<?php

declare(strict_types=1);
namespace FacetCore\WordPress;

/** Native post/meta persistence. Attribute IDs survive WooCommerce slug/label renames. */
final class TableConfiguration
{
    public const TYPE = 'facetcore_table';
    public const META = '_facetcore_configuration';

    public static function attributes(): array
    {
        $out = [];
        foreach (wc_get_attribute_taxonomies() as $attribute) {
            $id = (int) $attribute->attribute_id;
            $out['attribute:' . $id] = ['id' => $id, 'taxonomy' => wc_attribute_taxonomy_name($attribute->attribute_name), 'label' => $attribute->attribute_label];
        }
        return $out;
    }

    public static function fields(): array
    {
        return ['sku' => __('SKU', 'facetcore'), 'image' => __('Image', 'facetcore'), 'name' => __('Product', 'facetcore'), 'price' => __('Price', 'facetcore'), 'stock' => __('Availability', 'facetcore'), 'cart' => __('Add to cart', 'facetcore')];
    }

    public static function defaults(): array
    {
        return ['version' => 2, 'source' => 'all', 'categories' => [], 'enable_search' => true, 'views' => ['grid'], 'default_view' => 'grid', 'allow_switch' => false, 'grid_sku' => false, 'grid_attributes' => [], 'filters' => [], 'columns' => [], 'per_page' => 25, 'show_counts' => true, 'hide_impossible' => true, 'custom_css' => ''];
    }

    public static function sanitize(array $raw): array
    {
        $out = self::defaults();
        foreach (['filters'] as $kind) {
            $out[$kind] = [];
            foreach (is_array($raw[$kind] ?? null) ? $raw[$kind] : [] as $key) {
                if (!is_string($key)) { continue; }
                if (preg_match('/^attribute:[1-9][0-9]*$/D', $key)) {
                    $out[$kind][] = $key;
                }
            }
            $out[$kind] = array_values(array_unique($out[$kind]));
        }
        // The existing engine supports ten simultaneous facets.
        $out['filters'] = array_slice($out['filters'], 0, 10);
        $out['per_page'] = max(1, min(100, is_scalar($raw['per_page'] ?? null) ? (int) $raw['per_page'] : 25));
        foreach (['show_counts', 'hide_impossible'] as $key) { $out[$key] = in_array($raw[$key] ?? false, [true, 1, '1'], true); }
        $out['source'] = ($raw['source'] ?? 'all') === 'categories' ? 'categories' : 'all';
        $out['categories'] = array_values(array_unique(array_filter(array_map(static fn ($id) => is_scalar($id) && preg_match('/^[1-9][0-9]*$/D', (string) $id) ? (int) $id : 0, is_array($raw['categories'] ?? null) ? $raw['categories'] : []))));
        $out['categories'] = array_slice($out['categories'], 0, 100);
        $out['grid_sku'] = in_array($raw['grid_sku'] ?? false, [true, 1, '1'], true);
        $out['enable_search'] = in_array($raw['enable_search'] ?? true, [true, 1, '1'], true);
        // Opaque stored extension values survive Lite saves, but are never used without validation.
        foreach (self::extensionKeys() as $key) { if (array_key_exists($key, $raw)) { $out[$key] = $raw[$key]; } }
        return apply_filters('facetcore_sanitize_configuration', $out, $raw);
    }

    public static function extensionKeys(): array
    {
        return array_keys(self::extensionFeatures());
    }

    private static function extensionFeatures(): array
    {
        return ['views' => 'table', 'default_view' => 'table', 'allow_switch' => 'view_switch', 'columns' => 'table', 'grid_attributes' => 'card_attributes', 'custom_css' => 'custom_css'];
    }

    public static function effective(array $stored): array
    {
        $config = self::sanitize($stored);
        foreach (self::extensionKeys() as $key) { $config[$key] = self::defaults()[$key]; }
        $config = apply_filters('facetcore_effective_configuration', $config, $stored);
        foreach (self::extensionFeatures() as $key => $feature) { if (!Features::has($feature)) { $config[$key] = self::defaults()[$key]; } }
        return $config;
    }

    public static function forSave(array $raw, array $old): array
    {
        foreach (self::extensionFeatures() as $key => $feature) {
            if (Features::has($feature)) { continue; }
            unset($raw[$key]);
            if (array_key_exists($key, $old)) { $raw[$key] = $old[$key]; }
        }
        return self::sanitize($raw);
    }

    public static function get(int $id, bool $publishedOnly = true): ?array
    {
        if ($id < 1) { return null; }
        $post = get_post($id);
        if (!$post || $post->post_type !== self::TYPE || ($publishedOnly && ($post->post_status !== 'publish' || $post->post_password !== ''))) { return null; }
        $raw = get_post_meta($id, self::META, true);
        $config = is_array($raw) ? self::sanitize($raw) : self::defaults();
        return $publishedOnly ? self::effective($config) : $config;
    }

    public static function missing(array $config): array
    {
        $attrs = self::attributes();
        return array_values(array_filter(array_unique(array_merge($config['filters'], is_array($config['columns']) ? $config['columns'] : [], is_array($config['grid_attributes']) ? $config['grid_attributes'] : [])), static fn ($key) => strpos($key, 'attribute:') === 0 && !isset($attrs[$key])));
    }

    /** Category scope is a union, including descendants; missing selections never widen scope. */
    public static function categoryScope(array $config): ?array
    {
        if ($config['source'] !== 'categories') { return null; }
        $ids = [];
        foreach ($config['categories'] as $id) {
            if (!term_exists($id, 'product_cat')) { continue; }
            $ids[] = $id;
            $children = get_term_children($id, 'product_cat');
            if (!is_wp_error($children)) { $ids = array_merge($ids, $children); }
        }
        return array_values(array_unique(array_map('intval', $ids)));
    }

    public static function resolve(array $config): array
    {
        $attrs = self::attributes(); $index = new AttributeIndex(); $filters = [];
        foreach ($config['filters'] as $key) {
            if (!isset($attrs[$key])) { continue; }
            $facet = $index->facet($attrs[$key]['id']);
            if ($facet) {
                $facet['name'] = $attrs[$key]['label'];
                $facet['attribute_id'] = $attrs[$key]['id'];
                $facet['taxonomy'] = $attrs[$key]['taxonomy'];
                $filters[] = $facet;
            }
        }
        return apply_filters('facetcore_resolved_configuration', ['facets' => $filters, 'columns' => [], 'grid_attributes' => [], 'settings' => $config], $config, $attrs);
    }
}