<?php
/**
 * AKSRT Shop Product Service
 *
 * Variant and product-meta helpers extracted from AKSRT_Shop.
 *
 * @package AKSRT
 */

defined('ABSPATH') || exit;

class AKSRT_Shop_Product_Service {

    private AKSRT_Shop $shop;

    public function __construct(AKSRT_Shop $shop) {
        $this->shop = $shop;
    }

    /* ============================================================
     * Product meta helpers
     * ============================================================ */

    public function get_term_options(string $taxonomy): array {
        $terms = get_terms([
            'taxonomy' => $taxonomy,
            'hide_empty' => false,
            'orderby' => 'name',
            'order' => 'ASC',
        ]);

        if (is_wp_error($terms) || empty($terms)) {
            return [];
        }

        return array_map(static function ($term) {
            return [
                'id' => (int) $term->term_id,
                'name' => (string) $term->name,
            ];
        }, $terms);
    }

    public function get_product_gallery(int $product_id): array {
        $gallery = get_post_meta($product_id, '_aksrt_product_gallery', true);
        if (!is_array($gallery)) {
            return [];
        }

        return array_values(array_filter(array_map('esc_url_raw', $gallery)));
    }

    public function get_product_shipping_profile(int $product_id): array {
        return [
            'mode' => sanitize_key((string) get_post_meta($product_id, '_aksrt_shipping_mode', true)) ?: 'express',
            'fee' => (float) get_post_meta($product_id, '_aksrt_shipping_fee', true),
            'delivery_note' => (string) get_post_meta($product_id, '_aksrt_delivery_note', true),
        ];
    }

    public function get_product_after_sale_profile(int $product_id): array {
        return [
            'policy' => (string) get_post_meta($product_id, '_aksrt_after_sale_policy', true),
            'support_refund' => get_post_meta($product_id, '_aksrt_support_refund', true) !== '0',
        ];
    }

    public function get_product_marketing_profile(int $product_id): array {
        return [
            'headline' => (string) get_post_meta($product_id, '_aksrt_marketing_headline', true),
            'shipping_tip' => (string) get_post_meta($product_id, '_aksrt_shipping_tip', true),
            'service_tip' => (string) get_post_meta($product_id, '_aksrt_service_tip', true),
        ];
    }

    public function get_payment_method_options(): array {
        $methods = [];

        if (class_exists('AKSRT_Payment_Gateway')) {
            foreach (AKSRT_Payment_Gateway::get_instance()->get_all() as $id => $gateway) {
                if (!method_exists($gateway, 'is_configured') || !$gateway->is_configured()) {
                    continue;
                }
                $methods[$id] = [
                    'value'       => $id,
                    'label'       => method_exists($gateway, 'get_name') ? (string) $gateway->get_name() : $id,
                    'description' => $this->gateway_method_description((string) $id),
                ];
            }
        }

        if (class_exists('AKSRT_Settings') && AKSRT_Settings::credits_enabled()) {
            $methods['points'] = [
                'value'       => 'points',
                'label'       => __('积分兑换', 'aksrt'),
                'description' => __('使用积分购买积分商品。', 'aksrt'),
            ];
        }

        $manual = true;
        if (class_exists('AKSRT_Settings')) {
            $gw = AKSRT_Settings::get_payment_gateway_settings();
            $manual = !empty($gw['manual_review']) || ($gw['mode'] ?? '') === 'manual_review';
        }
        if ($manual) {
            $methods['manual_review'] = [
                'value'       => 'manual_review',
                'label'       => __('人工确认', 'aksrt'),
                'description' => __('保留待支付订单，后续由管理员确认。', 'aksrt'),
            ];
        }

        if (empty($methods)) {
            $methods['manual_review'] = [
                'value'       => 'manual_review',
                'label'       => __('人工确认', 'aksrt'),
                'description' => __('保留待支付订单，后续由管理员确认。', 'aksrt'),
            ];
        }

        return $methods;
    }

    private function gateway_method_description(string $id): string {
        switch ($id) {
            case 'balance':
                return __('即时完成支付并写回订单状态。', 'aksrt');
            case 'alipay':
                return __('跳转支付宝完成支付。', 'aksrt');
            case 'wechatpay':
                return __('微信扫码或跳转完成支付。', 'aksrt');
            case 'paypal':
                return __('跳转 PayPal 完成支付。', 'aksrt');
            case 'stripe':
                return __('跳转 Stripe Checkout 完成支付。', 'aksrt');
            default:
                return '';
        }
    }

    public function get_shipping_method_options(): array {
        return [
            'express' => [
                'value' => 'express',
                'label' => __('快递配送', 'aksrt'),
                'description' => __('标准快递，支持物流跟踪。', 'aksrt'),
                'fee' => 12.0,
            ],
            'ems' => [
                'value' => 'ems',
                'label' => __('EMS', 'aksrt'),
                'description' => __('偏远地区可选。', 'aksrt'),
                'fee' => 18.0,
            ],
            'download' => [
                'value' => 'download',
                'label' => __('自动发货', 'aksrt'),
                'description' => __('适用于数字商品。', 'aksrt'),
                'fee' => 0.0,
            ],
        ];
    }

    public function get_limit_buy_config(int $product_id): array {
        $raw = get_post_meta($product_id, '_aksrt_limit_buy_config', true);
        if (!is_array($raw)) {
            $legacy = (int) get_post_meta($product_id, '_aksrt_limit_buy', true);
            return ['default' => $legacy > 0 ? $legacy : -1, 'desc' => ''];
        }
        return [
            'default' => (int) ($raw['default'] ?? -1),
            'vip'     => (int) ($raw['vip'] ?? -1),
            'vip2'    => (int) ($raw['vip2'] ?? -1),
            'auth'    => (int) ($raw['auth'] ?? -1),
            'desc'    => sanitize_text_field((string) ($raw['desc'] ?? '')),
        ];
    }

    public function get_product_services(int $product_id): array {
        $raw = get_post_meta($product_id, '_aksrt_services', true);
        if (!is_array($raw)) return [];
        return array_values(array_filter(array_map(static function ($s) {
            $name = sanitize_text_field((string) ($s['name'] ?? ''));
            if ($name === '') return null;
            return [
                'name' => $name,
                'desc' => sanitize_text_field((string) ($s['desc'] ?? '')),
                'icon' => esc_url_raw((string) ($s['icon'] ?? '')),
            ];
        }, $raw)));
    }

    public function get_product_params(int $product_id): array {
        $raw = get_post_meta($product_id, '_aksrt_product_params', true);
        if (!is_array($raw)) return [];
        return array_values(array_filter(array_map(static function ($p) {
            $name = sanitize_text_field((string) ($p['name'] ?? ''));
            if ($name === '') return null;
            return [
                'name'  => $name,
                'value' => sanitize_text_field((string) ($p['value'] ?? '')),
            ];
        }, $raw)));
    }

    /**
     * Resolve product main image with 3-tier fallback:
     * 1. _aksrt_product_image (custom main image)
     * 2. WordPress featured image (post thumbnail)
     * 3. First gallery image from _aksrt_product_gallery
     */
    public function resolve_main_image(int $product_id): string {
        $custom = (string) get_post_meta($product_id, '_aksrt_product_image', true);
        if ($custom !== '') {
            return esc_url_raw($custom);
        }
        $thumb = get_the_post_thumbnail_url($product_id, 'large');
        if ($thumb) {
            return (string) $thumb;
        }
        $gallery = get_post_meta($product_id, '_aksrt_product_gallery', true);
        if (is_array($gallery) && !empty($gallery)) {
            $first = reset($gallery);
            if ($first) {
                return esc_url_raw((string) $first);
            }
        }
        return '';
    }

    public function build_product_card_view(int $product_id): array {
        $post = get_post($product_id);
        if (!$post || $post->post_type !== 'aksrt_product') {
            return [];
        }

        $stock_raw = (int) get_post_meta($product_id, '_aksrt_stock', true);
        $is_unlimited = $stock_raw <= -1;

        return [
            'id' => $product_id,
            'title' => (string) get_the_title($product_id),
            'excerpt' => (string) get_the_excerpt($product_id),
            'price' => (float) get_post_meta($product_id, '_aksrt_price', true),
            'image' => $this->resolve_main_image($product_id),
            'stock' => $stock_raw,
            'is_unlimited' => $is_unlimited,
            'sales' => (int) get_post_meta($product_id, '_aksrt_sales', true),
            'status' => (string) get_post_status($product_id),
            'created' => get_the_date('Y-m-d H:i', $product_id),
            'permalink' => get_permalink($product_id) ?: '',
        ];
    }

    /* ============================================================
     * Product Variants / SKU
     * ============================================================ */

    /**
     * Get variants table name.
     */
    public function variants_table(): string {
        global $wpdb;
        return $wpdb->prefix . 'aksrt_product_variant';
    }

    /**
     * Get all variants for a product.
     */
    public function get_variants(int $product_id): array {
        global $wpdb;
        $rows = $wpdb->get_results($wpdb->prepare(
            "SELECT * FROM {$this->variants_table()} WHERE product_id = %d ORDER BY sort_order ASC, id ASC",
            $product_id
        ), ARRAY_A);

        if (!$rows) return [];

        return array_map(function ($row) {
            $row['id'] = (int) $row['id'];
            $row['product_id'] = (int) $row['product_id'];
            $row['price'] = (float) $row['price'];
            $row['stock'] = (int) $row['stock'];
            $row['sort_order'] = (int) $row['sort_order'];
            $row['attributes'] = json_decode($row['attributes'] ?? '[]', true) ?: [];
            return $row;
        }, $rows);
    }

    /**
     * Get a single variant by ID.
     */
    public function get_variant(int $variant_id): ?array {
        global $wpdb;
        $row = $wpdb->get_row($wpdb->prepare(
            "SELECT * FROM {$this->variants_table()} WHERE id = %d",
            $variant_id
        ), ARRAY_A);
        if (!$row) return null;
        $row['id'] = (int) $row['id'];
        $row['product_id'] = (int) $row['product_id'];
        $row['price'] = (float) $row['price'];
        $row['stock'] = (int) $row['stock'];
        $row['attributes'] = json_decode($row['attributes'] ?? '[]', true) ?: [];
        return $row;
    }

    /**
     * Save variants for a product (replace all).
     */
    public function save_variants(int $product_id, array $variants): array {
        global $wpdb;
        $table = $this->variants_table();

        // Delete existing variants
        $wpdb->delete($table, ['product_id' => $product_id]);

        $saved = [];
        foreach ($variants as $index => $v) {
            $data = [
                'product_id' => $product_id,
                'sku'        => sanitize_text_field((string) ($v['sku'] ?? '')),
                'attributes' => wp_json_encode($v['attributes'] ?? []),
                'price'      => max(0, (float) ($v['price'] ?? 0)),
                'stock'      => max(0, (int) ($v['stock'] ?? 0)),
                'image'      => esc_url_raw((string) ($v['image'] ?? '')),
                'sort_order' => $index,
                'created_at' => current_time('mysql', true),
            ];
            $wpdb->insert($table, $data);
            $saved[] = array_merge($data, ['id' => (int) $wpdb->insert_id]);
        }

        // Update product meta flag
        update_post_meta($product_id, '_aksrt_has_variants', count($saved) > 0 ? '1' : '0');

        return $saved;
    }

    /**
     * Delete a single variant.
     */
    public function delete_variant(int $variant_id): bool {
        global $wpdb;
        $variant = $this->get_variant($variant_id);
        if (!$variant) return false;

        $result = $wpdb->delete($this->variants_table(), ['id' => $variant_id]);
        if ($result) {
            // Update product meta flag
            $remaining = $wpdb->get_var($wpdb->prepare(
                "SELECT COUNT(*) FROM {$this->variants_table()} WHERE product_id = %d",
                $variant['product_id']
            ));
            update_post_meta($variant['product_id'], '_aksrt_has_variants', $remaining > 0 ? '1' : '0');
        }
        return (bool) $result;
    }

    /**
     * Check if a product has variants.
     */
    public function has_variants(int $product_id): bool {
        return get_post_meta($product_id, '_aksrt_has_variants', true) === '1';
    }
}