<?php

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

return new class extends Migration
{
    /**
     * Run the migrations.
     */
    public function up(): void
    {
        // 倉庫基本資料
        Schema::create('warehouses', function (Blueprint $table) {
            $table->id();
            $table->string('code', 50)->unique()->comment('倉庫編號');
            $table->string('name', 50)->comment('倉庫名稱');
            $table->string('address')->nullable()->comment('地址');
            $table->text('description')->nullable()->comment('描述');
            $table->timestamps();
        });

        // 商品庫存詳情
        Schema::create('inventories', function (Blueprint $table) {
            $table->id();
            $table->foreignId('warehouse_id')->constrained()->onDelete('cascade');
            $table->foreignId('product_id')->constrained()->onDelete('restrict');
            $table->decimal('quantity', 10, 2)->default(0)->comment('當前庫存數量');
            $table->decimal('safety_stock', 10, 2)->default(0)->nullable()->comment('安全存量');
            $table->string('location', 50)->nullable()->comment('儲位/貨架號');
            $table->timestamps();

            $table->unique(['warehouse_id', 'product_id'], 'warehouse_product_unique');
        });

        // 庫存異動紀錄
        Schema::create('inventory_transactions', function (Blueprint $table) {
            $table->id();
            $table->foreignId('inventory_id')->constrained()->onDelete('cascade');
            $table->string('type', 20)->comment('異動類型: purchase_in, sales_out, adjustment, transfer_in, transfer_out');
            $table->decimal('quantity', 10, 2)->comment('異動數量 (+/-)');
            $table->decimal('balance_before', 10, 2)->comment('異動前餘額');
            $table->decimal('balance_after', 10, 2)->comment('異動後餘額');
            $table->string('reason')->nullable()->comment('異動原因/備註');
            $table->nullableMorphs('reference'); // reference_type, reference_id
            $table->foreignId('user_id')->nullable()->constrained()->onDelete('set null')->comment('操作人員');
            $table->timestamps();
        });
    }

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