<?php

namespace App\Module\Shop\Models;

use App\Module\Shop\Enums\PURCHASE_LIMIT_PERIOD;
use App\Module\Shop\Enums\PURCHASE_LIMIT_TYPE;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\Relations\HasMany;
use UCore\ModelCore;

/**
 * 商店限购配置模型
 *
 * field start 
 * @property  int  $id  限购配置ID，主键
 * @property  int  $shop_item_id  商品ID，外键关联kku_shop_items表
 * @property  \App\Module\Shop\Enums\PURCHASE_LIMIT_TYPE  $limit_type  限购类型（1:单次购买限制, 2:周期性购买限制）
 * @property  \App\Module\Shop\Enums\PURCHASE_LIMIT_PERIOD  $limit_period  限购周期（0:永久, 1:每日, 2:每周, 3:每月, 4:每年）
 * @property  int  $max_quantity  最大购买数量
 * @property  string  $name  限购规则名称
 * @property  string  $description  限购规则描述
 * @property  bool  $is_active  是否激活（0:否, 1:是）
 * @property  int  $sort_order  排序权重
 * @property  \Carbon\Carbon  $created_at  创建时间
 * @property  \Carbon\Carbon  $updated_at  更新时间
 * field end
 */
class ShopPurchaseLimit extends ModelCore
{
    /**
     * 与模型关联的表名
     *
     * @var string
     */
    protected $table = 'shop_purchase_limits';

    /**
     * 可批量赋值的属性
     *
     * @var array
     */
    protected $fillable = [
        'shop_item_id',
        'limit_type',
        'limit_period',
        'max_quantity',
        'name',
        'description',
        'is_active',
        'sort_order',
    ];

    /**
     * 应该被转换为原生类型的属性
     *
     * @var array
     */
    protected $casts = [
        'is_active' => 'boolean',
        'limit_type' => PURCHASE_LIMIT_TYPE::class,
        'limit_period' => PURCHASE_LIMIT_PERIOD::class,
    ];

    /**
     * 获取关联的商品
     *
     * @return BelongsTo
     */
    public function shopItem(): BelongsTo
    {
        return $this->belongsTo(ShopItem::class, 'shop_item_id');
    }

    /**
     * 获取用户购买计数记录
     *
     * @return HasMany
     */
    public function userCounters(): HasMany
    {
        return $this->hasMany(ShopUserPurchaseCounter::class, 'limit_id');
    }

    /**
     * 获取用户在此限购规则下的购买计数
     *
     * @param int $userId 用户ID
     * @return int 购买计数
     */
    public function getUserPurchaseCount(int $userId): int
    {
        $counter = $this->userCounters()
            ->where('user_id', $userId)
            ->first();

        if (!$counter) {
            return 0;
        }

        // 检查是否需要重置计数
        if ($this->limit_period->shouldReset($counter->last_reset_time)) {
            $counter->resetCount();
            return 0;
        }

        return $counter->current_count;
    }

    /**
     * 增加用户购买计数
     *
     * @param int $userId 用户ID
     * @param int $quantity 购买数量
     * @return bool
     */
    public function incrementUserPurchaseCount(int $userId, int $quantity = 1): bool
    {
        $counter = ShopUserPurchaseCounter::firstOrCreate(
            [
                'limit_id' => $this->id,
                'user_id' => $userId,
            ],
            [
                'current_count' => 0,
                'last_reset_time' => now(),
            ]
        );

        // 检查是否需要重置计数
        if ($this->limit_period->shouldReset($counter->last_reset_time)) {
            $counter->resetCount();
        }

        $counter->current_count += $quantity;
        return $counter->save();
    }

    /**
     * 检查用户是否可以购买指定数量
     *
     * @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 canUserPurchase(int $userId, int $quantity): array
    {
        if (!$this->is_active) {
            return [true, '', $this->max_quantity]; // 限购规则未激活，不限制
        }

        $currentCount = $this->getUserPurchaseCount($userId);
        $remainingQuantity = $this->max_quantity - $currentCount;

        if ($quantity > $remainingQuantity) {
            $periodName = $this->limit_period->getName($this->limit_period->value);
            $typeName = $this->limit_type->getName($this->limit_type->value);
            
            $message = match ($this->limit_type) {
                PURCHASE_LIMIT_TYPE::SINGLE_PURCHASE => "单次购买数量不能超过{$this->max_quantity}个",
                PURCHASE_LIMIT_TYPE::PERIODIC_PURCHASE => "{$periodName}内最多购买{$this->max_quantity}个，剩余可购买{$remainingQuantity}个",
            };

            return [false, $message, $remainingQuantity];
        }

        return [true, '', $remainingQuantity];
    }

    /**
     * 获取限购类型文本
     *
     * @return string
     */
    public function getLimitTypeTextAttribute(): string
    {
        return $this->limit_type->getName($this->limit_type->value);
    }

    /**
     * 获取限购周期文本
     *
     * @return string
     */
    public function getLimitPeriodTextAttribute(): string
    {
        return $this->limit_period->getName($this->limit_period->value);
    }
}