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

namespace Azimuth.UnitTests.SparseLinearAlgebra
{
    public class BandedUpperTriangularTests : UnitTestSharp.TestFixture
    {
        public class Ctor : UnitTestSharp.TestFixture
        {
            public void FromScalarArray()
            {
                var elements = new Scalar[,]
                {
                    { 1, 2, 0, 0, },
                    { 0, 3, 4, 0, },
                    { 0, 0, 5, 6, },
                    { 0, 0, 0, 7, },
                };

                var band = new BandedUpperTriangular(elements);
                var mat = new SquareMatrix(elements);

                CheckEqual(4, band.Size);
                CheckEqual(2, band.Bandwidth);
                CheckEqual(mat, band);
            }

            public void FromSquareMatrix()
            {
                var elements = new Scalar[,]
                {
                    { 1, 2, 0, 0, },
                    { 0, 3, 4, 0, },
                    { 0, 0, 5, 6, },
                    { 0, 0, 0, 7, },
                };

                var mat = new SquareMatrix(elements);
                var band = new BandedUpperTriangular(mat);                

                CheckEqual(4, band.Size);
                CheckEqual(2, band.Bandwidth);
                CheckEqual(mat, band);
            }

            public void OffBand()
            {
                CheckThrow(typeof(Exception));
                var band = new BandedUpperTriangular(new Scalar[,]
                {
                    { 1, 2, 0, 0, },
                    { 0, 3, 4, 0, },
                    { 0, 0, 5, 6, },
                    { 1, 0, 0, 7, },
                });
            }

            public void UnfortunateBandwidth()
            {
                var elements = new Scalar[,]
                {
                    { 1, 2, 0, 1, },
                    { 0, 3, 4, 0, },
                    { 0, 0, 5, 6, },
                    { 0, 0, 0, 7, },
                };

                var mat = new SquareMatrix(elements);
                var band = new BandedUpperTriangular(mat);

                CheckEqual(4, band.Size);
                CheckEqual(4, band.Bandwidth);
                CheckEqual(mat, band);
            }
        }

        public class Passthrough : UnitTestSharp.TestFixture
        {
            public void Basic()
            {
                var band = new BandedUpperTriangular(new Scalar[,]
                {
                    { 1, 2, 0, 0, },
                    { 0, 3, 4, 0, },
                    { 0, 0, 5, 6, },
                    { 0, 0, 0, 7, },
                });

                var gauss = new GaussTransform
                {
                    Index = 1,
                    Weight = 2,
                };

                band.Passthrough(ref gauss);

                var expectedBand = new BandedUpperTriangular(new Scalar[,]
                {
                    { 1, 2, 0, 0, },
                    { 0, 11, 4, 0, },
                    { 0, 0, 15.0/11.0, 6, },
                    { 0, 0, 0, 7, },
                });

                var expectedGauss = new GaussTransform
                {
                    Index = 1,
                    Weight = -10.0/11.0,
                };

                CheckEqual(expectedGauss, gauss);
                CheckEqual(expectedBand, band);
            }
        }
    }
}