#include <gtest/gtest.h>
#include <J3ML/Geometry/Triangle.h>

using J3ML::Geometry::Interval;
using J3ML::Geometry::Triangle;

TEST(TriangleTests, FaceNormal)
{
    Triangle t{
        Vector3{-1, -1, -1},
        Vector3{0,   1,  0},
        Vector3{1,  -1,  1}
    };

    EXPECT_EQ(t.FaceNormal(), (Vector3{4, 0, -4}));
}

TEST(TriangleTests, IntersectTriangle)
{
    Triangle xyTriangle{
        {0.0f, 0.0f, 0.0f},
        {1.0f, 1.0f, 0.0f},
        {2.0f, 0.0f, 0.0f}
    };

    // Triangle collides with itself
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle), true);
    // Translate 1 towards x -- should collide
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(1.0f, 0.0f, 0.0f))), true);
    // Translate 2 towards x -- should collide exactly on V1
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(2.0f, 0.0f, 0.0f))), true);
    // Translate 2 towards negative x -- should collide exactly on V0
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(-2.0f, 0.0f, 0.0f))), true);
    // Translate 3 towards x -- should not collide
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(3.0f, 0.0f, 0.0f))), false);
    // Translate 3 towards negative x -- should not collide
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(-3.0f, 0.0f, 0.0f))), false);
    // Translate 1 towards z -- should not collide
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Translated(Vector3(0.0f, 0.0f, 1.0f))), false);
    // Triangle collides with contained smaller triangle
    EXPECT_EQ(Intersects(xyTriangle, xyTriangle.Scaled(Vector3(0.5f, 0.5f, 0.5f)).Translated(Vector3(0.25f, 0.25f, 0.0f))), true);

    Triangle zxTriangle {
        {0.0f, 0.0f, 0.0f},
        {1.0f, 0.0f, 1.0f},
        {0.0f, 0.0f, 2.0f}
    };

    // Should collide exactly on V0
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle), true);
    // Should collide across xyTriangle's edge and  zxTriangle's face
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -1.0))), true);
    // Should collide exactly on V1
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -2.0))), true);
    // xyTriangle's face should be poked by zxTriangle's V0
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, 0.0f))), true);
    // xyTriangle's face should be cut by zxTriangle
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, -0.5f))), true);
    // Should not collide
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(1.0f, 1.0f, 1.0f))), false);
    // Should not collide
    EXPECT_EQ(Intersects(xyTriangle, zxTriangle.Translated(Vector3(0.0f, 0.0f, -3.0f))), false);

    Triangle yxTriangle{
        {0.0f, 0.0f, 0.0f},
        {1.0f, 1.0f, 0.0f},
        {0.0f, 2.0f, 0.0f}
    };

    // Should collide on V0-V1 edge
    EXPECT_EQ(Intersects(yxTriangle, yxTriangle), true);
    // Should not collide
    EXPECT_EQ(Intersects(xyTriangle, yxTriangle.Translated(Vector3(0.0f, 1.0f, 0.0f))), false);
    // Should not collide
    EXPECT_EQ(Intersects(yxTriangle, yxTriangle.Translated(Vector3(0.0f, 0.0f, 1.0f))), false);

    Triangle zyInvertedTriangle{
        {0.0f, 1.0f, -1.0f},
        {0.0f, 0.0f, 0.0f},
        {0.0f, 1.0f, 1.0f}
    };
    // Should collide exactly on V1
    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle), true);
    // Should not collide
    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle.Translated(Vector3(0.0f, 1.0f, 0.0f))), false);
    // Should not collide
    EXPECT_EQ(Intersects(xyTriangle, zyInvertedTriangle.Translated(Vector3(0.25f, 0.75f, 0.0f))), false);
}