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

namespace Slipstream.UnitTests
{
    public class PanelTests : UnitTestSharp.TestFixture
    {
        public void MiddleOfPanel()
        {
            var result = Panel.InducedVelocityFromSource(Vector.Zero, 2);

            CheckEqual(new Vector(0, Math.PI), result);
        }

        public void RightEdgeOfPanel()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(1, 0), 2);

            CheckEqual(new Vector(5, 0), result);
        }

        public void NearRightEdgeOfPanel_Inside()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(0.999999, 0), 2);

            CheckEqual(new Vector(5, Math.PI), result);
        }

        public void NearRightEdgeOfPanel_Outside()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(1.01, 0), 2);

            CheckEqual(new Vector(5, 0), result);
        }

        public void LeftEdgeOfPanel()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(-1, 0), 2);

            CheckEqual(new Vector(-5, 0), result);
        }

        public void NearLeftEdgeOfPanel_Inside()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(-0.999999, 0), 2);

            CheckEqual(new Vector(-5, Math.PI), result);
        }

        public void NearLeftEdgeOfPanel_Outside()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(-1.00001, 0), 2);

            CheckEqual(new Vector(-5, 0), result);
        }

        public void FarFarRightEdgeOfPanel()
        {
            var result = Panel.InducedVelocityFromSource(new Vector(100, 0), 2);

            CheckEqual(new Vector(Math.Log(101.0 * 101.0 / 99.0 / 99.0) / 2, 0), result);
        }

        public class PotentialFromSources : UnitTestSharp.TestFixture
        {
            public void Basic()
            {
                DenseVector x = new DenseVector(new Scalar[]
                {
                    0, 1, 2, 3,
                });

                DenseVector y = new DenseVector(new Scalar[]
                {
                    3, 2, 1, 0,
                });

                DenseVector potentials = new DenseVector(x.Length);

                Panel.InducedPotentialsFromSource(x, y, 1, ref potentials);

                var expected = new DenseVector(new Scalar[]
                {
                    Panel.InducedPotentialFromSource(new Vector(x[0], y[0]), 1),
                    Panel.InducedPotentialFromSource(new Vector(x[1], y[1]), 1),
                    Panel.InducedPotentialFromSource(new Vector(x[2], y[2]), 1),
                    Panel.InducedPotentialFromSource(new Vector(x[3], y[3]), 1),
                });

                CheckEqual(expected, potentials);
            }
        }
    }
}