }
            }

            if ( $car_year < $year_from || $car_year > $year_to ) {
                continue;
            }
        }

        // ── Budowanie nazwy silnika z pól ACF ────────────────────────────
        $engine_type    = (string) ( get_field( 'engine_type',     $car_id ) ?: '' );
        $engine_size_cc = (float)  ( get_field( 'engine_size',     $car_id ) ?: 0 );
        $power_kw       = (string) ( get_field( 'engine_power_kw', $car_id ) ?: '' );
        $power_km       = (string) ( get_field( 'engine_power_km', $car_id ) ?: '' );
        $engine_size    = number_format( $engine_size_cc / 1000, 1 );
        $name           = "{$engine_type} {$engine_size} - {$power_kw} kW / {$power_km} KM";

        // ── Typ gazu i adaptery ──────────────────────────────────────────
        $ac_gas_type   = (string) ( get_field( 'ac_gas_type',   $car_id ) ?: '' );
        $ac_gas_type_2 = (string) ( get_field( 'ac_gas_type_2', $car_id ) ?: '' );
        $adapters_raw  = get_field( 'adapters',   $car_id );
        $adapters_raw2 = get_field( 'adapters_2', $car_id );
        $adapters      = is_array( $adapters_raw  ) ? ( implode( ',', $adapters_raw  ) ?: 'no' ) : (string) ( $adapters_raw  ?: 'no' );
        $adapters_2    = is_array( $adapters_raw2 ) ? implode( ',', $adapters_raw2 ) : (string) ( $adapters_raw2 ?: '' );

        // ── Korekty gazu na podstawie roku (sanity check) ────────────────
        if ( $car_year ) {
            if ( $car_year <= 1994 && $ac_gas_type === '' ) {
                $ac_gas_type = 'r12';
            } elseif ( $car_year >= 2017 && $ac_gas_type === '' ) {
                $ac_gas_type = 'r1234yf';
            } elseif ( $car_year >= 1995 && $car_year <= 2016 && $ac_gas_type === '' ) {
                $ac_gas_type = 'r134a';
            }
        }

        // ── Główny silnik ────────────────────────────────────────────────
        $key = mb_strtolower( $name );
        if ( ! isset( $seen[ $key ] ) ) {
            $seen[ $key ] = true;
            $engines[] = [
                'name'          => $name,
                'id'            => $car_id,
                'url'           => get_permalink( $car_id ),
                'ac_gas_type'   => $ac_gas_type,
                'ac_gas_type_2' => $ac_gas_type_2,
                'adapters'      => $adapters,
                'adapters_2'    => $adapters_2,
            ];
        }

        // ── ACF repeater 'engines' – dodatkowe warianty silnika ──────────
        $extra_engines = get_field( 'engines', $car_id );
        if ( is_array( $extra_engines ) ) {
            foreach ( $extra_engines as $extra ) {
                $e_type    = (string) ( $extra['engine_type']     ?? '' );
                $e_size_cc = (float)  ( $extra['engine_size']     ?? 0 );
                $e_kw      = (string) ( $extra['engine_power_kw'] ?? '' );
                $e_km      = (string) ( $extra['engine_power_km'] ?? '' );
                $e_size    = number_format( $e_size_cc / 1000, 1 );
                $e_name    = "{$e_type} {$e_size} - {$e_kw} kW / {$e_km} KM";

                $e_gas     = (string) ( $extra['ac_gas_type']   ?? $ac_gas_type );
                $e_gas_2   = (string) ( $extra['ac_gas_type_2'] ?? $ac_gas_type_2 );
                $e_adp_r   = $extra['adapters']   ?? null;
                $e_adp_r2  = $extra['adapters_2'] ?? null;
                $e_adp     = is_array( $e_adp_r  ) ? implode( ',', $e_adp_r  ) : (string) ( $e_adp_r  ?: $adapters );
                $e_adp_2   = is_array( $e_adp_r2 ) ? implode( ',', $e_adp_r2 ) : (string) ( $e_adp_r2 ?: $adapters_2 );

                $e_key = mb_strtolower( $e_name );
                if ( ! isset( $seen[ $e_key ] ) ) {
                    $seen[ $e_key ] = true;
                    $engines[] = [
                        'name'          => $e_name,
                        'id'            => $car_id,
                        'url'           => get_permalink( $car_id ),
                        'ac_gas_type'   => $e_gas,
                        'ac_gas_type_2' => $e_gas_2,
                        'adapters'      => $e_adp,
                        'adapters_2'    => $e_adp_2,
                    ];
                }
            }
        }
    }

    return $engines;
}

/**
 * Zwraca atrybuty produktu WC jako [ slug_atrybutu => [ slug_wartości, ... ] ].
 * Używane do sprawdzania pa_rg (typ gazu) i pa_ra (adapter).
 *
 * Implementacja wzorowana na aiac_get_product_attributes_as_str_arr() z aiac_chat_api.php:
 * – dla wariantów (variation): [ $attr_val ] (pojedyncza wartość ze zmiennej produktowej)
 * – dla pozostałych typów: $attr_obj->get_slugs()
 */
function eksrelay_product_attributes( WC_Product $product ): array {
    $result     = [];
    $attributes = $product->get_attributes();

    if ( $product->is_type( 'variation' ) ) {
        foreach ( $attributes as $attr_key => $attr_val ) {
            $result[ $attr_key ] = [ $attr_val ];
        }
    } else {
        foreach ( $attributes as $attr_key => $attr_obj ) {
            $result[ $attr_key ] = $attr_obj->get_slugs();
        }
    }

    return $result;
}

/**
 * Wyszukuje produkty WooCommerce po fragmencie nazwy (fulltext search).
 */
function eksrelay_search_products_by_name( string $product_name ): array {
    add_filter( 'woocommerce_product_data_store_cpt_get_products_query', 'eksrelay_wc_query_like', 10, 2 );

    $products = wc_get_products( [
        'status' => 'publish',
        'limit'  => -1,
        'like'   => $product_name,
    ] );

    remove_filter( 'woocommerce_product_data_store_cpt_get_products_query', 'eksrelay_wc_query_like', 10 );

    return $products;
}

function eksrelay_wc_query_like( array $query, array $query_vars ): array {
    if ( ! empty( $query_vars['like'] ) ) {
        $query['s'] = esc_attr( $query_vars['like'] );
    }
    return $query;
}

/**
 * Usuwa znaki diakrytyczne z ciągu znaków.
 * Mapowanie identyczne z replace_ascii() w aiac_chat_api.php.
 */
function eksrelay_replace_ascii( string $string ): string {
    $map = [
        'Š' => 'S', 'š' => 's', 'ë' => 'e', 'Ë' => 'E',
        'ä' => 'a', 'Ä' => 'A', 'ö' => 'o', 'Ö' => 'O',
        'ü' => 'u', 'Ü' => 'U', 'ß' => 'ss',
        'ó' => 'o', 'Ó' => 'O', 'ł' => 'l', 'Ł' => 'L',
        'ń' => 'n', 'Ń' => 'N', 'ć' => 'c', 'Ć' => 'C',
        'ę' => 'e', 'Ę' => 'E', 'ź' => 'z', 'Ź' => 'Z',
        'ż' => 'z', 'Ż' => 'Z', 'á' => 'a', 'Á' => 'A',
        'č' => 'c', 'Č' => 'C', 'ď' => 'd', 'Ď' => 'D',
        'é' => 'e', 'É' => 'E', 'ě' => 'e', 'Ě' => 'E',
        'í' => 'i', 'Í' => 'I', 'ň' => 'n', 'Ň' => 'N',
        'ř' => 'r', 'Ř' => 'R', 'ś' => 's', 'Ś' => 'S',
        'ť' => 't', 'Ť' => 'T', 'ů' => 'u', 'Ů' => 'U',
        'ý' => 'y', 'Ý' => 'Y', 'ą' => 'a', 'Ą' => 'A',
        'ș' => 's', 'Ș' => 'S', 'î' => 'i', 'Î' => 'I',
        'â' => 'a', 'Â' => 'A', 'ț' => 't', 'Ț' => 'T',
        'ğ' => 'g', 'Ğ' => 'G', 'İ' => 'I', 'ı' => 'i',
        'ç' => 'c', 'Ç' => 'C',
    ];

    return str_replace( array_keys( $map ), array_values( $map ), $string );
}