// The MIT License (MIT)
//
// Copyright (c) 2018 Mateusz Pusz
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
// !!! Before you commit any changes to this file please make sure to check if it !!!
// !!! renders correctly in the documentation "Examples" section.                 !!!
// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

#include <mp-units/compat_macros.h>
#include <mp-units/ext/format.h>
#ifdef MP_UNITS_IMPORT_STD
import std;
#else
#include <iostream>
#include <optional>
#endif
#ifdef MP_UNITS_MODULES
import mp_units;
#else
#include <mp-units/systems/isq.h>
#include <mp-units/systems/si.h>
#endif

using namespace mp_units;

// real voltage range
inline constexpr int min_voltage = -10;
inline constexpr int max_voltage = 10;
inline constexpr int voltage_range = max_voltage - min_voltage;

// hardware encoding of voltage
using voltage_hw_t = std::uint16_t;
inline constexpr voltage_hw_t voltage_hw_error = std::numeric_limits<voltage_hw_t>::max();
inline constexpr voltage_hw_t voltage_hw_min = 0;
inline constexpr voltage_hw_t voltage_hw_max = voltage_hw_error - 1;
inline constexpr voltage_hw_t voltage_hw_range = voltage_hw_max - voltage_hw_min;
inline constexpr voltage_hw_t voltage_hw_zero = voltage_hw_range / 2;


// clang-format off
inline constexpr struct hw_voltage_origin final :
  relative_point_origin<point<si::volt>(min_voltage)> {} hw_voltage_origin;

inline constexpr struct hw_voltage_unit final :
  named_unit<"hwV", mag_ratio<voltage_range, voltage_hw_range> * si::volt, hw_voltage_origin> {} hw_voltage_unit;

using hw_voltage_quantity_point = quantity_point<hw_voltage_unit, hw_voltage_origin, voltage_hw_t>;
// clang-format on

// mapped HW register
volatile voltage_hw_t hw_voltage_value;

std::optional<hw_voltage_quantity_point> read_hw_voltage()
{
  voltage_hw_t local_copy = hw_voltage_value;
  if (local_copy == voltage_hw_error) return std::nullopt;
  return point<hw_voltage_unit>(local_copy);
}

void print(QuantityPoint auto qp)
{
  std::cout << MP_UNITS_STD_FMT::format("{:10} ({:5})", qp.quantity_from_zero(),
                                        value_cast<double, si::volt>(qp).quantity_from_zero());
}

int main()
{
  // simulate reading of 3 values from the hardware
  hw_voltage_value = voltage_hw_min;
  quantity_point qp1 = read_hw_voltage().value();
  hw_voltage_value = voltage_hw_zero;
  quantity_point qp2 = read_hw_voltage().value();
  hw_voltage_value = voltage_hw_max;
  quantity_point qp3 = read_hw_voltage().value();

  print(qp1);
  print(qp2);
  print(qp3);
}