using System;
using System.Linq;
using System.Numerics;

using NUnit.Framework;

namespace SharpGLTF.Memory
{
    [TestFixture]
    [Category("Core Memory")]
    public class MemoryArrayTests
    {
        [Test]
        public void TestFloatingArrayDecoding()
        {
            Assert.That(_CreateFloatingAccessor(new Byte[] { 17 }, Schema2.EncodingType.UNSIGNED_BYTE, false)[0], Is.EqualTo(17));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 17, 0 }, Schema2.EncodingType.UNSIGNED_SHORT, false)[0], Is.EqualTo(17));            

            Assert.That(_CreateFloatingAccessor(new Byte[] { 17 }, Schema2.EncodingType.BYTE, false)[0], Is.EqualTo(17));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 17, 0 }, Schema2.EncodingType.SHORT, false)[0], Is.EqualTo(17));

            Assert.That(_CreateFloatingAccessor(new Byte[] { 255 }, Schema2.EncodingType.UNSIGNED_BYTE, true)[0], Is.EqualTo(1));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 127 }, Schema2.EncodingType.BYTE, true)[0], Is.EqualTo(1));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 128 }, Schema2.EncodingType.BYTE, true)[0], Is.EqualTo(-1));

            Assert.That(_CreateFloatingAccessor(new Byte[] { 255, 255 }, Schema2.EncodingType.UNSIGNED_SHORT, true)[0], Is.EqualTo(1));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 255, 127 }, Schema2.EncodingType.SHORT, true)[0], Is.EqualTo(1));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 0,  128 }, Schema2.EncodingType.SHORT, true)[0], Is.EqualTo(-1));

            Assert.That(_CreateFloatingAccessor(new Byte[] { 17, 0, 0, 0 }, Schema2.EncodingType.UNSIGNED_INT, false)[0], Is.EqualTo(17));
            Assert.That(_CreateFloatingAccessor(new Byte[] { 0,0, 0x80, 0x3f }, Schema2.EncodingType.FLOAT, false)[0], Is.EqualTo(1));
        }

        private static FloatingAccessor _CreateFloatingAccessor(byte[] data, Schema2.EncodingType encoding, bool normalized)
        {
            return new FloatingAccessor(new ArraySegment<byte>(data), 0, int.MaxValue, 0, 1, encoding, normalized);
        }        

        [Test]
        public void TestFloatingArrayEncoding1()
        {
            var v1 = new Vector4(0.1f, 0.2f, 0.6f, 0.8f);
            var v2 = new Vector4(1, 2, 3, 4);

            var bytes = new Byte[256];

            var v4n = new Vector4Array(bytes, 0, Schema2.EncodingType.UNSIGNED_BYTE, true);
            v4n[1] = v1;
            NumericsAssert.AreEqual(v4n[1], v1, 0.1f);

            var v4u = new Vector4Array(bytes, 0, Schema2.EncodingType.UNSIGNED_BYTE, false);
            v4u[1] = v2;
            NumericsAssert.AreEqual(v4u[1], v2);
        }

        [Test]
        public void TestFloatingArrayEncoding2()
        {
            var v1 = new Vector4(0.1f, 0.2f, 0.6f, 0.8f);
            var v2 = new Vector4(1, 2, 3, 4);

            var bytes = new Byte[256];

            var v4n = new Vector4Array(bytes, 0, 5, 8, Schema2.EncodingType.UNSIGNED_BYTE, true);
            var v4u = new Vector4Array(bytes, 4, 5, 8, Schema2.EncodingType.UNSIGNED_BYTE, false);

            v4n[1] = v1;
            NumericsAssert.AreEqual(v4n[1], v1, 0.1f);

            
            v4u[1] = v2;
            NumericsAssert.AreEqual(v4u[1], v2);
        }

        [Test]
        public void TestLinqAccess()
        {
            var buffer = new Byte[] { 1, 52, 43, 6, 23, 234 };

            var accessor = new Vector2Array(buffer, 0, Schema2.EncodingType.BYTE, true);

            var result = accessor.ToArray();

            Assert.That(result, Has.Length.EqualTo(3));
        }
    }
}