#ifndef STAN_SERVICES_UTIL_READ_DENSE_INV_METRIC_HPP
#define STAN_SERVICES_UTIL_READ_DENSE_INV_METRIC_HPP

#include <stan/callbacks/logger.hpp>
#include <stan/io/var_context.hpp>
#include <stan/math/prim.hpp>
#include <limits>
#include <sstream>
#include <string>
#include <vector>

namespace stan {
namespace services {
namespace util {

/**
 * Extract dense inverse Euclidean metric from a var_context object.
 *
 * @param[in] init_context a var_context with array of initial values
 * @param[in] num_params expected number of row, column elements
 * @param[in,out] logger Logger for messages
 * @throws std::domain_error if cannot read the Euclidean metric
 * @return inv_metric
 */
inline Eigen::MatrixXd read_dense_inv_metric(
    const stan::io::var_context& init_context, size_t num_params,
    callbacks::logger& logger) {
  Eigen::MatrixXd inv_metric;
  try {
    init_context.validate_dims("read dense inv metric", "inv_metric", "matrix",
                               init_context.to_vec(num_params, num_params));
    std::vector<double> dense_vals = init_context.vals_r("inv_metric");
    inv_metric = stan::math::to_matrix(dense_vals, num_params, num_params);
  } catch (const std::exception& e) {
    logger.error("Cannot get inverse metric from input file.");
    logger.error("Caught exception: ");
    logger.error(e.what());
    throw std::domain_error("Initialization failure");
  }

  return inv_metric;
}

}  // namespace util
}  // namespace services
}  // namespace stan

#endif
