<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

/**
 * 小程序购物车模型（门店订货车：按用户归属，同商品唯一行、加购合并数量）
 */
class CartModel extends Model
{
    use HasFactory;

    protected $table = 'cart';
    protected $primaryKey = 'id';

    protected $fillable = [
        'user_id',
        'product_id',
        'quantity',
    ];

    protected $casts = [
        'user_id' => 'integer',
        'product_id' => 'integer',
        'quantity' => 'decimal:2',
    ];

    /**
     * 归属用户
     */
    public function user(): BelongsTo
    {
        return $this->belongsTo(UserModel::class, 'user_id', 'id');
    }

    /**
     * 购物车商品（软删除后为 null；列表接口需 withTrashed 自行判断状态）
     */
    public function product(): BelongsTo
    {
        return $this->belongsTo(ProductModel::class, 'product_id', 'id');
    }
}