// ArduinoJson - https://arduinojson.org

// Copyright © 2014-2026, Benoit BLANCHON

// MIT License

#pragma once

#include <ArduinoJson/Configuration.hpp>

#include <ArduinoJson/Numbers/FloatTraits.hpp>

#include <ArduinoJson/Numbers/JsonFloat.hpp>

#include <ArduinoJson/Polyfills/math.hpp>

ARDUINOJSON_BEGIN_PRIVATE_NAMESPACE

struct FloatParts {

  uint32_t integral;

  uint32_t decimal;

  int16_t exponent;

  int8_t decimalPlaces;

};

template <typename TFloat>

inline int16_t normalize(TFloat& value) {

  using traits = FloatTraits<TFloat>;

  int16_t powersOf10 = 0;

  int8_t index = sizeof(TFloat) == 8 ? 8 : 5;

  int bit = 1 << index;

  if (value >= ARDUINOJSON_POSITIVE_EXPONENTIATION_THRESHOLD) {

    for (; index >= 0; index--) {

      if (value >= traits::positiveBinaryPowersOfTen()[uint8_t(index)]) {

        value *= traits::negativeBinaryPowersOfTen()[uint8_t(index)];

        powersOf10 = int16_t(powersOf10 + bit);

      }

      bit >>= 1;

    }

  }

  if (value > 0 && value <= ARDUINOJSON_NEGATIVE_EXPONENTIATION_THRESHOLD) {

    for (; index >= 0; index--) {

      if (value < traits::negativeBinaryPowersOfTen()[uint8_t(index)] * 10) {

        value *= traits::positiveBinaryPowersOfTen()[uint8_t(index)];

        powersOf10 = int16_t(powersOf10 - bit);

      }

      bit >>= 1;

    }

  }

  return powersOf10;

}

constexpr uint32_t pow10(int exponent) {

  return (exponent == 0) ? 1 : 10 * pow10(exponent - 1);

}

inline FloatParts decomposeFloat(JsonFloat value, int8_t decimalPlaces) {

  uint32_t maxDecimalPart = pow10(decimalPlaces);

  int16_t exponent = normalize(value);

  uint32_t integral = uint32_t(value);

  // reduce number of decimal places by the number of integral places

  for (uint32_t tmp = integral; tmp >= 10; tmp /= 10) {

    maxDecimalPart /= 10;

    decimalPlaces--;

  }

  JsonFloat remainder =

      (value - JsonFloat(integral)) * JsonFloat(maxDecimalPart);

  uint32_t decimal = uint32_t(remainder);

  remainder = remainder - JsonFloat(decimal);

  // rounding:

  // increment by 1 if remainder >= 0.5

  decimal += uint32_t(remainder * 2);

  if (decimal >= maxDecimalPart) {

    decimal = 0;

    integral++;

    if (exponent && integral >= 10) {

      exponent++;

      integral = 1;

    }

  }

  // remove trailing zeros

  while (decimal % 10 == 0 && decimalPlaces > 0) {

    decimal /= 10;

    decimalPlaces--;

  }

  return {integral, decimal, exponent, decimalPlaces};

}

ARDUINOJSON_END_PRIVATE_NAMESPACE