/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * Licensed under the Oculus SDK License Agreement (the "License");
 * you may not use the Oculus SDK except in compliance with the License,
 * which is provided at the time of installation or download, or which
 * otherwise accompanies this software in either electronic or hard copy form.
 *
 * You may obtain a copy of the License at
 *
 * https://developer.oculus.com/licenses/oculussdk/
 *
 * Unless required by applicable law or agreed to in writing, the Oculus SDK
 * 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.Collections;
using UnityEngine;
using NUnit.Framework;
using UnityEngine.TestTools;
using System.Collections.Generic;

namespace Meta.XR.MRUtilityKit.Tests
{
    public class TriangulatorTests : MRUKTestBase
    {
        [UnitySetUp]
        public IEnumerator SetUp()
        {
            MRUKNative.LoadMRUKSharedLibrary();
            yield return null;
        }

        [UnityTearDown]
        public IEnumerator TearDown()
        {
            MRUKNative.FreeMRUKSharedLibrary();
            yield return null;
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate a simple quad
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateQuad()
        {
            var vertices = new List<Vector2> { new(0f, 0f), new(1f, 0f), new(1f, 1f), new(0f, 1f) };
            Triangulator.TriangulatePoints(vertices, null, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(6, indices.Length);
            Assert.AreEqual(1.0f, TestUtilities.CalculateTriangulatedArea(outVertices, indices));
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate a 2x2 quad with a 1x1 quad hole in the center of it
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateQuadWithHole()
        {
            var vertices = new List<Vector2> { new(0f, 0f), new(2f, 0f), new(2f, 2f), new(0f, 2f) };
            var holes = new List<List<Vector2>> { new List<Vector2> { new(0.5f, 0.5f), new(0.5f, 1.5f), new(1.5f, 1.5f), new(1.5f, 0.5f) } };
            Triangulator.TriangulatePoints(vertices, holes, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(24, indices.Length);
            Assert.AreEqual(3.0f, TestUtilities.CalculateTriangulatedArea(outVertices, indices));
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate a large quad with 2 large holes in it.
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateQuadWith2HolesLarge()
        {
            var vertices = new List<Vector2> {
                new(101.985214f, 113.8258f), new(-101.985214f, 113.8258f), new(-101.985214f, -113.8258f), new(101.985214f, -113.8258f)
            };
            var holes = new List<List<Vector2>> {
                new List<Vector2> { new(18.395055731633885f, 9.0596833f), new(-72.518264268366110f, 9.0596833f), new(-72.518264268366110f, 67.2252527f), new(18.395055731633885f, 67.2252527f) },
                new List<Vector2> { new(18.395055731633885f, -53.4203167f), new(-72.518264268366110f, -53.4203167f), new(-72.518264268366110f, 4.7452569f), new(18.395055731633885f, 4.7452569f) },
            };
            Triangulator.TriangulatePoints(vertices, holes, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(42, indices.Length);
            Assert.AreEqual(35858.1445f, TestUtilities.CalculateTriangulatedArea(outVertices, indices), 0.01f);
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate a 4x4 quad with four 1x1 quad holes distributed in a grid pattern
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateQuadWith4Holes()
        {
            var vertices = new List<Vector2> { new(0f, 0f), new(4f, 0f), new(4f, 4f), new(0f, 4f) };
            var holes = new List<List<Vector2>>();
            for (int i = 0; i < 4; i++)
            {
                var offset = new Vector2(0.5f + 2f * (i / 2), 0.5f + 2f * (i % 2));
                // Add slight offset to prevent triangulation algorithm from "optimizing" the mesh by combining multiple triangles together
                offset.x += i * 0.01f;
                offset.y += i * 0.01f;
                holes.Add(new List<Vector2> { offset + new Vector2(0f, 0f), offset + new Vector2(0f, 1f), offset + new Vector2(1f, 1f), offset + new Vector2(1f, 0f) });
            }
            Triangulator.TriangulatePoints(vertices, holes, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(78, indices.Length);
            Assert.AreEqual(12.0f, TestUtilities.CalculateTriangulatedArea(outVertices, indices), 0.01f);
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate an L shape
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateLShape()
        {
            var vertices = new List<Vector2> { new(0f, 0f), new(2f, 0f), new(2f, 2f), new(1f, 2f), new(1f, 1f), new(0f, 1f) };
            Triangulator.TriangulatePoints(vertices, null, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(12, indices.Length);
            Assert.AreEqual(3.0f, TestUtilities.CalculateTriangulatedArea(outVertices, indices));
        }

        /// <summary>
        /// Tests that the triangulator is able to triangulate a C shape
        /// </summary>
        [UnityTest]
        [Timeout(DefaultTimeoutMs)]
        public IEnumerator TriangulateCShape()
        {
            var vertices = new List<Vector2> { new(0f, 0f), new(2f, 0f), new(2f, 1f), new(1f, 1f), new(1f, 2f), new(2f, 2f), new(2f, 3f), new(0f, 3f) };
            Triangulator.TriangulatePoints(vertices, null, out var outVertices, out var indices);
            yield return null;
            Assert.AreEqual(18, indices.Length);
            Assert.AreEqual(5.0f, TestUtilities.CalculateTriangulatedArea(outVertices, indices));
        }
    }
}