using Azimuth.Polynomials;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using UnitTestSharp;

namespace Azimuth.UnitTests.Polynomials
{
    public class ComplexRationalTests : TestFixture
    {
        public void EmbeddedReal()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                5, -6, 1,
                1, 1
            });

            var rational = new ComplexRational(coefficients, numeratorTerms: 3);
            CheckEqual(0, rational.Evaluate(1));
            CheckEqual(-1, rational.Evaluate(2));
            CheckEqual(-1, rational.Evaluate(3));
            CheckEqual(-3.0/5, rational.Evaluate(4));
        }

        public void FullyComplexEquation()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
                (7, -8), (-9, 10),
            });

            var rational = new ComplexRational(coefficients, numeratorTerms: 3);
            CheckEqual((13.0/4, -9.0/4), rational.Evaluate(1));
            CheckEqual((391.0 / 265, -248.0/265), rational.Evaluate(2));
            CheckEqual((665.0 / 442, -242.0/221), rational.Evaluate(3));
            CheckEqual((3089.0 / 1865, -2508.0/1865), rational.Evaluate(4));

            CheckEqual((119.0/298, 21.0/298), rational.Evaluate((0, 1)));
            CheckEqual((61.0/65, 18.0/65), rational.Evaluate((0, 2)));
            CheckEqual((2341.0/1754, 937.0/1754), rational.Evaluate((0, 3)));
            CheckEqual((463.0 / 275, 216.0/275), rational.Evaluate((0, 4)));
        }

        public void EvaluateAtZero()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
                (7, -8), (-9, 10),
            });

            var rational = new ComplexRational(coefficients, numeratorTerms: 3);
            CheckEqual((-11.0/113, 52.0/113), rational.EvaluateAtZero());
        }

        public void EvaluateAtOne()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
                (7, -8), (-9, 10),
            });

            var rational = new ComplexRational(coefficients, numeratorTerms: 3);
            CheckEqual((13.0/4, -9.0/4), rational.EvaluateAtOne());
        }

        public void ZeroNumeratorTerms()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (7, -8), (-9, 10),
            });

            var rational = new ComplexRational(coefficients, numeratorTerms: 0);
            CheckEqual(0, rational.Evaluate(1));
        }

        public void ZeroDenominatorTerms()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
            });

            CheckThrow(typeof(ArgumentException));
            new ComplexRational(coefficients, numeratorTerms: 3);
        }

        public void NegativeNumeratorTerms()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
            });

            CheckThrow(typeof(ArgumentException));
            new ComplexRational(coefficients, numeratorTerms: -1);
        }

        public void TooManyNumeratorTerms()
        {
            var coefficients = new ComplexDenseVector(new Complex[]
            {
                (3, 4), (-6, 2), (1, 5),
            });

            CheckThrow(typeof(ArgumentException));
            new ComplexRational(coefficients, numeratorTerms: 4);
        }
    }
}