#ifndef FESA_ANALYSIS_ANALYSIS_MODEL_H_
#define FESA_ANALYSIS_ANALYSIS_MODEL_H_

#include <vector>

#include "fesa/model/domain.h"

namespace fesa {

/// @brief Provides the active-step view into a non-owned Domain.
/// @note The referenced Domain must outlive this object and retains all
/// semantic ownership.
class AnalysisModel {
 public:
  /// @brief Creates the sole active-step view for a valid Domain.
  /// @param domain Domain that remains alive for the returned view's lifetime.
  /// @return A stable view or an input-cardinality failure.
  static Result<AnalysisModel> Create(const Domain& domain);

  /// @brief Returns the non-owned Domain backing this view.
  const Domain& GetDomain() const noexcept;

  /// @brief Returns the sole active structural step.
  /// @throws std::logic_error when this is a thermal view.
  /// @note Thermal callers must use ThermalStep().
  const StepDefinition& Step() const;

  /// @brief Reports whether this view selects the uncoupled thermal step.
  bool IsThermal() const noexcept;

  /// @brief Returns the selected thermal step, or null for structural views.
  const ThermalStepDefinition* ThermalStep() const noexcept;

  /// @brief Returns active element-definition indices in stable Domain order.
  const std::vector<EntityIndex>& ActiveElements() const noexcept;

  /// @brief Returns active B33 indices in their concrete compatibility view.
  const std::vector<EntityIndex>& ActiveBeamElements() const noexcept;

  /// @brief Returns reachable material indices in stable internal order.
  const std::vector<EntityIndex>& ActiveMaterials() const noexcept;

  /// @brief Returns reachable property indices in stable internal order.
  const std::vector<EntityIndex>& ActiveProperties() const noexcept;

  /// @brief Returns reachable beam-section indices in stable internal order.
  const std::vector<EntityIndex>& ActiveSections() const noexcept;

  /// @brief Returns boundary-condition indices in source order.
  const std::vector<EntityIndex>& ActiveBoundaryConditions() const noexcept;

  /// @brief Returns concentrated-load indices in source order.
  const std::vector<EntityIndex>& ActiveLoads() const noexcept;

  /// @brief Returns connected DS4 element indices in stable Domain order.
  const std::vector<EntityIndex>& ActiveThermalElements() const noexcept;

  /// @brief Returns connected thermal node indices in stable Domain order.
  const std::vector<EntityIndex>& ActiveThermalNodes() const noexcept;

  /// @brief Returns thermal-material collection positions in source order.
  const std::vector<EntityIndex>& ActiveThermalMaterials() const noexcept;

  /// @brief Returns thermal-section collection positions in source order.
  const std::vector<EntityIndex>& ActiveThermalSections() const noexcept;

  /// @brief Returns active surface pressure records without copying Domain data.
  const std::vector<SurfacePressureLoadDefinition>& ActiveSurfacePressureLoads()
      const noexcept;

 private:
  /// @brief Builds stable indices without copying the referenced Domain.
  explicit AnalysisModel(const Domain& domain);

  const Domain* domain_;
  std::vector<EntityIndex> active_elements_;
  std::vector<EntityIndex> active_beam_elements_;
  std::vector<EntityIndex> active_materials_;
  std::vector<EntityIndex> active_properties_;
  std::vector<EntityIndex> active_sections_;
  std::vector<EntityIndex> active_boundary_conditions_;
  std::vector<EntityIndex> active_loads_;
  std::vector<EntityIndex> active_thermal_elements_;
  std::vector<EntityIndex> active_thermal_nodes_;
  std::vector<EntityIndex> active_thermal_materials_;
  std::vector<EntityIndex> active_thermal_sections_;
  bool is_thermal_{false};
};

}  // namespace fesa

#endif  // FESA_ANALYSIS_ANALYSIS_MODEL_H_