/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

using LeapInternal;
using NUnit.Framework;
using System;
using System.Runtime.InteropServices;

namespace Leap.LeapCSharp.Tests
{

    [StructLayout(LayoutKind.Sequential)]
    struct TestMarshaledStruct
    {
        public int id;
        public TestMarshaledStruct(int t) { id = t; }
    }

    [TestFixture()]
    public class StructMarshalTests
    {
        public const int ARRAY_SIZE = 5;
        public const int ARRAY_TEST_INDEX = 3;
        public const int TEST_ID = 23;

        private int _size;
        private IntPtr _ptr;
        private TestMarshaledStruct _testStruct;

        [SetUp]
        public void Setup()
        {
            _size = Marshal.SizeOf(typeof(TestMarshaledStruct));
            //For each test, allocate a chunk of memory large enough for [ARRAY_SIZE] structs
            _ptr = Marshal.AllocHGlobal(_size * ARRAY_SIZE);
            _testStruct = new TestMarshaledStruct(TEST_ID);
        }

        [TearDown]
        public void Teardown()
        {
            _size = 0;
            Marshal.FreeHGlobal(_ptr);
            _ptr = IntPtr.Zero;
            _testStruct = new TestMarshaledStruct();
        }

        [Test]
        public void SizeTest()
        {
            int reportedSize = StructMarshal<TestMarshaledStruct>.Size;
            Assert.That(_size, Is.EqualTo(reportedSize), "Size must match Marshal.SizeOf.");
        }

        [Test]
        public void PtrToStructTest()
        {
            Marshal.StructureToPtr(_testStruct, _ptr, false);

            TestMarshaledStruct output;
            StructMarshal<TestMarshaledStruct>.PtrToStruct(_ptr, out output);
            Assert.That(_testStruct.id, Is.EqualTo(output.id), "Input must match output.");
        }

        [Test]
        public void ArrayElementToStructTest()
        {
            Marshal.StructureToPtr(_testStruct, (IntPtr)((long)_ptr + _size * ARRAY_TEST_INDEX), false);

            TestMarshaledStruct output;
            StructMarshal<TestMarshaledStruct>.ArrayElementToStruct(_ptr, ARRAY_TEST_INDEX, out output);
            Assert.That(_testStruct.id, Is.EqualTo(output.id), "Input must match output.");
        }
    }
}