<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     * 小程序购物车（门店订货车）：按用户归属，同商品唯一行、加购合并累加
     */
    public function up(): void
    {
        if (! Schema::hasTable('cart')) {
            Schema::create('cart', function (Blueprint $table) {
                $table->increments('id')->comment('购物车项ID');
                $table->integer('user_id')->comment('用户ID（购物车归属者）');
                $table->integer('product_id')->comment('商品ID');
                $table->decimal('quantity', 10, 2)->default(0)->comment('订货量');
                $table->timestamps();
                $table->unique(['user_id', 'product_id'], 'cart_user_product_unique');
                $table->index(['user_id', 'created_at'], 'cart_user_created_index');
                $table->comment('小程序购物车表（门店订货车）');
            });
        }
    }

    /**
     * Reverse the migrations.
     */
    public function down(): void
    {
        Schema::dropIfExists('cart');
    }
};