/*
 * QUANTCONNECT.COM - Democratizing Finance, Empowering Individuals.
 * Lean Algorithmic Trading Engine v2.0. Copyright 2025 QuantConnect Corporation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
*/

using System;
using System.Linq;
using NUnit.Framework;
using QuantConnect.Orders;
using System.Collections.Generic;

namespace QuantConnect.Tests.Common.Orders
{
    [TestFixture]
    public class GroupOrderExtensionsTests
    {
        private static IEnumerable<TestCaseData> GroupQuantityTestCases
        {
            get
            {
                yield return new TestCaseData(CreateLegs(1), OrderDirection.Buy, 1).SetDescription("If brokerage returns already calculated quantity");
                yield return new TestCaseData(CreateLegs(-1), OrderDirection.Sell, -1).SetDescription("If brokerage returns already calculated quantity");
                yield return new TestCaseData(CreateLegs(1, -1), OrderDirection.Buy, 1).SetDescription("Bull Call Spread");
                yield return new TestCaseData(CreateLegs(-1, 1), OrderDirection.Sell, -1).SetDescription("Bear Call Spread");
                yield return new TestCaseData(CreateLegs(1, -2, 1), OrderDirection.Buy, 1).SetDescription("Bull Butterfly");
                yield return new TestCaseData(CreateLegs(-1, 2, -1), OrderDirection.Sell, -1).SetDescription("Bear Butterfly");
                yield return new TestCaseData(CreateLegs(1, 1), OrderDirection.Buy, 1).SetDescription("Bull Strangle");
                yield return new TestCaseData(CreateLegs(-1, -1), OrderDirection.Sell, -1).SetDescription("Bear Strangle");
                yield return new TestCaseData(CreateLegs(10, -20, 10), OrderDirection.Buy, 10);
                yield return new TestCaseData(CreateLegs(-10, 20, -10), OrderDirection.Sell, -10);
            }
        }

        [Test, TestCaseSource(nameof(GroupQuantityTestCases))]
        public void GetGroupQuantityByEachLegQuantityShouldReturnExpectedGCD(Leg[] legs, OrderDirection direction, int expected)
        {
            var legQuantities = legs.Select(x => Convert.ToDecimal(x.Quantity));
            var result = GroupOrderExtensions.GetGroupQuantityByEachLegQuantity(legQuantities, direction);
            Assert.AreEqual(Convert.ToDecimal(expected), result);
        }

        private static Leg[] CreateLegs(params int[] quantities) => [.. quantities.Select(q => Leg.Create(null, q))];
    }
}