// Arguments: Doubles, Doubles, Doubles, Doubles
#include <stan/math/prim/prob/exp_mod_normal_ccdf_log.hpp>
#include <stan/math/prim/fun/erf.hpp>
#include <stan/math/prim/fun/log.hpp>
#include <stan/math/prim/fun/sqrt.hpp>

using stan::math::var;
using std::numeric_limits;
using std::vector;

class AgradCcdfLogExpModNormal : public AgradCcdfLogTest {
 public:
  void valid_values(vector<vector<double> >& parameters,
                    vector<double>& ccdf_log) {
    vector<double> param(4);

    param[0] = 0;  // y
    param[1] = 0;  // mu
    param[2] = 1;  // sigma
    param[3] = 1;  // lambda
    parameters.push_back(param);
    ccdf_log.push_back(
        std::log(1.0 - 0.2384217081348766198445));  // expected ccdf_log

    param[0] = 1;  // y
    param[1] = 0;  // mu
    param[2] = 1;  // sigma
    param[3] = 1;  // lambda
    parameters.push_back(param);
    ccdf_log.push_back(
        std::log(1.0 - 0.538079416212226213645));  // expected ccdf_log
  }

  void invalid_values(vector<size_t>& index, vector<double>& value) {
    // y

    // mu
    index.push_back(1U);
    value.push_back(-numeric_limits<double>::infinity());

    index.push_back(1U);
    value.push_back(numeric_limits<double>::infinity());

    // sigma
    index.push_back(2U);
    value.push_back(-numeric_limits<double>::infinity());

    index.push_back(2U);
    value.push_back(-1.0);

    index.push_back(2U);
    value.push_back(0.0);

    // lambda
    index.push_back(3U);
    value.push_back(-numeric_limits<double>::infinity());

    index.push_back(3U);
    value.push_back(-1.0);

    index.push_back(3U);
    value.push_back(0.0);

    index.push_back(3U);
    value.push_back(numeric_limits<double>::infinity());
  }

  bool has_lower_bound() { return false; }

  bool has_upper_bound() { return false; }

  template <typename T_y, typename T_loc, typename T_scale,
            typename T_inv_scale, typename T4, typename T5>
  stan::return_type_t<T_y, T_loc, T_scale, T_inv_scale> ccdf_log(
      const T_y& y, const T_loc& mu, const T_scale& sigma,
      const T_inv_scale& lambda, const T4&, const T5&) {
    return stan::math::exp_mod_normal_ccdf_log(y, mu, sigma, lambda);
  }

  template <typename T_y, typename T_loc, typename T_scale,
            typename T_inv_scale, typename T4, typename T5>
  stan::return_type_t<T_y, T_loc, T_scale, T_inv_scale> ccdf_log_function(
      const T_y& y, const T_loc& mu, const T_scale& sigma,
      const T_inv_scale& lambda, const T4&, const T5&) {
    return log(
        1.0
        - (0.5 * (1 + erf((y - mu) / (sqrt(2.0) * sigma)))
           - exp(-lambda * (y - mu) + lambda * sigma * lambda * sigma / 2.0)
                 * 0.5
                 * (1
                    + erf(((y - mu) - sigma * lambda * sigma)
                          / (sqrt(2.0) * sigma)))));
  }
};
