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

namespace Azimuth.UnitTests.DenseLinearAlgebra
{
    public class IVectorTests : UnitTestSharp.TestFixture
    {
        public class SubVector : UnitTestSharp.TestFixture
        {
            public void BadSubVector()
            {
                var dense = new DenseVector(new Scalar[] { 1, 2, 3 });

                CheckEqual(new DenseVector(0), dense.SubVector(3));
            }

            public void EmptyVector()
            {
                var dense = new DenseVector(new Scalar[] { });

                CheckEqual(new DenseVector(0), dense.SubVector(0));
            }

            public void RoundTrip()
            {
                var dense = new DenseVector(new Scalar[] { 1, 2, 3 });

                CheckEqual(dense, dense.SubVector(0));
            }

            public void Works()
            {
                var dense = new DenseVector(new Scalar[] { 1, 2, 3 });

                CheckEqual(new DenseVector(new Scalar[] { 3 }), dense.SubVector(2));
            }

            public void BadIndex()
            {
                var dense = new DenseVector(new Scalar[] { 1, 2, 3 });

                CheckThrow(typeof(Exception));
                dense.SubVector(-1);
            }
        }

        public class PostMatrixMultiply : UnitTestSharp.TestFixture
        {
            public void NonSymmetricOrthogonal()
            {
                var matrix = new SquareMatrix(new Scalar[,] { 
                    { 0, -1, },
                    { 1,  0, },
                });

                var vector = new DenseVector(new Scalar[] { 3, 4 });
                var expected  = new DenseVector(new Scalar[] { 4, -3 });

                CheckEqual(expected, vector.PostMatrixMultiplyBy(matrix));
            }

            public void NonSquare_Fat()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0, -1, 1, },
                    { 1,  0, 1, },
                });

                var vector = new DenseVector(new Scalar[] { 3, 4 });
                var expected = new DenseVector(new Scalar[] { 4, -3, 7 });

                CheckEqual(expected, vector.PostMatrixMultiplyBy(matrix));
            }

            public void NonSquare_Tall()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0 },
                    { 1 },
                });

                var vector = new DenseVector(new Scalar[] { 3, 4 });
                var expected = new DenseVector(new Scalar[] { 4 });

                CheckEqual(expected, vector.PostMatrixMultiplyBy(matrix));
            }

            public void DimsDontMatch()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0, -1, 1, },
                    { 1,  0, 1, },
                });

                var vector = new DenseVector(new Scalar[] { 3 });
                
                CheckThrow(typeof(Exception));                
                vector.PostMatrixMultiplyBy(matrix);
            }
        }

        public class PreMatrixMultiply : UnitTestSharp.TestFixture
        {
            public void NonSymmetricOrthogonal()
            {
                var matrix = new SquareMatrix(new Scalar[,] { 
                    { 0, -1, },
                    { 1,  0, },
                });

                var vector = new DenseVector(new Scalar[] { 3, 4 });
                var expected = new DenseVector(new Scalar[] { -4, 3 });

                CheckEqual(expected, vector.PreMatrixMultiplyBy(matrix));
            }

            public void NonSquare_Fat()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0, -1, 1, },
                    { 1,  0, 1, },
                });

                var vector = new DenseVector(new Scalar[] { 4, -3, 7 });
                var expected = new DenseVector(new Scalar[] { 10, 11 });

                CheckEqual(expected, vector.PreMatrixMultiplyBy(matrix));
            }

            public void NonSquare_Tall()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0, 1 },
                });

                var vector = new DenseVector(new Scalar[] { 3, 4 });
                var expected = new DenseVector(new Scalar[] { 4 });

                CheckEqual(expected, vector.PreMatrixMultiplyBy(matrix));
            }

            public void DimsDontMatch()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 0, -1, 1, },
                    { 1,  0, 1, },
                });

                var vector = new DenseVector(new Scalar[] { 3 });

                CheckThrow(typeof(Exception));
                vector.PreMatrixMultiplyBy(matrix);
            }

            public void AggressiveTesting()
            {
                var matrix = new RectangularMatrix(new Scalar[,] { 
                    { 1, 2, },
                    { 3, 4, },
                });

                var vector = new DenseVector(new Scalar[] { 5, 6, });
                var expected = new DenseVector(new Scalar[] { 17, 39 });

                vector = vector.PreMatrixMultiplyBy(matrix);

                CheckEqual(expected, vector);
            }
        }

        public class CountTests : UnitTestSharp.TestFixture
        {
            DenseVector dense = new DenseVector(new Scalar[] { -1, 1, -1, 0, 1, 2, 3 });
            public void Basic()
            {
                CheckEqual(7, dense.Count());
            }

            public void Negative()
            {
                CheckEqual(2, dense.Count(x => x < 0));
            }

            public void Positive()
            {
                CheckEqual(5, dense.Count(x => x.Sign == 1));
            }
        }

        public class AllTests : UnitTestSharp.TestFixture
        {
            DenseVector dense = new DenseVector(new Scalar[] { -1, 1, -1, 0, 1, 2, 3 });
            public void False()
            {
                CheckFalse(dense.All(x => x.Sign == 1));
            }

            public void True()
            {
                Check(dense.All(x => x < 50));
                Check(dense.All(x => x > -50));
            }
        }

        public class AnyTests : UnitTestSharp.TestFixture
        {
            DenseVector dense = new DenseVector(new Scalar[] { -1, 1, -1, 0, 1, 2, 3 });
            
            public void False()
            {
                CheckFalse(dense.Any(x => x.Sign == 0));
            }

            public void True()
            {
                Check(dense.Any(x => x.Sign == 1));
                Check(dense.Any(x => x.Sign == -1));
            }
        }
    }
}