#include "fesa/analysis/analysis_state.h"

#include <gtest/gtest.h>

#include <filesystem>
#include <iterator>
#include <type_traits>
#include <utility>

namespace {

template <class T, class = void>
struct HasVelocity : std::false_type {};

template <class T>
struct HasVelocity<T, std::void_t<decltype(std::declval<T&>().Velocity())>>
    : std::true_type {};

template <class T, class = void>
struct HasAcceleration : std::false_type {};

template <class T>
struct HasAcceleration<T,
                       std::void_t<decltype(std::declval<T&>().Acceleration())>>
    : std::true_type {};

template <class T, class = void>
struct HasTemperature : std::false_type {};

template <class T>
struct HasTemperature<T,
                      std::void_t<decltype(std::declval<T&>().Temperature())>>
    : std::true_type {};

template <class T, class = void>
struct HasIterationHistory : std::false_type {};

template <class T>
struct HasIterationHistory<
    T, std::void_t<decltype(std::declval<T&>().IterationHistory())>>
    : std::true_type {};

template <class T, class = void>
struct HasNonlinearState : std::false_type {};

template <class T>
struct HasNonlinearState<
    T, std::void_t<decltype(std::declval<T&>().NonlinearState())>>
    : std::true_type {};

fesa::DofManager MakeDofs() {
  fesa::ModelDefinition definition{};
  definition.source_path = "models/analysis-state.inp";
  definition.source_content_identity = "fnv1a64:0123456789abcdef";
  definition.nodes = {
      {{"Beam-1", 1, "1"}, {0.0, 0.0, 0.0}, {definition.source_path, 10U}},
      {{"Beam-1", 2, "2"}, {1.0, 0.0, 0.0}, {definition.source_path, 11U}}};
  definition.steps = {{"Step-1",
                       {{"1", 1, 6, 0.0, {definition.source_path, 20U}}},
                       {},
                       0.1,
                       1.0,
                       0.01,
                       1.0,
                       {definition.source_path, 19U}}};

  auto domain = fesa::Domain::Create(std::move(definition));
  EXPECT_TRUE(domain.HasValue());
  auto model = fesa::AnalysisModel::Create(domain.Value());
  EXPECT_TRUE(model.HasValue());
  auto dofs = fesa::DofManager::Create(model.Value());
  EXPECT_TRUE(dofs.HasValue());
  return std::move(dofs.Value());
}

void ExpectAllZero(const fesa::Vector& vector) {
  for (std::size_t index = 0U; index < vector.Size(); ++index) {
    EXPECT_DOUBLE_EQ(vector[index], 0.0);
  }
}

}  // namespace

TEST(AnalysisState, AllocatesOnlyV0FullVectors) {
  const auto dofs = MakeDofs();
  ASSERT_EQ(dofs.FullDofCount(), 12U);
  ASSERT_EQ(dofs.ConstrainedDofCount(), 6U);

  auto state = fesa::AnalysisState::Create(dofs, {"Step-1", 0U});
  const fesa::AnalysisState& const_state = state;
  const fesa::Vector* const vectors[] = {
      &const_state.Displacement(), &const_state.ExternalForce(),
      &const_state.InternalForce(), &const_state.Residual(),
      &const_state.Reaction()};

  for (const auto* vector : vectors) {
    EXPECT_EQ(vector->Size(), dofs.FullDofCount());
    ExpectAllZero(*vector);
  }
  for (std::size_t left = 0U; left < std::size(vectors); ++left) {
    for (std::size_t right = left + 1U; right < std::size(vectors); ++right) {
      EXPECT_NE(vectors[left]->Data(), vectors[right]->Data());
    }
  }

  state.Displacement()[0] = 4.0;
  state.Reaction()[11] = -9.0;
  EXPECT_DOUBLE_EQ(state.Displacement()[0], 4.0);
  EXPECT_DOUBLE_EQ(state.Reaction()[11], -9.0);
  EXPECT_DOUBLE_EQ(state.ExternalForce()[0], 0.0);
  EXPECT_DOUBLE_EQ(state.InternalForce()[0], 0.0);
  EXPECT_DOUBLE_EQ(state.Residual()[0], 0.0);

  EXPECT_FALSE(HasVelocity<fesa::AnalysisState>::value);
  EXPECT_FALSE(HasAcceleration<fesa::AnalysisState>::value);
  EXPECT_FALSE(HasTemperature<fesa::AnalysisState>::value);
  EXPECT_FALSE(HasIterationHistory<fesa::AnalysisState>::value);
  EXPECT_FALSE(HasNonlinearState<fesa::AnalysisState>::value);
}

TEST(AnalysisState, CopiesOrMovesWithoutAliasing) {
  static_assert(std::is_copy_constructible_v<fesa::AnalysisState>);
  static_assert(std::is_copy_assignable_v<fesa::AnalysisState>);
  static_assert(std::is_move_constructible_v<fesa::AnalysisState>);
  static_assert(std::is_move_assignable_v<fesa::AnalysisState>);

  const auto dofs = MakeDofs();
  auto original = fesa::AnalysisState::Create(dofs, {"Step-1", 0U});
  original.Displacement()[0] = 3.0;
  original.Reaction()[11] = -2.0;
  original.EndpointResults().push_back({0U,
                                        -1,
                                        {"Beam-1", 1, "1"},
                                        {1.0, 0.0, 0.0, 0.0, 0.0, 0.0},
                                        {2.0, 0.0, 0.0, 0.0}});
  original.GaussResults().push_back(
      {0U, 1, {0.1, 0.0, 0.0, 0.0}, {10.0, 0.0, 0.0, 0.0}});
  original.StressResults().push_back(
      {0U, 1, 0U, 0.0, 0.0, 10.0, "fesa-default"});

  auto copied = original;
  EXPECT_NE(copied.Displacement().Data(), original.Displacement().Data());
  EXPECT_NE(copied.Reaction().Data(), original.Reaction().Data());
  EXPECT_NE(copied.EndpointResults().data(), original.EndpointResults().data());
  EXPECT_NE(copied.GaussResults().data(), original.GaussResults().data());
  EXPECT_NE(copied.StressResults().data(), original.StressResults().data());
  copied.Displacement()[0] = 30.0;
  copied.EndpointResults()[0].end_action[0] = 20.0;
  EXPECT_DOUBLE_EQ(original.Displacement()[0], 3.0);
  EXPECT_DOUBLE_EQ(original.EndpointResults()[0].end_action[0], 1.0);

  auto moved = std::move(copied);
  EXPECT_EQ(moved.Identity().step_name, "Step-1");
  EXPECT_DOUBLE_EQ(moved.Displacement()[0], 30.0);
  EXPECT_DOUBLE_EQ(moved.EndpointResults()[0].end_action[0], 20.0);
  EXPECT_NE(moved.Displacement().Data(), original.Displacement().Data());
  EXPECT_NE(moved.EndpointResults().data(), original.EndpointResults().data());

  auto copy_assigned = fesa::AnalysisState::Create(dofs, {"Other", 3U});
  copy_assigned = original;
  copy_assigned.Reaction()[11] = -20.0;
  EXPECT_DOUBLE_EQ(original.Reaction()[11], -2.0);
  EXPECT_EQ(copy_assigned.Identity().step_name, "Step-1");

  auto move_assigned = fesa::AnalysisState::Create(dofs, {"Other", 4U});
  move_assigned = std::move(copy_assigned);
  EXPECT_EQ(move_assigned.Identity().step_name, "Step-1");
  EXPECT_DOUBLE_EQ(move_assigned.Reaction()[11], -20.0);
  EXPECT_NE(move_assigned.Reaction().Data(), original.Reaction().Data());
}