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

namespace Slipstream.UnitTests
{
    public class BoundaryBodyTests : UnitTestSharp.TestFixture
    {
        public static SimplePolygon airfoil = new SimplePolygon(new Vector[]
        {
            new Vector(0, 0),
            new Vector(-10, 0),
            new Vector(-12, 1),
            new Vector(-11, 2),
            new Vector(-9, 3),
            new Vector(-8, 4),
        });

        public static SimplePolygon bluffRectangle = new SimplePolygon(new Vector[]
        {
            new Vector(-10, -1),
            new Vector(-10, 1),
            new Vector(10, 1),
            new Vector(10, -1),
        });

        public static SimplePolygon bluffSquare = new SimplePolygon(new Vector[]
        {
            new Vector(-5, -5),
            new Vector(-5, 5),
            new Vector(5, 5),
            new Vector(5, -5),
        });

        public static SimplePolygon equiTris = new SimplePolygon(new Vector[]
        {
            new Vector(0, 0),
            new Vector(1, 0),
            new Vector(0.5, Math.Sqrt(3)/2),
        });

        public void BluffSquareTest()
        {
            var perimeter = equiTris.CalculatePerimeter();

            BoundaryBody AirfoilBody = new BoundaryBody(equiTris, Vector.Zero, 0.0, 3);

            AirfoilBody.LinearVelocity = Vector.Zero;
            var freeStreeamVelocity = new Vector(100, 0);

            AirfoilBody.EnforceBoundaryConditions((x, i) => freeStreeamVelocity);

            var panelVelocities = AirfoilBody.PanelPositionWS.Select(x =>
                AirfoilBody.VelocityAtPoint(x)).ToList();
            var panelNormals = AirfoilBody.PanelNormalsWS.ToList();
            var panelTangents = AirfoilBody.PanelTangentsWS.ToList();

            Scalar circulation = 0;
            for (int i = 0; i < panelVelocities.Count; ++i)
            {
                var dot = (AirfoilBody.LinearVelocity + panelVelocities[i]).DotProduct(panelNormals[i]);
                CheckEqual(0, dot);
                circulation += panelVelocities[i].DotProduct(panelTangents[i]);
            }

            CheckEqual(0, circulation);
        }
    }
}