#ifndef STAN_LANG_GENERATOR_GENERATE_UNCONSTRAINED_PARAM_NAMES_ARRAY_HPP
#define STAN_LANG_GENERATOR_GENERATE_UNCONSTRAINED_PARAM_NAMES_ARRAY_HPP

#include <stan/lang/ast.hpp>
#include <stan/lang/generator/constants.hpp>
#include <stan/lang/generator/generate_expression.hpp>
#include <stan/lang/generator/generate_indent.hpp>
#include <stan/lang/generator/get_block_var_dims.hpp>
#include <stan/lang/generator/write_begin_param_elements_loop.hpp>
#include <stan/lang/generator/write_end_loop.hpp>
#include <ostream>
#include <string>
#include <vector>

namespace stan {
namespace lang {

/**
 * Generate the sequence of names for all elements of a parameter variable.
 *
 * @param[in] indent level of indentation
 * @param[in,out] o stream for generating
 * @param[in] var_decl block variable declaraton ast node
 */
void generate_unconstrained_param_names_array(size_t indent, std::ostream& o,
                                              const block_var_decl& var_decl) {
  std::string var_name(var_decl.name());
  block_var_type vtype = var_decl.type();
  size_t num_array_dims = vtype.array_dims();
  size_t num_vector_dims = vtype.num_dims() - vtype.array_dims();
  if (var_decl.type().innermost_type().is_specialized()) {
    num_vector_dims = 1;
  }
  size_t num_loops = vtype.array_dims() + num_vector_dims;

  write_begin_param_elements_loop(var_decl, true, indent, o);

  generate_indent(indent + num_loops, o);
  o << "param_name_stream__.str(std::string());" << EOL;

  generate_indent(indent + num_loops, o);
  o << "param_name_stream__ << " << '"' << var_name << '"';

  for (size_t i = 0; i < num_array_dims; ++i)
    o << " << '.' << k_" << i << "__ + 1";
  if (num_vector_dims == 1)
    o << " << '.' << j_1__ + 1";
  else if (num_vector_dims == 2)
    o << " << '.' << j_1__ + 1 << '.' << j_2__ + 1";
  o << ';' << EOL;

  generate_indent(indent + num_loops, o);
  o << "param_names__.push_back(param_name_stream__.str());" << EOL;

  write_end_loop(num_loops, indent, o);
}

}  // namespace lang
}  // namespace stan
#endif
