#ifndef FESA_TESTS_REFERENCE_REFERENCE_COMPARISON_H_
#define FESA_TESTS_REFERENCE_REFERENCE_COMPARISON_H_

#include <array>
#include <cstddef>
#include <cstdint>
#include <filesystem>
#include <string>
#include <vector>

#include "fesa/core/status.h"

namespace fesa::test {

enum class ComparisonQuantity { kDisplacement, kReaction, kSectionResultant };

struct CanonicalComparisonRow {
  std::string model_id;
  std::string step_name;
  std::size_t frame_index;
  std::string instance_name;
  std::int64_t source_node_label;
  std::int64_t source_element_label;
  int endpoint_index;
  ComparisonQuantity quantity;
  std::string component;
  double value;
  std::string unit_dimension;
  std::string coordinate_system;
  std::string hdf5_dataset_path;
};

struct RowDecision {
  CanonicalComparisonRow fesa;
  CanonicalComparisonRow reference;
  double absolute_error;
  double tolerance;
  double reference_scale;
  double near_zero_band;
  double relative_error;
  bool relative_error_applicable;
  std::string tolerance_branch;
  bool passed;
};

struct ComponentMetrics {
  ComparisonQuantity quantity;
  std::string family_identity;
  std::vector<std::string> components;
  double reference_scale;
  double near_zero_band;
  std::size_t near_zero_count;
  double maximum_absolute_error;
  double relative_rms;
  std::size_t worst_row;
  bool rms_passed;
  bool passed;
  std::string diagnostic_code;
  std::size_t row_count{};
};

struct PhysicsEvidence {
  double free_residual_norm;
  std::array<double, 3> applied_force;
  std::array<double, 3> reaction_force;
  std::array<double, 3> applied_moment_about_origin;
  std::array<double, 3> reaction_moment_about_origin;
  bool endpoint_consistency_passed;
};

struct ComparisonReport {
  std::vector<RowDecision> rows;
  std::vector<ComponentMetrics> metrics;
  PhysicsEvidence physics_evidence;
  bool stress_comparison_applicable;
  std::string stress_comparison_reason;
  bool passed;
};

// Test-only comparison support keeps Abaqus artifacts read-only and exposes no
// backend handles to the implementation or downstream verification Steps.
class ReferenceComparison {
 public:
  static Result<ComparisonReport> Compare(
      const std::filesystem::path& results_hdf5,
      const std::filesystem::path& legacy_reference_directory);
  static Status WriteDeterministicJson(
      const ComparisonReport& report, const std::filesystem::path& output_json);
};

}  // namespace fesa::test

#endif  // FESA_TESTS_REFERENCE_REFERENCE_COMPARISON_H_