#nullable enable

using System.Diagnostics.CodeAnalysis;
using NUnit.Framework;
using UnityEngine;
using Object = UnityEngine.Object;

namespace X10D.Unity.Tests
{
    public class GameObjectTests
    {
        [Test]
        public void GetComponentsInChildrenOnly_ShouldIgnoreParent()
        {
            var parent = new GameObject();
            parent.AddComponent<Rigidbody>();

            var child = new GameObject();
            child.transform.SetParent(parent.transform);
            child.AddComponent<Rigidbody>();

            Rigidbody[] components = parent.GetComponentsInChildrenOnly<Rigidbody>();
            Assert.That(components, Has.Length.EqualTo(1));
            Assert.That(child, Is.EqualTo(components[0].gameObject));

            Object.Destroy(parent);
            Object.Destroy(child);
        }

        [Test]
        [SuppressMessage("ReSharper", "Unity.InefficientPropertyAccess", Justification = "False positive.")]
        public void LookAt_ShouldRotateSameAsTransform()
        {
            var first = new GameObject {transform = {position = Vector3.zero, rotation = Quaternion.identity}};
            var second = new GameObject {transform = {position = Vector3.right, rotation = Quaternion.identity}};
            Transform firstTransform = first.transform;
            Transform secondTransform = second.transform;

            Assert.That(firstTransform.rotation, Is.EqualTo(Quaternion.identity));
            Assert.That(secondTransform.rotation, Is.EqualTo(Quaternion.identity));

            firstTransform.LookAt(secondTransform);
            Quaternion expected = firstTransform.rotation;

            firstTransform.rotation = Quaternion.identity;
            Assert.That(firstTransform.rotation, Is.EqualTo(Quaternion.identity));

            first.LookAt(second);
            Assert.That(firstTransform.rotation, Is.EqualTo(expected));

            firstTransform.rotation = Quaternion.identity;
            Assert.That(firstTransform.rotation, Is.EqualTo(Quaternion.identity));

            first.LookAt(second.transform);
            Assert.That(firstTransform.rotation, Is.EqualTo(expected));

            firstTransform.rotation = Quaternion.identity;
            Assert.That(firstTransform.rotation, Is.EqualTo(Quaternion.identity));

            first.LookAt(Vector3.right);
            Assert.That(firstTransform.rotation, Is.EqualTo(expected));

            Object.Destroy(first);
            Object.Destroy(second);
        }

        [Test]
        public void SetLayerRecursively_ShouldSetLayerRecursively()
        {
            var parent = new GameObject();
            var child = new GameObject();
            var grandChild = new GameObject();

            child.transform.SetParent(parent.transform);
            grandChild.transform.SetParent(child.transform);

            int layer = LayerMask.NameToLayer("UI");
            Assert.AreNotEqual(layer, parent.layer);
            Assert.AreNotEqual(layer, child.layer);
            Assert.AreNotEqual(layer, grandChild.layer);

            parent.SetLayerRecursively(layer);

            Assert.That(parent.layer, Is.EqualTo(layer));
            Assert.That(child.layer, Is.EqualTo(layer));
            Assert.That(grandChild.layer, Is.EqualTo(layer));

            Object.Destroy(parent);
            Object.Destroy(child);
            Object.Destroy(grandChild);
        }

        [Test]
        [SuppressMessage("ReSharper", "Unity.InefficientPropertyAccess", Justification = "False positive.")]
        public void SetParent_ShouldSetParent()
        {
            var first = new GameObject {transform = {position = Vector3.zero, rotation = Quaternion.identity}};
            var second = new GameObject {transform = {position = Vector3.right, rotation = Quaternion.identity}};

            Assert.That(first.transform.parent, Is.EqualTo(null));
            Assert.That(second.transform.parent, Is.EqualTo(null));

            first.SetParent(second);
            Assert.That(first.transform.parent, Is.EqualTo(second.transform));

            first.transform.SetParent(null!);
            Assert.That(first.transform.parent, Is.EqualTo(null));

            second.SetParent(first);
            Assert.That(second.transform.parent, Is.EqualTo(first.transform));

            Object.Destroy(first);
            Object.Destroy(second);
        }
    }
}