// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

#include <Eigen/CXX11/Tensor>

using Eigen::Tensor;
using Eigen::RowMajor;

static void test_1d()
{
  Tensor<float, 1> vec1({6});
  Tensor<float, 1, RowMajor> vec2({6});

  vec1(0) = 4.0;  vec2(0) = 0.0;
  vec1(1) = 8.0;  vec2(1) = 1.0;
  vec1(2) = 15.0; vec2(2) = 2.0;
  vec1(3) = 16.0; vec2(3) = 3.0;
  vec1(4) = 23.0; vec2(4) = 4.0;
  vec1(5) = 42.0; vec2(5) = 5.0;

  float data3[6];
  TensorMap<Tensor<float, 1>> vec3(data3, 6);
  vec3 = vec1.cwiseSqrt();
  float data4[6];
  TensorMap<Tensor<float, 1, RowMajor>> vec4(data4, 6);
  vec4 = vec2.cwiseSqrt();

  VERIFY_IS_APPROX(vec3(0), sqrtf(4.0));
  VERIFY_IS_APPROX(vec3(1), sqrtf(8.0));
  VERIFY_IS_APPROX(vec3(2), sqrtf(15.0));
  VERIFY_IS_APPROX(vec3(3), sqrtf(16.0));
  VERIFY_IS_APPROX(vec3(4), sqrtf(23.0));
  VERIFY_IS_APPROX(vec3(5), sqrtf(42.0));

  VERIFY_IS_APPROX(vec4(0), sqrtf(0.0));
  VERIFY_IS_APPROX(vec4(1), sqrtf(1.0));
  VERIFY_IS_APPROX(vec4(2), sqrtf(2.0));
  VERIFY_IS_APPROX(vec4(3), sqrtf(3.0));
  VERIFY_IS_APPROX(vec4(4), sqrtf(4.0));
  VERIFY_IS_APPROX(vec4(5), sqrtf(5.0));

  vec3 = vec1 + vec2;
  VERIFY_IS_APPROX(vec3(0), 4.0f + 0.0f);
  VERIFY_IS_APPROX(vec3(1), 8.0f + 1.0f);
  VERIFY_IS_APPROX(vec3(2), 15.0f + 2.0f);
  VERIFY_IS_APPROX(vec3(3), 16.0f + 3.0f);
  VERIFY_IS_APPROX(vec3(4), 23.0f + 4.0f);
  VERIFY_IS_APPROX(vec3(5), 42.0f + 5.0f);
}

static void test_2d()
{
  float data1[6];
  TensorMap<Tensor<float, 2>> mat1(data1, 2, 3);
  float data2[6];
  TensorMap<Tensor<float, 2, RowMajor>> mat2(data2, 2, 3);

  mat1(0,0) = 0.0;
  mat1(0,1) = 1.0;
  mat1(0,2) = 2.0;
  mat1(1,0) = 3.0;
  mat1(1,1) = 4.0;
  mat1(1,2) = 5.0;

  mat2(0,0) = -0.0;
  mat2(0,1) = -1.0;
  mat2(0,2) = -2.0;
  mat2(1,0) = -3.0;
  mat2(1,1) = -4.0;
  mat2(1,2) = -5.0;

  Tensor<float, 2> mat3(2,3);
  Tensor<float, 2, RowMajor> mat4(2,3);
  mat3 = mat1.cwiseAbs();
  mat4 = mat2.cwiseAbs();

  VERIFY_IS_APPROX(mat3(0,0), 0.0f);
  VERIFY_IS_APPROX(mat3(0,1), 1.0f);
  VERIFY_IS_APPROX(mat3(0,2), 2.0f);
  VERIFY_IS_APPROX(mat3(1,0), 3.0f);
  VERIFY_IS_APPROX(mat3(1,1), 4.0f);
  VERIFY_IS_APPROX(mat3(1,2), 5.0f);

  VERIFY_IS_APPROX(mat4(0,0), 0.0f);
  VERIFY_IS_APPROX(mat4(0,1), 1.0f);
  VERIFY_IS_APPROX(mat4(0,2), 2.0f);
  VERIFY_IS_APPROX(mat4(1,0), 3.0f);
  VERIFY_IS_APPROX(mat4(1,1), 4.0f);
  VERIFY_IS_APPROX(mat4(1,2), 5.0f);
}

static void test_3d()
{
  Tensor<float, 3> mat1(2,3,7);
  Tensor<float, 3, RowMajor> mat2(2,3,7);

  float val = 0.0;
  for (int i = 0; i < 2; ++i) {
    for (int j = 0; j < 3; ++j) {
      for (int k = 0; k < 7; ++k) {
        mat1(i,j,k) = val;
        mat2(i,j,k) = val;
        val += 1.0;
      }
    }
  }

  Tensor<float, 3> mat3(2,3,7);
  mat3 = mat1 + mat1;
  Tensor<float, 3, RowMajor> mat4(2,3,7);
  mat4 = mat2 * 3.14f;
  Tensor<float, 3> mat5(2,3,7);
  mat5 = mat1.cwiseSqrt().cwiseSqrt();
  Tensor<float, 3, RowMajor> mat6(2,3,7);
  mat6 = mat2.cwiseSqrt() * 3.14f;

  val = 0.0;
  for (int i = 0; i < 2; ++i) {
    for (int j = 0; j < 3; ++j) {
      for (int k = 0; k < 7; ++k) {
        VERIFY_IS_APPROX(mat3(i,j,k), val + val);
        VERIFY_IS_APPROX(mat4(i,j,k), val * 3.14f);
        VERIFY_IS_APPROX(mat5(i,j,k), sqrtf(sqrtf(val)));
        VERIFY_IS_APPROX(mat6(i,j,k), sqrtf(val) * 3.14f);
        val += 1.0;
      }
    }
  }
}


void test_cxx11_tensor_expr()
{
  CALL_SUBTEST(test_1d());
  CALL_SUBTEST(test_2d());
  CALL_SUBTEST(test_3d());
}