#ifndef FESA_MATH_MATRIX_H_
#define FESA_MATH_MATRIX_H_

#include <cstddef>
#include <vector>

#include "fesa/math/vector.h"

namespace fesa {

/// @brief Owns row-major contiguous storage independently of sparse matrices.
class Matrix {
 public:
  /// @brief Constructs a row-major matrix initialized to one value.
  Matrix(std::size_t rows, std::size_t columns, double value = 0.0);

  /// @brief Copies matrix values into independent contiguous storage.
  Matrix(const Matrix& other);

  /// @brief Moves matrix storage and resets other to a zero-by-zero shape.
  Matrix(Matrix&& other) noexcept;

  /// @brief Copies matrix values into independent contiguous storage.
  Matrix& operator=(const Matrix& other);

  /// @brief Moves matrix storage and resets other to a zero-by-zero shape.
  Matrix& operator=(Matrix&& other) noexcept;

  /// @brief Returns the row count.
  std::size_t Rows() const noexcept;

  /// @brief Returns the column count.
  std::size_t Columns() const noexcept;

  /// @brief Returns a bounds-checked mutable entry.
  /// @throws std::out_of_range if the index is outside the matrix.
  double& operator()(std::size_t row, std::size_t column);

  /// @brief Returns a bounds-checked immutable entry.
  /// @throws std::out_of_range if the index is outside the matrix.
  const double& operator()(std::size_t row, std::size_t column) const;

  /// @brief Multiplies this row-major matrix by a dense vector.
  /// @throws std::invalid_argument if the dimensions are incompatible.
  Vector Multiply(const Vector& rhs) const;

  /// @brief Multiplies this row-major matrix by another dense matrix.
  /// @throws std::invalid_argument if the dimensions are incompatible.
  Matrix Multiply(const Matrix& rhs) const;

 private:
  std::size_t rows_;
  std::size_t columns_;
  std::vector<double> values_;
};

}  // namespace fesa

#endif  // FESA_MATH_MATRIX_H_