#ifndef FESA_ANALYSIS_ANALYSIS_STATE_H_
#define FESA_ANALYSIS_ANALYSIS_STATE_H_

#include <array>
#include <cstddef>
#include <vector>

#include "fesa/core/status.h"
#include "fesa/fem/dof_manager.h"
#include "fesa/math/vector.h"
#include "fesa/results/result_records.h"

namespace fesa {

/// @brief Owns mutable quantities required by the V0 linear-static frame.
class AnalysisState {
 public:
  /// @brief Allocates zeroed full-DOF vectors for a DOF manager.
  /// @param dofs Owner of the full-DOF dimension used by every state vector.
  /// @param identity Stable step and frame identity for this state.
  static AnalysisState Create(const DofManager& dofs,
                              StepFrameIdentity identity);

  /// @brief Returns mutable full-space displacement.
  Vector& Displacement() noexcept;
  /// @brief Returns full-space displacement.
  const Vector& Displacement() const noexcept;
  /// @brief Returns mutable full-space external force.
  Vector& ExternalForce() noexcept;
  /// @brief Returns full-space external force.
  const Vector& ExternalForce() const noexcept;
  /// @brief Returns mutable full-space internal force.
  Vector& InternalForce() noexcept;
  /// @brief Returns full-space internal force.
  const Vector& InternalForce() const noexcept;
  /// @brief Returns mutable full residual K*d-F.
  Vector& Residual() noexcept;
  /// @brief Returns full residual K*d-F.
  const Vector& Residual() const noexcept;
  /// @brief Returns mutable full-index reaction and free residual evidence.
  Vector& Reaction() noexcept;
  /// @brief Returns full-index reaction and free residual evidence.
  const Vector& Reaction() const noexcept;
  /// @brief Returns the stable step and frame identity.
  const StepFrameIdentity& Identity() const noexcept;
  /// @brief Returns mutable beam endpoint result rows.
  std::vector<EndpointResultRow>& EndpointResults() noexcept;
  /// @brief Returns beam endpoint result rows.
  const std::vector<EndpointResultRow>& EndpointResults() const noexcept;
  /// @brief Returns mutable beam Gauss result rows.
  std::vector<GaussResultRow>& GaussResults() noexcept;
  /// @brief Returns beam Gauss result rows.
  const std::vector<GaussResultRow>& GaussResults() const noexcept;
  /// @brief Returns mutable beam axial-stress rows.
  std::vector<StressS11Row>& StressResults() noexcept;
  /// @brief Returns beam axial-stress rows.
  const std::vector<StressS11Row>& StressResults() const noexcept;

  /// @brief Validates and atomically replaces all shell recovery evidence.
  /// @param expected_element_order Unique shell indices in stable order.
  /// @param candidate Complete shell rows, energy, and equilibrium evidence.
  /// @return Success only after the complete candidate is validated and
  /// committed; failure preserves the prior shell state.
  Status CommitShellResults(
      const std::vector<EntityIndex>& expected_element_order,
      ShellStateCandidate candidate);

  /// @brief Returns shell rows in stable element and location order.
  const std::vector<ShellResultRow>& ShellResults() const noexcept;
  /// @brief Returns physical shell strain energy without drilling energy.
  double PhysicalStrainEnergy() const noexcept;
  /// @brief Returns global force and moment equilibrium components.
  const std::array<double, 6>& Equilibrium() const noexcept;
  /// @brief Returns normalized shell verification metrics.
  const std::array<double, 3>& VerificationMetrics() const noexcept;

 private:
  /// @brief Allocates state storage for one stable full-DOF dimension.
  AnalysisState(std::size_t full_dof_count, StepFrameIdentity identity);

  StepFrameIdentity identity_;
  Vector displacement_;
  Vector external_force_;
  Vector internal_force_;
  Vector residual_;
  // Reactions retain full-index space so free residual components remain
  // visible.
  Vector reaction_;
  // Recovery appends rows in stable element/location order.
  std::vector<EndpointResultRow> endpoint_results_;
  std::vector<GaussResultRow> gauss_results_;
  std::vector<StressS11Row> stress_results_;
  // Shell recovery is replaced only through validated candidate commit.
  std::vector<ShellResultRow> shell_results_;
  double physical_strain_energy_{0.0};
  std::array<double, 6> equilibrium_{};
  std::array<double, 3> verification_metrics_{};
};

}  // namespace fesa

#endif  // FESA_ANALYSIS_ANALYSIS_STATE_H_