<?php

namespace App\Module\Shop\Models;

use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\BelongsToMany;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Support\Facades\DB;
use UCore\ModelCore;
use App\Module\Shop\Models\ShopCategory;
use App\Module\Shop\Models\ShopPromotion;
use App\Module\Shop\Models\ShopPromotionItem;
use App\Module\Shop\Models\ShopPurchaseLog;

/**
 * 商店物品模型
 *
 * field start 
 * @property  int  $id  商品ID，主键
 * @property  string  $name  商品名称
 * @property  string  $description  商品描述
 * @property  int  $category_id  分类ID，外键关联kku_shop_categories表
 * @property  string  $category_name  分类名称（字符串格式，区别于现有分类机制）
 * @property  int  $consume_group_id  消耗组ID，外键关联kku_game_consume_groups表
 * @property  int  $reward_group_id  奖励组ID，外键关联kku_game_reward_groups表
 * @property  int  $max_single_buy  单次最大购买数量（0表示无限制）
 * @property  bool  $is_active  是否激活（0:否, 1:是）
 * @property  int  $sort_order  排序权重
 * @property  \App\Module\Shop\Casts\ShopDisplayAttributesCast  $display_attributes  展示属性，以JSON格式存储键值对，用于界面展示和描述的属性
 * @property  string  $start_time  上架时间
 * @property  string  $end_time  下架时间
 * @property  \Carbon\Carbon  $created_at  创建时间
 * @property  \Carbon\Carbon  $updated_at  更新时间
 * field end
 */
class ShopItem extends ModelCore
{
    /**
     * 与模型关联的表名
     *
     * @var string
     */
    protected $table = 'shop_items';

    /**
     * 可批量赋值的属性
     *
     * @var array
     */
    protected $fillable = [
        'name',
        'description',
        'category_id',
        'category_name',
        'consume_group_id',
        'reward_group_id',
        'max_single_buy',
        'is_active',
        'sort_order',
        'display_attributes',
        'start_time',
        'end_time',
    ];

    /**
     * 应该被转换为日期的属性
     *
     * @var array
     */
    protected $dates = [
        'start_time',
        'end_time',
        'created_at',
        'updated_at',
    ];

    /**
     * 应该被转换为原生类型的属性
     *
     * @var array
     */
    protected $casts = [
        'is_active' => 'boolean',
        'display_attributes' => \App\Module\Shop\Casts\ShopDisplayAttributesCast::class,
    ];

    /**
     * 获取关联的分类
     *
     * @return BelongsTo
     */
    public function category(): BelongsTo
    {
        return $this->belongsTo(ShopCategory::class, 'category_id');
    }

    /**
     * 获取关联的消耗组
     *
     * @return BelongsTo
     */
    public function consumeGroup(): BelongsTo
    {
        return $this->belongsTo(\App\Module\Game\Models\GameConsumeGroup::class, 'consume_group_id');
    }

    /**
     * 获取关联的奖励组
     *
     * @return BelongsTo
     */
    public function rewardGroup(): BelongsTo
    {
        return $this->belongsTo(\App\Module\Game\Models\GameRewardGroup::class, 'reward_group_id');
    }

    /**
     * 获取用户已购买数量
     *
     * @param int $userId 用户ID
     * @return int 已购买数量
     */
    public function getUserBoughtCount(int $userId): int
    {
        return ShopPurchaseLog::where('user_id', $userId)
            ->where('shop_item_id', $this->id)
            ->sum('quantity');
    }

    /**
     * 获取该商品关联的促销活动
     *
     * @return BelongsToMany
     */
    public function promotions(): BelongsToMany
    {
        return $this->belongsToMany(
            ShopPromotion::class,
            'shop_promotion_items',
            'shop_item_id',
            'promotion_id'
        )->withPivot('custom_discount_value')
        ->withTimestamps();
    }

    /**
     * 获取商品的促销关联记录
     *
     * @return HasMany
     */
    public function promotionItems(): HasMany
    {
        return $this->hasMany(ShopPromotionItem::class, 'shop_item_id');
    }

    /**
     * 获取当前有效的促销活动
     *
     * @return ShopPromotion|null
     */
    public function getActivePromotion(): ?ShopPromotion
    {
        $now = now();

        return $this->promotions()
            ->where('is_active', true)
            ->where(function ($query) use ($now) {
                $query->whereNull('start_time')
                    ->orWhere('start_time', '<=', $now);
            })
            ->where(function ($query) use ($now) {
                $query->whereNull('end_time')
                    ->orWhere('end_time', '>=', $now);
            })
            ->orderBy('sort_order')
            ->first();
    }

    /**
     * 获取折扣后的价格
     * 注意：由于商品不再有固定价格，此方法需要根据消耗组重新实现
     *
     * @return int
     */
    public function getDiscountedPrice(): int
    {
        // TODO: 根据消耗组重新实现价格计算逻辑
        $promotion = $this->getActivePromotion();

        if (!$promotion) {
            return 0; // 暂时返回0，需要根据消耗组计算
        }

        $promotionItem = $this->promotionItems()
            ->where('promotion_id', $promotion->id)
            ->first();

        $customDiscountValue = $promotionItem ? $promotionItem->custom_discount_value : null;

        return $promotion->calculateDiscountedPrice(0, $customDiscountValue); // 暂时传入0
    }

    /**
     * 记录购买记录
     * 注意：由于商品结构变更，此方法需要根据新的消耗组和奖励组重新实现
     *
     * @param int $userId 用户ID
     * @param int $quantity 购买数量
     * @param int $totalPrice 总价
     * @return ShopPurchaseLog 购买记录
     */
    public function recordPurchase(int $userId, int $quantity, int $totalPrice): ShopPurchaseLog
    {
        $log = new ShopPurchaseLog([
            'user_id' => $userId,
            'shop_item_id' => $this->id,
            'item_id' => null, // 不再关联单一物品
            'quantity' => $quantity,
            'price' => 0, // 不再有固定价格
            'total_price' => $totalPrice,
            'currency_id' => null, // 不再有单一货币类型
            'purchase_time' => now(),
            'ip_address' => request()->ip(),
            'device_info' => request()->userAgent(),
        ]);

        $log->save();

        return $log;
    }

    /**
     * 获取关联的限购配置
     *
     * @return HasMany
     */
    public function purchaseLimits(): HasMany
    {
        return $this->hasMany(ShopPurchaseLimit::class, 'shop_item_id');
    }

    /**
     * 获取激活的限购配置
     *
     * @return HasMany
     */
    public function activePurchaseLimits(): HasMany
    {
        return $this->purchaseLimits()->where('is_active', true)->orderBy('sort_order');
    }

    /**
     * 检查用户是否可以购买指定数量（包含所有限购规则）
     *
     * @param int $userId 用户ID
     * @param int $quantity 购买数量
     * @return array [是否可购买, 错误消息, 剩余可购买数量]
     */
    public function canUserPurchaseWithLimits(int $userId, int $quantity): array
    {
        // 检查单次购买限制
        if ($this->max_single_buy > 0 && $quantity > $this->max_single_buy) {
            return [false, "单次购买数量不能超过{$this->max_single_buy}个", $this->max_single_buy];
        }

        // 检查所有激活的限购配置
        $activeLimits = $this->activePurchaseLimits;
        $minRemainingQuantity = PHP_INT_MAX;

        foreach ($activeLimits as $limit) {
            list($canPurchase, $errorMessage, $remainingQuantity) = $limit->canUserPurchase($userId, $quantity);

            if (!$canPurchase) {
                return [false, $errorMessage, $remainingQuantity];
            }

            $minRemainingQuantity = min($minRemainingQuantity, $remainingQuantity);
        }

        $finalRemainingQuantity = $minRemainingQuantity === PHP_INT_MAX ? $quantity : $minRemainingQuantity;
        return [true, '', $finalRemainingQuantity];
    }

    /**
     * 更新所有相关的限购计数
     *
     * @param int $userId 用户ID
     * @param int $quantity 购买数量
     * @return bool
     */
    public function updatePurchaseLimitCounters(int $userId, int $quantity): bool
    {
        $activeLimits = $this->activePurchaseLimits;

        foreach ($activeLimits as $limit) {
            $limit->incrementUserPurchaseCount($userId, $quantity);
        }

        return true;
    }
}