<?php

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

return new class extends Migration
{
    public function up(): void
    {
        Schema::table('invoice_items', function (Blueprint $table) {
            // No FK on product_variant_id — matches product_id's existing
            // convention on this table.
            $table->unsignedBigInteger('product_variant_id')->nullable()->after('product_id');
            $table->foreignId('unit_id')->nullable()->after('product_variant_id')->constrained('unit_of_measures')->nullOnDelete();
            $table->index('product_variant_id');
        });
    }

    public function down(): void
    {
        Schema::table('invoice_items', function (Blueprint $table) {
            $table->dropForeign(['unit_id']);
            $table->dropIndex(['product_variant_id']);
            $table->dropColumn(['product_variant_id', 'unit_id']);
        });
    }
};
