//  Copyright John Maddock 2006.
//  Copyright Paul A. Bristow 2007, 2009
//  Copyright Matt Borland 2024.
//  Use, modification and distribution are subject to the
//  Boost Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#include <boost/math/tools/config.hpp>
#include <boost/math/concepts/real_concept.hpp>
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <boost/math/special_functions/math_fwd.hpp>
#include <boost/math/constants/constants.hpp>
#include <boost/type_traits/is_floating_point.hpp>
#include <boost/array.hpp>
#include "functor.hpp"

#include "handle_test_result.hpp"
#include "table_type.hpp"

#ifndef SC_
#define SC_(x) static_cast<typename table_type<T>::type>(BOOST_JOIN(x, L))
#endif

#ifdef BOOST_MATH_NO_EXCEPTIONS
#  undef BOOST_CHECK_THROW
#  define BOOST_CHECK_THROW(x, y)
#endif

template <class Real, class T>
void do_test_erf(const T& data, const char* type_name, const char* test_name)
{
   typedef Real                   value_type;

   typedef value_type (*pg)(value_type);
#ifdef ERF_FUNCTION_TO_TEST
   pg funcp = ERF_FUNCTION_TO_TEST;
#elif defined(BOOST_MATH_NO_DEDUCED_FUNCTION_POINTERS)
   pg funcp = boost::math::erf<value_type>;
#else
   pg funcp = boost::math::erf;
#endif

   boost::math::tools::test_result<value_type> result;

   std::cout << "Testing " << test_name << " with type " << type_name
      << "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n";

   //
   // test erf against data:
   //
#if !(defined(ERROR_REPORTING_MODE) && !defined(ERF_FUNCTION_TO_TEST))
   result = boost::math::tools::test_hetero<Real>(
      data,
      bind_func<Real>(funcp, 0),
      extract_result<Real>(1));
   handle_test_result(result, data[result.worst()], result.worst(), type_name, "erf", test_name);
#endif
   //
   // test erfc against data:
   //
#ifdef ERFC_FUNCTION_TO_TEST
   funcp = ERFC_FUNCTION_TO_TEST;
#elif defined(BOOST_MATH_NO_DEDUCED_FUNCTION_POINTERS)
   funcp = boost::math::erfc<value_type>;
#else
   funcp = boost::math::erfc;
#endif
#if !(defined(ERROR_REPORTING_MODE) && !defined(ERFC_FUNCTION_TO_TEST))
   result = boost::math::tools::test_hetero<Real>(
      data,
      bind_func<Real>(funcp, 0),
      extract_result<Real>(2));
   handle_test_result(result, data[result.worst()], result.worst(), type_name, "erfc", test_name);
   std::cout << std::endl;
#endif
}


template <class Real, class T>
void do_test_erf_inv(const T& data, const char* type_name, const char* test_name)
{
#if !(defined(ERROR_REPORTING_MODE) && !defined(ERF_INV_FUNCTION_TO_TEST))
   typedef Real                   value_type;

   typedef value_type (*pg)(value_type);

   boost::math::tools::test_result<value_type> result;
   std::cout << "Testing " << test_name << " with type " << type_name
      << "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n";
   //
   // test erf_inv against data:
   //
#ifdef ERF_INV_FUNCTION_TO_TEST
   pg funcp = ERF_INV_FUNCTION_TO_TEST;
#elif defined(BOOST_MATH_NO_DEDUCED_FUNCTION_POINTERS)
   pg funcp = boost::math::erf_inv<value_type>;
#else
   pg funcp = boost::math::erf_inv;
#endif
   result = boost::math::tools::test_hetero<Real>(
      data,
      bind_func<Real>(funcp, 0),
      extract_result<Real>(1));
   handle_test_result(result, data[result.worst()], result.worst(), type_name, "erf_inv", test_name);
   std::cout << std::endl;
#endif
}

template <class Real, class T>
void do_test_erfc_inv(const T& data, const char* type_name, const char* test_name)
{
#if !(defined(ERROR_REPORTING_MODE) && !defined(ERFC_INV_FUNCTION_TO_TEST))
   typedef Real                   value_type;

   typedef value_type (*pg)(value_type);

   boost::math::tools::test_result<value_type> result;
   std::cout << "Testing " << test_name << " with type " << type_name
      << "\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n";
   //
   // test erfc_inv against data:
   //
#ifdef ERFC_INV_FUNCTION_TO_TEST
   pg funcp = ERFC_INV_FUNCTION_TO_TEST;
#elif defined(BOOST_MATH_NO_DEDUCED_FUNCTION_POINTERS)
   pg funcp = boost::math::erfc_inv<value_type>;
#else
   pg funcp = boost::math::erfc_inv;
#endif
   result = boost::math::tools::test_hetero<Real>(
      data,
      bind_func<Real>(funcp, 0),
      extract_result<Real>(1));
   handle_test_result(result, data[result.worst()], result.worst(), type_name, "erfc_inv", test_name);
   std::cout << std::endl;
#endif
}

template <class T>
void test_erf(T, const char* name)
{
   //
   // The actual test data is rather verbose, so it's in a separate file
   //
   // The contents are as follows, each row of data contains
   // three items, input value a, input value b and erf(a, b):
   //
#  include "erf_small_data.ipp"

   do_test_erf<T>(erf_small_data, name, "Erf Function: Small Values");

#  include "erf_data.ipp"

   do_test_erf<T>(erf_data, name, "Erf Function: Medium Values");

#  include "erf_large_data.ipp"

   do_test_erf<T>(erf_large_data, name, "Erf Function: Large Values");

#  include "erf_inv_data.ipp"

   do_test_erf_inv<T>(erf_inv_data, name, "Inverse Erf Function");

#  include "erfc_inv_data.ipp"

   do_test_erfc_inv<T>(erfc_inv_data, name, "Inverse Erfc Function");

#  include "erfc_inv_big_data.ipp"

   if(std::numeric_limits<T>::min_exponent <= -4500)
   {
      do_test_erfc_inv<T>(erfc_inv_big_data, name, "Inverse Erfc Function: extreme values");
   }

   BOOST_CHECK_EQUAL(boost::math::erf(T(0)), T(0));
   BOOST_CHECK_EQUAL(boost::math::erfc(T(0)), T(1));

   BOOST_CHECK(boost::math::erf(boost::math::tools::root_epsilon<T>() / 8) > T(0));
   BOOST_CHECK(boost::math::erf(boost::math::tools::epsilon<T>() / 32) >= T(0));
   BOOST_CHECK(boost::math::erfc(boost::math::tools::epsilon<T>() / 32) <= T(1));

   const bool has_negative_zero { ((boost::math::signbit)(-T(0)) != 0) };

   if(has_negative_zero)
   {
      BOOST_CHECK_EQUAL(boost::math::erf(-T(0)), -T(0));
   }

   BOOST_IF_CONSTEXPR(std::numeric_limits<T>::has_quiet_NaN)
   {
      BOOST_CHECK_THROW(boost::math::erf(std::numeric_limits<T>::quiet_NaN()), std::domain_error);
      BOOST_CHECK_THROW(boost::math::erfc(std::numeric_limits<T>::quiet_NaN()), std::domain_error);
   }
   BOOST_CHECK_THROW(boost::math::erfc_inv(T(-0.5)), std::domain_error);
   BOOST_CHECK_THROW(boost::math::erfc_inv(T(2.1)), std::domain_error);
   BOOST_CHECK_THROW(boost::math::erf_inv(T(-1.1)), std::domain_error);
   BOOST_CHECK_THROW(boost::math::erf_inv(T(1.1)), std::domain_error);
   BOOST_IF_CONSTEXPR(std::numeric_limits<T>::has_infinity)
   {
      BOOST_CHECK_EQUAL(boost::math::erfc_inv(T(0)), std::numeric_limits<T>::infinity());
      BOOST_CHECK_EQUAL(boost::math::erfc_inv(T(2)), -std::numeric_limits<T>::infinity());
      BOOST_CHECK_EQUAL(boost::math::erf_inv(T(1)), std::numeric_limits<T>::infinity());
      BOOST_CHECK_EQUAL(boost::math::erf_inv(T(-1)), -std::numeric_limits<T>::infinity());
      BOOST_CHECK_EQUAL(boost::math::erf_inv(T(0)), T(0));

      BOOST_CHECK_EQUAL(boost::math::erf(std::numeric_limits<T>::infinity()), T(1));
      BOOST_CHECK_EQUAL(boost::math::erf(-std::numeric_limits<T>::infinity()), T(-1));
      BOOST_CHECK_EQUAL(boost::math::erfc(std::numeric_limits<T>::infinity()), T(0));
      BOOST_CHECK_EQUAL(boost::math::erfc(-std::numeric_limits<T>::infinity()), T(2));
   }
   BOOST_CHECK_EQUAL(boost::math::erf(boost::math::tools::max_value<T>()), T(1));
   BOOST_CHECK_EQUAL(boost::math::erf(-boost::math::tools::max_value<T>()), T(-1));
   BOOST_CHECK_EQUAL(boost::math::erfc(boost::math::tools::max_value<T>()), T(0));
   BOOST_CHECK_EQUAL(boost::math::erfc(-boost::math::tools::max_value<T>()), T(2));
}

template <class T>
void test_spots(T, const char* t)
{
   std::cout << "Testing basic sanity checks for type " << t << std::endl;
   //
   // basic sanity checks, tolerance is 10 epsilon expressed as a percentage:
   //
   T tolerance = boost::math::tools::epsilon<T>() * 1000;
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(0.125)), static_cast<T>(0.85968379519866618260697055347837660181302041685015L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(0.5)), static_cast<T>(0.47950012218695346231725334610803547126354842424204L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(1)), static_cast<T>(0.15729920705028513065877936491739074070393300203370L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(5)), static_cast<T>(1.5374597944280348501883434853833788901180503147234e-12L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(-0.125)), static_cast<T>(1.1403162048013338173930294465216233981869795831498L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(-0.5)), static_cast<T>(1.5204998778130465376827466538919645287364515757580L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erfc(static_cast<T>(0)), static_cast<T>(1), tolerance);

   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(0.125)), static_cast<T>(0.14031620480133381739302944652162339818697958314985L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(0.5)), static_cast<T>(0.52049987781304653768274665389196452873645157575796L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(1)), static_cast<T>(0.84270079294971486934122063508260925929606699796630L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(5)), static_cast<T>(0.9999999999984625402055719651498116565146166211099L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(-0.125)), static_cast<T>(-0.14031620480133381739302944652162339818697958314985L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(-0.5)), static_cast<T>(-0.52049987781304653768274665389196452873645157575796L), tolerance);
   BOOST_CHECK_CLOSE(::boost::math::erf(static_cast<T>(0)), static_cast<T>(0), tolerance);

   tolerance = boost::math::tools::epsilon<T>() * 100 * 200; // 200 eps %.
#if defined(__CYGWIN__)
   // some platforms long double is only reliably accurate to double precision:
   if(sizeof(T) == sizeof(long double))
      tolerance = boost::math::tools::epsilon<double>() * 100 * 200; // 200 eps %.
#endif

   for(T i = -0.95f; i < 1; i += 0.125f)
   {
      T inv = boost::math::erf_inv(i);
      T b = boost::math::erf(inv);
      BOOST_CHECK_CLOSE(b, i, tolerance);
   }
   for(T j = 0.125f; j < 2; j += 0.125f)
   {
      T inv = boost::math::erfc_inv(j);
      T b = boost::math::erfc(inv);
      BOOST_CHECK_CLOSE(b, j, tolerance);
   }
}

