defineSuite([
        'Core/EllipsoidTangentPlane',
        'Core/Cartesian2',
        'Core/Cartesian3',
        'Core/Ellipsoid'
    ], function(
        EllipsoidTangentPlane,
        Cartesian2,
        Cartesian3,
        Ellipsoid) {
    'use strict';

    it('constructor defaults to WGS84', function() {
        var origin = new Cartesian3(Ellipsoid.WGS84.radii.x, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin);
        expect(tangentPlane.ellipsoid).toBe(Ellipsoid.WGS84);
        expect(tangentPlane.origin).toEqual(origin);
    });

    it('constructor sets expected values', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(tangentPlane.ellipsoid).toBe(Ellipsoid.UNIT_SPHERE);
        expect(tangentPlane.origin).toEqual(Cartesian3.UNIT_X);
    });

    it('fromPoints sets expected values', function() {
            var points = [new Cartesian3(2.0, 0.0, 0.0), new Cartesian3(0.0, 0.0, 0.0)];
        var tangentPlane = EllipsoidTangentPlane.fromPoints(points, Ellipsoid.UNIT_SPHERE);
        expect(tangentPlane.ellipsoid).toBe(Ellipsoid.UNIT_SPHERE);
        expect(tangentPlane.origin).toEqual(Cartesian3.UNIT_X);
    });

    it('projectPointOntoPlane returns undefined for unsolvable projections', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);
        var positions = new Cartesian3(0.0, 0.0, 1.0);
        var returnedResult = tangentPlane.projectPointOntoPlane(positions);
        expect(returnedResult).toBeUndefined();
    });

    it('projectPointOntoPlane works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = new Cartesian3(1.0, 0.0, 1.0);
        var expectedResult = new Cartesian2(0.0, 1.0);
        var returnedResult = tangentPlane.projectPointOntoPlane(positions);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointOntoPlane works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = new Cartesian3(1.0, 0.0, 1.0);
        var expectedResult = new Cartesian2(0.0, 1.0);
        var result = new Cartesian2();
        var returnedResult = tangentPlane.projectPointOntoPlane(positions, result);
        expect(result).toBe(returnedResult);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointsOntoPlane works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(1.0, 0.0, 1.0), new Cartesian3(1.0, 0.0, 0.0), new Cartesian3(1.0, 1.0, 0.0)];
        var expectedResults = [new Cartesian2(0.0, 1.0), new Cartesian2(0.0, 0.0), new Cartesian2(1.0, 0.0)];
        var returnedResults = tangentPlane.projectPointsOntoPlane(positions);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointsOntoPlane works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(1.0, 0.0, 1.0), new Cartesian3(1.0, 0.0, 0.0), new Cartesian3(1.0, 1.0, 0.0)];
        var expectedResults = [new Cartesian2(0.0, 1.0), new Cartesian2(0.0, 0.0), new Cartesian2(1.0, 0.0)];

        var index0 = new Cartesian2();
        var result = [index0];
        var returnedResults = tangentPlane.projectPointsOntoPlane(positions, result);
        expect(result).toBe(returnedResults);
        expect(result[0]).toBe(index0);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointsOntoPlane works when some points cannot be projected', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(1.0, 0.0, 1.0), new Cartesian3(1.0, 0.0, 0.0), new Cartesian3(0.0, 0.0, 1.0), new Cartesian3(1.0, 1.0, 0.0), new Cartesian3(0.0, 1.0, 0.0)];
        var expectedResults = [new Cartesian2(0.0, 1.0), new Cartesian2(0.0, 0.0), new Cartesian2(1.0, 0.0)];
        var returnedResults = tangentPlane.projectPointsOntoPlane(positions);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointOntoEllipsoid works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var position = new Cartesian3(2.0, 2.0, 0.0);
        var expectedResult = new Cartesian3(1.0/3.0, 2.0/3.0,  2.0/3.0);
        var returnedResult = tangentPlane.projectPointOntoEllipsoid(position);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointOntoEllipsoid works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var position = new Cartesian3(2.0, -2.0, 0.0);
        var expectedResult = new Cartesian3(1.0/3.0, 2.0/3.0, -2.0/3.0);
        var result = new Cartesian3();
        var returnedResult = tangentPlane.projectPointOntoEllipsoid(position, result);
        expect(result).toBe(returnedResult);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointsOntoEllipsoid works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(2.0, -2.0, 0.0), new Cartesian3(2.0, 2.0, 0.0)];
        var expectedResults = [new Cartesian3(1.0/3.0, 2.0/3.0, -2.0/3.0), new Cartesian3(1.0/3.0, 2.0/3.0,  2.0/3.0)];
        var returnedResults = tangentPlane.projectPointsOntoEllipsoid(positions);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointsOntoEllipsoid works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(2.0, -2.0, 0.0), new Cartesian3(2.0, 2.0, 0.0)];
        var expectedResults = [new Cartesian3(1.0/3.0, 2.0/3.0, -2.0/3.0), new Cartesian3(1.0/3.0, 2.0/3.0,  2.0/3.0)];
        var index0 = new Cartesian3();
        var result = [index0];
        var returnedResults = tangentPlane.projectPointsOntoEllipsoid(positions, result);
        expect(result).toBe(returnedResults);
        expect(result[0]).toBe(index0);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointToNearestOnPlane works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = new Cartesian3(1.0, 0.0, 1.0);
        var expectedResult = new Cartesian2(0.0, 1.0);
        var returnedResult = tangentPlane.projectPointToNearestOnPlane(positions);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointToNearestOnPlane works projecting from various distances', function () {
        var ellipsoid = Ellipsoid.ZERO;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        expect(tangentPlane.projectPointToNearestOnPlane(new Cartesian3(2.0, 0.0, 0.0))).toEqual(new Cartesian2(0.0, 0.0));
        expect(tangentPlane.projectPointToNearestOnPlane(new Cartesian3(1.0, 0.0, 0.0))).toEqual(new Cartesian2(0.0, 0.0));
        expect(tangentPlane.projectPointToNearestOnPlane(new Cartesian3(0.0, 0.0, 0.0))).toEqual(new Cartesian2(0.0, 0.0));
        expect(tangentPlane.projectPointToNearestOnPlane(new Cartesian3(-1.0, 0.0, 0.0))).toEqual(new Cartesian2(0.0, 0.0));
    });

    it('projectPointToNearestOnPlane works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = new Cartesian3(1.0, 0.0, 1.0);
        var expectedResult = new Cartesian2(0.0, 1.0);
        var result = new Cartesian2();
        var returnedResult = tangentPlane.projectPointToNearestOnPlane(positions, result);
        expect(result).toBe(returnedResult);
        expect(returnedResult).toEqual(expectedResult);
    });

    it('projectPointsToNearestOnPlane works without a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(1.0, 0.0, 1.0), new Cartesian3(1.0, 0.0, 0.0), new Cartesian3(1.0, 1.0, 0.0)];
        var expectedResults = [new Cartesian2(0.0, 1.0), new Cartesian2(0.0, 0.0), new Cartesian2(1.0, 0.0)];
        var returnedResults = tangentPlane.projectPointsToNearestOnPlane(positions);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('projectPointsToNearestOnPlane works with a result parameter', function () {
        var ellipsoid = Ellipsoid.UNIT_SPHERE;
        var origin = new Cartesian3(1.0, 0.0, 0.0);
        var tangentPlane = new EllipsoidTangentPlane(origin, ellipsoid);

        var positions = [new Cartesian3(1.0, 0.0, 1.0), new Cartesian3(1.0, 0.0, 0.0), new Cartesian3(1.0, 1.0, 0.0)];
        var expectedResults = [new Cartesian2(0.0, 1.0), new Cartesian2(0.0, 0.0), new Cartesian2(1.0, 0.0)];

        var index0 = new Cartesian2();
        var result = [index0];
        var returnedResults = tangentPlane.projectPointsToNearestOnPlane(positions, result);
        expect(result).toBe(returnedResults);
        expect(result[0]).toBe(index0);
        expect(returnedResults).toEqual(expectedResults);
    });

    it('constructor throws without origin', function() {
        expect(function() {
            return new EllipsoidTangentPlane(undefined, Ellipsoid.WGS84);
        }).toThrowDeveloperError();
    });

    it('constructor throws if origin is at the center of the ellipsoid', function() {
        expect(function() {
            return new EllipsoidTangentPlane(Cartesian3.ZERO, Ellipsoid.WGS84);
        }).toThrowDeveloperError();
    });

    it('fromPoints throws without cartesians', function() {
        expect(function() {
            return EllipsoidTangentPlane.fromPoints(undefined, Ellipsoid.WGS84);
        }).toThrowDeveloperError();
    });

    it('projectPointOntoPlane throws without cartesian', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(function() {
            return tangentPlane.projectPointOntoPlane(undefined);
        }).toThrowDeveloperError();
    });

    it('projectPointsOntoPlane throws without cartesians', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(function() {
            return tangentPlane.projectPointsOntoPlane(undefined);
        }).toThrowDeveloperError();
    });

    it('projectPointToNearestOnPlane throws without cartesian', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(function() {
            return tangentPlane.projectPointToNearestOnPlane(undefined);
        }).toThrowDeveloperError();
    });

    it('projectPointsToNearestOnPlane throws without cartesians', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(function() {
            return tangentPlane.projectPointsToNearestOnPlane(undefined);
        }).toThrowDeveloperError();
    });

    it('projectPointsOntoEllipsoid throws without cartesians', function() {
        var tangentPlane = new EllipsoidTangentPlane(Cartesian3.UNIT_X, Ellipsoid.UNIT_SPHERE);
        expect(function() {
            return tangentPlane.projectPointsOntoEllipsoid(undefined);
        }).toThrowDeveloperError();
    });

    it('projectPointsOntoEllipsoid works with an arbitrary ellipsoid using fromPoints', function () {
        var points = Cartesian3.fromDegreesArray([
            -72.0, 40.0,
            -68.0, 35.0,
            -75.0, 30.0,
            -70.0, 30.0,
            -68.0, 40.0
        ]);

        var tangentPlane = EllipsoidTangentPlane.fromPoints(points, Ellipsoid.WGS84);
        var points2D = tangentPlane.projectPointsOntoPlane(points);
        var positionsBack = tangentPlane.projectPointsOntoEllipsoid(points2D);

        expect(positionsBack[0].x).toBeCloseTo(points[0].x);
        expect(positionsBack[0].y).toBeCloseTo(points[0].y);
        expect(positionsBack[0].z).toBeCloseTo(points[0].z);
    });
});