<?php
/**
 * Core: Registers the product type, constants, and utility methods.
 */
defined('ABSPATH') || exit;

class Yoone_Product_Bundles {
    const TYPE = 'yoone_bundle';

    // Post meta keys for configuration
    const META_ALLOWED_PRODUCTS = '_yoone_bundle_allowed_products'; // array<int>
    const META_MIN_QTY          = '_yoone_bundle_min_quantity';     // int
    // 选择模式：include（仅包含列表）、exclude（排除列表，其余全部允许）、all（全部 simple 产品）
    const META_SELECT_MODE      = '_yoone_bundle_select_mode';       // 'include' | 'exclude' | 'all'
    // 旧版：仅支持分类（product_cat）。
    const META_CATEGORIES       = '_yoone_bundle_categories';       // array<int> product_cat term_ids（兼容旧数据）
    // 新版：支持按 taxonomy（product_cat 或 product_tag）进行分组显示
    const META_GROUP_TAXONOMY   = '_yoone_bundle_group_taxonomy';   // 'product_cat' | 'product_tag'
    const META_GROUP_TERMS      = '_yoone_bundle_group_terms';      // array<int> 选中的术语ID（来自所选taxonomy）

    protected static $instance = null;

    public static function instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    private function __construct() {
        // Add "Mix and Match" to the "Product Type" dropdown in the admin.
        add_filter('product_type_selector', array($this, 'register_product_type_in_selector'));
        // Map the type to our class name, so WooCommerce instantiates the correct product object.
        add_filter('woocommerce_product_class', array($this, 'map_product_class'), 10, 2);
    }

    /**
     * Add "Mix and Match" to the "Product Type" dropdown in the admin.
     */
    public function register_product_type_in_selector($types) {
        $types[self::TYPE] = __('Mix and Match (Yoone Bundle)', 'yoone-product-bundles');
        return $types;
    }

    /**
     * Map the type to our class name, so WooCommerce instantiates the correct product object.
     */
    public function map_product_class($classname, $product_type) {
        if ($product_type === self::TYPE) {
            $classname = 'WC_Product_Yoone_Bundle';
        }
        return $classname;
    }

    /**
     * Read and normalize the bundle configuration.
     * @param int|WC_Product $product
     * @return array{allowed_products:int[],min_qty:int,categories:int[]}
     */
    public static function get_bundle_config($product) {
        $product = is_numeric($product) ? wc_get_product($product) : $product;
        if (! $product) return array('allowed_products' => array(), 'min_qty' => 0, 'group_taxonomy' => 'product_cat', 'group_terms' => array());
        $pid = $product->get_id();
        $allowed = get_post_meta($pid, self::META_ALLOWED_PRODUCTS, true);
        $min     = absint(get_post_meta($pid, self::META_MIN_QTY, true));
        $select_mode = get_post_meta($pid, self::META_SELECT_MODE, true);
        $select_mode = in_array($select_mode, array('include','exclude','all'), true) ? $select_mode : 'include';
        // 读取新的分组设置
        $group_tax = get_post_meta($pid, self::META_GROUP_TAXONOMY, true);
        $group_terms = get_post_meta($pid, self::META_GROUP_TERMS, true);
        $group_tax = in_array($group_tax, array('product_cat','product_tag'), true) ? $group_tax : 'product_cat';
        // Keep only simple products (to avoid issues if variations or other types were selected in the backend)
        $allowed = is_array($allowed) ? array_values(array_map('absint', $allowed)) : array();
        if (! empty($allowed)) {
            $simple_only = array();
            foreach ($allowed as $aid) {
                $p = wc_get_product($aid);
                if ($p && $p->is_type('simple')) {
                    $simple_only[] = $aid;
                }
            }
            $allowed = $simple_only;
        }
        // 根据选择模式计算最终 allowed 列表
        if ($select_mode === 'all' || $select_mode === 'exclude') {
            // 获取所有 simple 产品ID（包含任何目录可见性）
            $all_ids = wc_get_products(array(
                'type'               => array('simple'),
                'status'             => array('publish'),
                'catalog_visibility' => 'any',
                'limit'              => -1,
                'return'             => 'ids',
            ));
            $all_ids = is_array($all_ids) ? array_values(array_map('absint', $all_ids)) : array();
            if ($select_mode === 'all') {
                $allowed = $all_ids; // 全部 simple 产品
            } else {
                // exclude 模式：从全部 simple 产品中排除配置列表
                $allowed = array_values(array_diff($all_ids, $allowed));
            }
        } // include 模式：保持 allowed 原样
        // 兼容旧版：如果未配置新术语，但存在旧的分类设置，则沿用分类
        if (empty($group_terms)) {
            $cats = get_post_meta($pid, self::META_CATEGORIES, true);
            $group_terms = is_array($cats) ? array_values(array_map('absint', $cats)) : array();
            $group_tax = 'product_cat';
        } else {
            $group_terms = is_array($group_terms) ? array_values(array_map('absint', $group_terms)) : array();
        }
        return array(
            'allowed_products' => $allowed,
            'min_qty'          => max(0, $min),
            'select_mode'      => $select_mode,
            'group_taxonomy'   => $group_tax,
            'group_terms'      => $group_terms,
        );
    }
}