/*
 * peripherals_button.hpp
 *
 *  Created on: Apr 17, 2021
 *      Author: erki
 */

#ifndef SKULLC_PERIPHERALS_BUTTON_HPP_
#define SKULLC_PERIPHERALS_BUTTON_HPP_

#include <cstdint>

namespace Peripherals
{

enum class ButtonPress : std::uint32_t
{
  NOT_PRESSED,
  SHORT_PRESS,
  LONG_PRESS
};

/**
 * A class to abstract a button!
 *
 * Usage example:
 * @code
 * int a = 4;
 * @endcode
 *
 * @tparam G The class to use for GPIO. Must have members @c set(bool).
 * @tparam H The HAL class to use.
 */
template<typename G, typename H>
class Button
{
public:
  using gpio = G;
  using hal = H;

  gpio sw; ///< A switch instance.

  static constexpr std::uint32_t TIMEOUT_SHORT_PRESS = 50;
  static constexpr std::uint32_t TIMEOUT_LONG_PRESS = 500;

  Button() = delete;
  explicit Button(const gpio& sw)
      : sw(sw)
  {}

  /**
   * Does the do.
   */
  void update()
  {
    const bool is_pressed = sw.read();
    ButtonPress new_state = ButtonPress::NOT_PRESSED;

    if (is_pressed && !was_pressed_)
    {
      time_pressed_down_ = hal::getMillis();
    } else if (!is_pressed && was_pressed_)
    {
      const std::uint32_t time_held = hal::getMillis() - time_pressed_down_;
      if (time_held > TIMEOUT_LONG_PRESS)
        new_state = ButtonPress::LONG_PRESS;
      else if (time_held > TIMEOUT_SHORT_PRESS)
        new_state = ButtonPress::SHORT_PRESS;

      time_pressed_down_ = 0;
    }

    was_pressed_ = is_pressed;
    current_state_ = new_state;
  }

  [[nodiscard]] ButtonPress getState() const
  {
    return current_state_;
  }

private:
  bool was_pressed_ = false;
  std::uint32_t time_pressed_down_ = 0;
  ButtonPress current_state_ = ButtonPress::NOT_PRESSED;
};

}// namespace Peripherals

#endif /* SKULLC_PERIPHERALS_BUTTON_HPP_ */