#include <cstdint>

#include <Dio.h>
#include <mcal_reg_access.h>

namespace
{
  inline std::uint32_t port_mode_register        (const std::uint32_t port) { return std::uint32_t(port + 0x00UL); }
  inline std::uint32_t output_type_register      (const std::uint32_t port) { return std::uint32_t(port + 0x04UL); }
  inline std::uint32_t output_speed_register     (const std::uint32_t port) { return std::uint32_t(port + 0x08UL); }
  inline std::uint32_t pull_up_pull_down_register(const std::uint32_t port) { return std::uint32_t(port + 0x0CUL); }
  inline std::uint32_t input_data_register       (const std::uint32_t port) { return std::uint32_t(port + 0x10UL); }
  inline std::uint32_t output_data_register      (const std::uint32_t port) { return std::uint32_t(port + 0x14UL); }

  void set_direction_output(const std::uint32_t port, const std::uint32_t bpos)
  {
    // Set the port pin control bits.

    // Set for no pull up, no pull down.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::reg_and(pull_up_pull_down_register(port),
                                                      ~static_cast<std::uint32_t>(UINT32_C(0x03) << (bpos * 2U)));

    // Select the fastest output speed.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::reg_or(output_speed_register(port),
                                                     static_cast<std::uint32_t>(UINT32_C(0x03) << (bpos * 2U)));

    // Set the port pin to push-pull output type.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::bit_clr(output_type_register(port), bpos);

    // Set the port pin direction to digital output.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::reg_or(port_mode_register(port),
                                                     static_cast<std::uint32_t>(UINT32_C(0x01) << (bpos * 2U)));
  }

  #if 0
  void set_direction_input(const std::uint32_t port, const std::uint32_t bpos)
  {
    // Set the port pin direction to digital input.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::reg_and(port_mode_register(port),
                                                      ~static_cast<std::uint32_t>(UINT32_C(0x03) << (bpos * 2U)));
  }
  #endif

  void set_pin_high(const std::uint32_t port, const std::uint32_t bpos)
  {
    // Set the port output value to high.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::bit_set(output_data_register(port), bpos);
  }

  void set_pin_low(const std::uint32_t port, const std::uint32_t bpos)
  {
    // Set the port output value to low.
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint32_t>::bit_clr(output_data_register(port), bpos);
  }

  bool read_input_value(const std::uint32_t port, const std::uint32_t bpos)
  {
    // Read the port input value.

    // According to the microcontroller handbook:
    // "These bits are read-only and can be accessed in *word* mode only, ..."
    // We, therefore, access this register with a 16-bit address-type
    // template parameter.

    return
    mcal::reg::dynamic_access<std::uint32_t,
                              std::uint16_t>::bit_get(input_data_register(port), bpos);
  }
}

extern "C"
void Dio_Init(const Dio_ConfigType*)
{
  set_direction_output(mcal::reg::gpioa_base, 5U);
  set_direction_output(mcal::reg::gpioc_base, 8U);
}

extern "C"
void Dio_WriteChannel(Dio_ChannelType ChannelId, Dio_LevelType Level)
{
  (Level != STD_LOW ? set_pin_high(mcal::reg::gpioa_base + std::uint32_t((ChannelId >> 8U) * 0x0400U), ChannelId & 0xFU)
                    : set_pin_low (mcal::reg::gpioa_base + std::uint32_t((ChannelId >> 8U) * 0x0400U), ChannelId & 0xFU));
}

extern "C"
Dio_LevelType Dio_ReadChannel(Dio_ChannelType ChannelId)
{
  const bool pin_is_high =
    read_input_value(mcal::reg::gpioa_base + std::uint32_t((ChannelId >> 8U) * 0x0400U), ChannelId & 0xFU);

  return (pin_is_high ? STD_HIGH : STD_LOW);
}