<?php
/**
 * 核心：订阅计划配置的读写与工具函数。
 *
 * @package Yoone_Subscriptions
 */
defined('ABSPATH') || exit;

class Yoone_Subscriptions {
    // postmeta 键名
    const META_ENABLED       = '_yoone_sub_enabled';        // bool
    const META_PERIOD        = '_yoone_sub_period';         // 'month'|'year'
    const META_QTY_DEFAULT   = '_yoone_sub_qty_default';    // int >=1
    const META_PRICE         = '_yoone_sub_price';          // decimal string
    const META_ALLOW_ONETIME = '_yoone_sub_allow_onetime';  // bool
    const META_MIN_QTY       = '_yoone_sub_min_qty';        // int >=1（最小起订量，仅订阅模式下生效）
    const META_TIER_RULES    = '_yoone_sub_tier_rules';     // string 逗号分隔“数量:折扣%”对，如 10:5,20:10
    // 新增：多订阅计划（每个计划包含：id、label、period、price、discount_percent 可选）
    const META_PLANS         = '_yoone_sub_plans';          // serialized array

    protected static $instance = null;

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

    private function __construct() {
        // 无需在此注册产品类型；订阅计划作为 simple/product 的增强配置存在
    }

    /**
     * 获取产品的订阅配置（规范化）。
     *
     * @param int|WC_Product $product 产品或产品ID
     * @return array{enabled:bool,period:string,qty_default:int,price:float,allow_onetime:bool}
     */
    public static function get_config($product) {
        $product = is_numeric($product) ? wc_get_product($product) : $product;
        if (! $product) return self::defaults();
        $pid = $product->get_id();
        $enabled = (bool) get_post_meta($pid, self::META_ENABLED, true);
        $period  = get_post_meta($pid, self::META_PERIOD, true);
        $qty     = absint(get_post_meta($pid, self::META_QTY_DEFAULT, true));
        $price   = get_post_meta($pid, self::META_PRICE, true);
        $onetime = (bool) get_post_meta($pid, self::META_ALLOW_ONETIME, true);
        $min_qty = absint(get_post_meta($pid, self::META_MIN_QTY, true));
        $tiers   = get_post_meta($pid, self::META_TIER_RULES, true);
        $plans   = get_post_meta($pid, self::META_PLANS, true);
        $period  = in_array($period, array('month','year'), true) ? $period : 'month';
        $qty     = max(1, $qty);
        $price   = is_numeric($price) ? floatval($price) : 0.0; // 0 表示按产品原价
        // 规范化计划数组
        if (! is_array($plans)) {
            $plans = array();
        } else {
            $norm = array();
            foreach ($plans as $p) {
                $norm[] = array(
                    'id'               => isset($p['id']) ? sanitize_key($p['id']) : uniqid('plan_'),
                    'label'            => isset($p['label']) ? sanitize_text_field($p['label']) : __('订阅计划', 'yoone-subscriptions'),
                    'period'           => (isset($p['period']) && in_array($p['period'], array('month','year'), true)) ? $p['period'] : 'month',
                    'price'            => isset($p['price']) && is_numeric($p['price']) ? floatval($p['price']) : 0.0,
                    'discount_percent' => isset($p['discount_percent']) && is_numeric($p['discount_percent']) ? floatval($p['discount_percent']) : 0.0,
                );
            }
            $plans = $norm;
        }
        return array(
            'enabled'       => $enabled,
            'period'        => $period,
            'qty_default'   => $qty,
            'price'         => $price,
            'allow_onetime' => $onetime,
            'min_qty'       => max(1, $min_qty),
            'tier_rules'    => is_string($tiers) ? $tiers : '',
            'plans'         => $plans,
        );
    }

    /**
     * 默认配置
     */
    public static function defaults() {
        return array(
            'enabled'       => false,
            'period'        => 'month',
            'qty_default'   => 1,
            'price'         => 0.0,
            'allow_onetime' => true,
            'min_qty'       => 1,
            'tier_rules'    => '',
            'plans'         => array(),
        );
    }

    /**
     * 周期对应的系数（用于价格计算）。
     * month=1, year=12。
     */
    public static function period_factor($period) {
        return $period === 'year' ? 12 : 1;
    }
}