/*!
 * 01_tuples.cpp
 *
 * Copyright (c) 2015-2024, NADAL Jean-Baptiste. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA
 *
 * @Author:  NADAL Jean-Baptiste
 * @Date: 29/01/2024
 *
 */

/*---------------------------------------------------------------------------*/

#include <cmath>

#include <catch2/catch_test_macros.hpp>

#include "core/tuple.h"

using namespace Raytracer;

/* ------------------------------------------------------------------------- */

SCENARIO("A tuple with w=1.0 is a point", "[features/tuples.feature]")
{
    GIVEN("A tuple with w=1.0 is a point")
    {
        Tuple a(4.3, -4.2, 3.1, 1.0);
        THEN("a.x = 4.3")
        {
            REQUIRE(a.x() == 4.3);
        }
        AND_THEN("a.y = -4.2")
        {
            REQUIRE(a.y() == -4.2);
        }
        AND_THEN("a.z = 3.1")
        {
            REQUIRE(a.z() == 3.1);
        }
        AND_THEN("a.w = 1.0")
        {
            REQUIRE(a.w() == 1.0);
        }
        AND_THEN("a is a point")
        {
            REQUIRE(a.is_point() == true);
        }
        AND_THEN("a is not a vector")
        {
            REQUIRE(a.is_vector() == false);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("A tuple with w=0 is a vector", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(4.3, -4.2, 3.1, 0.0)")
    {
        Tuple a(4.3, -4.2, 3.1, 0.0);
        THEN("a.x = 4.3")
        {
            REQUIRE(a.x() == 4.3);
        }
        AND_THEN("a.y = -4.2")
        {
            REQUIRE(a.y() == -4.2);
        }
        AND_THEN("a.z = 3.1")
        {
            REQUIRE(a.z() == 3.1);
        }
        AND_THEN("a.w = 0.0")
        {
            REQUIRE(a.w() == 0.0);
        }
        AND_THEN("a is not a point")
        {
            REQUIRE(a.is_point() == false);
        }
        AND_THEN("a is a vector")
        {
            REQUIRE(a.is_vector() == true);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Access of data with []", "[features/tuples.feature]")
{
    GIVEN(" a <- tuple(4.3, -4.2, 3.1, 0.0)")
    {
        Tuple a(4.3, -4.2, 3.1, 0.0);
        THEN("a[0] = 4.3")
        {
            REQUIRE(a[0] == 4.3);
        }
        AND_THEN("a[1] = -4.2")
        {
            REQUIRE(a[1] == -4.2);
        }
        AND_THEN("a[2] = 3.1")
        {
            REQUIRE(a[2] == 3.1);
        }
        AND_THEN("a[3] = 0.0")
        {
            REQUIRE(a[3] == 0.0);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("A constructor with std::vector", "[features/tuples.feature]")
{
    GIVEN(" a <- tuple with {4.3, -4.2, 3.1, 0.0}")
    {
        std::vector<double> v = {4.3, -4.2, 3.1, 0.0};
        Tuple a(v);

        THEN("a[0] = 4.3")
        {
            REQUIRE(a[0] == 4.3);
        }
        AND_THEN("a[1] = -4.2")
        {
            REQUIRE(a[1] == -4.2);
        }
        AND_THEN("a[2] = 3.1")
        {
            REQUIRE(a[2] == 3.1);
        }
        AND_THEN("a[3] = 0.0")
        {
            REQUIRE(a[3] == 0.0);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("A test copy constructor", "[features/tuples.feature]")
{
    GIVEN(" a <- tuple(4.3, -4.2, 3.1, 0.0)")
    {
        Tuple a(4.3, -4.2, 3.1, 0.0);
        AND_GIVEN(" b <- tuple")
        {
            Tuple b;
            WHEN("b = a")
            {
                b = a;
                THEN("b[0] = 4.3")
                {
                    REQUIRE(b[0] == 4.3);
                }
                AND_THEN("b[1] = -4.2")
                {
                    REQUIRE(b[1] == -4.2);
                }
                AND_THEN("b[2] = 3.1")
                {
                    REQUIRE(b[2] == 3.1);
                }
                AND_THEN("b[3] = 0.0")
                {
                    REQUIRE(b[3] == 0.0);
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Tuple could be copy", "[features/tuples.feature]")
{
    GIVEN("p <-point(4, -4, 3)")
    {
        Tuple p = Tuple::Point(4, -4, 3);
        Tuple n;
        WHEN("n <- p")
        {
            n = p;
            THEN(" n = p")
            {
                REQUIRE(n == p);
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Point() creates tuples with w=1", "[features/tuples.feature]")
{
    GIVEN("p <-point(4, -4, 3)")
    {
        Tuple p = Tuple::Point(4, -4, 3);
        THEN("p = tuple(4,-4, 3, 1)")
        {
            REQUIRE(p == Tuple(4, -4, 3, 1));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Vector() creates tuples with w=0", "[features/tuples.feature]")
{
    GIVEN("v <-vector(4, -4, 3)")
    {
        Tuple v = Tuple::Vector(4, -4, 3);
        THEN("v = tuple(4,-4, 3, 1)")
        {
            REQUIRE(v == Tuple(4, -4, 3, 0));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Adding two tuples", "[features/tuples.feature]")
{
    GIVEN("a1 <-tuple(3, -2, 5, 1)")
    {
        Tuple a1(3, -2, 5, 1);
        AND_GIVEN("a2 <- tuple(-2, 3, 1, 0)")
        {
            Tuple a2(-2, 3, 1, 0);
            THEN("a1 + a2 = tuple(1, 1, 6, 1)")
            {
                REQUIRE((a1 + a2) == Tuple(1, 1, 6, 1));
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Adding two tuples without modify a1", "[features/tuples.feature]")
{
    GIVEN("a1 <-tuple(3, -2, 5, 1)")
    {
        Tuple a1(3, -2, 5, 1);
        AND_GIVEN("a2 <- tuple(-2, 3, 1, 0)")
        {
            Tuple a2(-2, 3, 1, 0);
            WHEN("a3 = a1 + a2")
            {
                Tuple a3 = a1 + a2;
                THEN("a1 + a2 = tuple(1, 1, 6, 1)")
                {
                    REQUIRE((a1 + a2) == Tuple(1, 1, 6, 1));
                }
                AND_THEN("a3 = a1 + a2")
                {
                    REQUIRE((a1 + a2) == a3);
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Subtracting two points", "[features/tuples.feature]")
{
    GIVEN("p1 <- point(3, 2, 1)")
    {
        Tuple p1 = Tuple::Point(3, 2, 1);
        AND_GIVEN("p2 <- point(5, 6, 7)")
        {
            Tuple p2 = Tuple::Point(5, 6, 7);
            THEN("p1 - p2 = vector(-2, -4, -6)")
            {
                REQUIRE((p1 - p2) == Tuple::Vector(-2, -4, -6));
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Subtracting two points without modify p1", "[features/tuples.feature]")
{
    GIVEN("p1 <- point(3, 2, 1)")
    {
        Tuple p1 = Tuple::Point(3, 2, 1);
        AND_GIVEN("p2 <- point(5, 6, 7)")
        {
            Tuple p2 = Tuple::Point(5, 6, 7);

            WHEN("p3 = p1 - p2")
            {
                Tuple p3 = p1 - p2;
                THEN("(p1 - p2) = vector(-2, -4, -6)")
                {
                    REQUIRE((p1 - p2) == Tuple::Vector(-2, -4, -6));
                }
                AND_THEN("p3 = p1 - p2")
                {
                    REQUIRE((p1 - p2) == p3);
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Subtracting a vector from a point", "[features/tuples.feature]")
{
    GIVEN("p <- point(3, 2, 1)")
    {
        Tuple p = Tuple::Point(3, 2, 1);

        AND_GIVEN("v <-vector(5, 6, 7)")
        {
            Tuple v = Tuple::Vector(5, 6, 7);
            THEN("p - v = point(-2, -4, -6)")
            {
                REQUIRE((p - v) == Tuple::Point(-2, -4, -6));
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Subtracting two vectors", "[features/tuples.feature]")
{
    GIVEN("v1 <-vector(3, 2, 1)")
    {
        Tuple v1 = Tuple::Vector(3, 2, 1);
        AND_GIVEN("v2 <-vector(5, 6, 7)")
        {
            Tuple v2 = Tuple::Vector(5, 6, 7);
            THEN("v1 - v2 = vector(-2, -4, -6)")
            {
                REQUIRE((v1 - v2) == Tuple::Vector(-2, -4, -6));
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Subtracting a vector from the zero vector", "[features/tuples.feature]")
{
    GIVEN("zero <-vector(0, 0, 0)")
    {
        Tuple zero = Tuple::Vector(0, 0, 0);
        AND_GIVEN("v <-vector(1, -2, 3)")
        {
            Tuple v = Tuple::Vector(1, -2, 3);
            THEN("zero - v = vector(-1, 2, -3)")
            {
                REQUIRE((zero - v) == Tuple::Vector(-1, 2, -3));
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Negative a tuple", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        THEN("-a = tuple(-1, 2, -3, 4)")
        {
            REQUIRE(-a == Tuple(-1, 2, -3, 4));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Multiplying a tuple by a scalar", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        THEN("a * 3.5 = tuple(3.5, -7, 10.5, -14)")
        {
            REQUIRE(a * 3.5 == Tuple(3.5, -7, 10.5, -14));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Multiplying a tuple by a scalar without modify a", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        WHEN("b = a * 3.5;")
        {
            Tuple b = a * 3.5;
            THEN("a * 3.5 = tuple(3.5, -7, 10.5, -14)")
            {
                REQUIRE(a * 3.5 == Tuple(3.5, -7, 10.5, -14));
            }
            AND_THEN("b = a * 3.5")
            {
                REQUIRE((a * 3.5) == b);
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Multiplying a tuple by a fraction", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        THEN("a * 0.5 = tuple(0.5, -1, 1.5, -2)")
        {
            REQUIRE(a * 0.5 == Tuple(0.5, -1, 1.5, -2));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Dividing a tuple by a scalar", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        THEN("a / 2 = tuple(0.5, -1, 1.5, -2)")
        {
            REQUIRE(a / 2 == Tuple(0.5, -1, 1.5, -2));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Dividing a tuple by a scalar without modify a", "[features/tuples.feature]")
{
    GIVEN("a <-tuple(1, -2, 3, -4)")
    {
        Tuple a(1, -2, 3, -4);
        WHEN("b = a / 2")
        {
            Tuple b = a / 2;
            THEN("a / 2 = tuple(0.5, -1, 1.5, -2)")
            {
                REQUIRE(a / 2 == Tuple(0.5, -1, 1.5, -2));
            }
            AND_THEN("b = a / 2")
            {
                REQUIRE((a / 2) == b);
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Computing the magnitude of vector(1,0,0)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(1, 0, 0)")
    {
        Tuple v = Tuple::Vector(1, 0, 0);
        THEN("magnitude(v) = 1")
        {
            REQUIRE(v.magnitude() == 1);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Computing the magnitude of vector(0,1,0)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(0, 1, 0)")
    {
        Tuple v = Tuple::Vector(0, 1, 0);

        THEN("magnitude(v) = 1")
        {
            REQUIRE(v.magnitude() == 1);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Computing the magnitude of vector(0,0,1)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(0, 0, 1)")
    {
        Tuple v = Tuple::Vector(0, 0, 1);

        THEN("magnitude(v) = 1")
        {
            REQUIRE(v.magnitude() == 1);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Computing the magnitude of vector(1,2,3)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(1, 2, 3)")
    {
        Tuple v = Tuple::Vector(1, 2, 3);

        THEN("magnitude(v) = sqrt(14)")
        {
            REQUIRE(v.magnitude() == sqrt(14));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Computing the magnitude of vector(-1,-2,-3)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(-1, -2, -3)")
    {
        Tuple v = Tuple::Vector(-1, -2, -3);

        THEN("magnitude(v) = sqrt(14)")
        {
            REQUIRE(v.magnitude() == sqrt(14));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Normalize vector(4,0,0) gives (1,0,0)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(4, 0, 0)")
    {
        Tuple v = Tuple::Vector(4, 0, 0);
        THEN("normalize(v) = vector(1, 0, 0)")
        {
            REQUIRE(v.normalize() == Tuple::Vector(1, 0, 0));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Normalize vector(1,2,3)", "[features/tuples.feature]")
{
    GIVEN("v <-vector(1, 2, 3)")
    {
        Tuple v = Tuple::Vector(1, 2, 3);
        // vector (1/sqrt(14), 2/sqrt(14), 3/sqrt(14))
        THEN("normalize(v) = approximately vector(0.26726, 0.53452, 0.80178)")
        {
            REQUIRE(v.normalize() == Tuple::Vector(1 / sqrtf(14), 2 / sqrtf(14), 3 / sqrtf(14)));
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("The magnitude of a normalized vector", "[features/tuples.feature]")
{
    GIVEN("v <-vector(1, 2, 3)")
    {
        Tuple v = Tuple::Vector(1, 2, 3);
        Tuple norm;
        WHEN("norm <- normalize(v)")
        {
            norm = v.normalize();
            THEN("magnitude(norm) = 1")
            {
                REQUIRE(norm.magnitude() == 1);
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("The dot product of two tuples", "[features/tuples.feature]")
{
    GIVEN("a <-vector(1, 2, 3)")
    {
        Tuple a = Tuple::Vector(1, 2, 3);

        AND_GIVEN("b <-vector(2, 3, 4)")
        {
            Tuple b = Tuple::Vector(2, 3, 4);
            THEN("dot(a,b) = 20")
            {
                REQUIRE(a.dot(b) == 20);
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("The cross product of two vectors", "[features/tuples.feature]")
{
    GIVEN("a <-vector(1, 2, 3)")
    {
        Tuple a = Tuple::Vector(1, 2, 3);
        AND_GIVEN("b <-vector(2, 3, 4)")
        {
            Tuple b = Tuple::Vector(2, 3, 4);
            THEN("cross(a,b) = vector(-1, 2, -1)")
            {
                REQUIRE(a.cross(b) == Tuple::Vector(-1, 2, -1));
            }
            AND_THEN("cross(b,a) = vector(1, -2, -1)")
            {
                REQUIRE(b.cross(a) == Tuple::Vector(1, -2, 1));
            }
        }
    }
}