using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Azimuth.DenseLinearAlgebra;

namespace Azimuth.UnitTests.DenseLinearAlgebra
{
    public class DenseVectorPoolTests : UnitTestSharp.TestFixture
    {
        public class Log2Tests : UnitTestSharp.TestFixture
        {
            public void _0()
            {
                var log2 = DenseVectorPool.Base2.Log2(0);

                CheckEqual(0, log2);
            }

            public void _1()
            {
                var log2 = DenseVectorPool.Base2.Log2(1);

                CheckEqual(1, log2);
            }

            public void _2()
            {
                var log2 = DenseVectorPool.Base2.Log2(2);

                CheckEqual(1, log2);
            }

            public void _3()
            {
                var log2 = DenseVectorPool.Base2.Log2(3);

                CheckEqual(2, log2);
            }

            public void _4()
            {
                var log2 = DenseVectorPool.Base2.Log2(4);

                CheckEqual(2, log2);
            }

            public void _5()
            {
                var log2 = DenseVectorPool.Base2.Log2(5);

                CheckEqual(3, log2);
            }

            public void _2Pow30()
            {
                var log2 = DenseVectorPool.Base2.Log2(0x1 << 30);

                CheckEqual(30, log2);
            }

            public void _2Pow30_Minus1()
            {
                var log2 = DenseVectorPool.Base2.Log2((0x1 << 30) - 1);

                CheckEqual(30, log2);
            }

            public void _2Pow30_Plus1()
            {
                var log2 = DenseVectorPool.Base2.Log2((0x1 << 30) + 1);

                CheckEqual(31, log2);
            }

            public void _2Pow31_Plus1()
            {
                uint x = 0x1;
                x <<= 31;
                var log2 = DenseVectorPool.Base2.Log2(x + 1);

                CheckEqual(32, log2);
            }
        }

        public void GetDenseVector_Pow2_CreateNew()
        {
            var oldScalars = DenseVectorPool.AggregateScalarsInPool;
            {
                var vector = DenseVectorPool.GetDenseVector_FromLog2(5);

                CheckEqual(32, vector.Length);
            }
            CheckEqual(oldScalars, DenseVectorPool.AggregateScalarsInPool);
        }

        public void GetDenseVector_Pow2_FromPool()
        {
            var oldScalars = DenseVectorPool.AggregateScalarsInPool;
            {
                DenseVectorPool.ReturnDenseVector(new DenseVector(1024), 10);
                CheckEqual(oldScalars + 1024, DenseVectorPool.AggregateScalarsInPool);
                var vector = DenseVectorPool.GetDenseVector_FromLog2(10);

                CheckEqual(1024, vector.Length);
            }
            CheckEqual(oldScalars, DenseVectorPool.AggregateScalarsInPool);
        }

        public void GetDenseVector_CreateNew()
        {
            var oldScalars = DenseVectorPool.AggregateScalarsInPool;
            {
                var vector = DenseVectorPool.GetDenseVector(1000);

                CheckEqual(1000, vector.Length);
            }
            CheckEqual(oldScalars, DenseVectorPool.AggregateScalarsInPool);
        }

        public void GetDenseVector_FromPool()
        {
            var oldScalars = DenseVectorPool.AggregateScalarsInPool;
            {
                var vec = new DenseVector(1024);
                vec.SetLength(999);
                DenseVectorPool.ReturnDenseVector(vec);
                CheckEqual(oldScalars + 1024, DenseVectorPool.AggregateScalarsInPool);
                var vector = DenseVectorPool.GetDenseVector(1000);

                CheckEqual(1000, vector.Length);
            }
            CheckEqual(oldScalars, DenseVectorPool.AggregateScalarsInPool);
        }
    }
}