text: /*
   * MIT License
   *
   * Copyright (c) 2021 Joey Castillo
   *
   * 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.
   */
  
  #ifndef _WATCH_UTILITY_H_INCLUDED
  #define _WATCH_UTILITY_H_INCLUDED
  ////< @file watch_utility.h
  
  #include "watch.h"
  
  /** @addtogroup utility Utility Functions
    * @brief This section covers various useful functions that don't fit anywhere else.
    **/
  /// @{
  /** @brief Returns a two-letter weekday for the given timestamp, suitable for display
    *        in positions 0-1 of the watch face
    * @param date_time The watch_date_time whose weekday you want.
    */
  const char * watch_utility_get_weekday(watch_date_time date_time);
  
  /** @brief Returns the UNIX time (seconds since 1970) for a given date/time in UTC.
    * @param date_time The watch_date_time that you wish to convert.
    * @param year The year of the date you wish to convert.
    * @param month The month of the date you wish to convert.
    * @param day The day of the date you wish to convert.
    * @param hour The hour of the date you wish to convert.
    * @param minute The minute of the date you wish to convert.
    * @param second The second of the date you wish to convert.
    * @param utc_offset The number of seconds that date_time is offset from UTC, or 0 if the time is UTC.
    * @return A UNIX timestamp for the given date/time and UTC offset.
    * @note Implemented by Wesley Ellis (tahnok) and based on BSD-licensed code by Josh Haberman:
    *       https://blog.reverberate.org/2020/05/12/optimizing-date-algorithms.html
    */
  uint32_t watch_utility_convert_to_unix_time(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second, uint32_t utc_offset);
  
  /** @brief Returns the UNIX time (seconds since 1970) for a given watch_date_time struct.
    * @param date_time The watch_date_time that you wish to convert.
    * @param utc_offset The number of seconds that date_time is offset from UTC, or 0 if the time is UTC.
    * @return A UNIX timestamp for the given watch_date_time and UTC offset.
    */
  uint32_t watch_utility_date_time_to_unix_time(watch_date_time date_time, uint32_t utc_offset);
  
  /** @brief Returns the UNIX time (seconds since 1970) for a given watch_date_time struct.
    * @param timestamp The UNIX timestamp that you wish to convert.
    * @param utc_offset The number of seconds that you wish date_time to be offset from UTC.
    * @return A watch_date_time for the given UNIX timestamp and UTC offset, or if outside the range that
    *         watch_date_time can represent, a watch_date_time with all fields set to 0.
    * @note Adapted from MIT-licensed code from musl, Copyright © 2005-2014 Rich Felker, et al.:
    *       https://github.com/esmil/musl/blob/1cc81f5cb0df2b66a795ff0c26d7bbc4d16e13c6/src/time/__secs_to_tm.c
    */
  watch_date_time watch_utility_date_time_from_unix_time(uint32_t timestamp, uint32_t utc_offset);
  
  /** @brief Converts a time from a given time zone to another time zone.
    * @param date_time The watch_date_time that you wish to convert
    * @param origin_utc_offset The number of seconds from UTC in the origin time zone
    * @param destination_utc_offset The number of seconds from UTC in the destination time zone
    * @return A watch_date_time for the given UNIX timestamp and UTC offset, or if outside the range that
    *         watch_date_time can represent, a watch_date_time with all fields set to 0.
    * @note Adapted from MIT-licensed code from musl, Copyright © 2005-2014 Rich Felker, et al.:
    *       https://github.com/esmil/musl/blob/1cc81f5cb0df2b66a795ff0c26d7bbc4d16e13c6/src/time/__secs_to_tm.c
    */
  watch_date_time watch_utility_date_time_convert_zone(watch_date_time date_time, uint32_t origin_utc_offset, uint32_t destination_utc_offset);
  
  /** @brief Returns a temperature in degrees Celsius for a given thermistor voltage divider circuit.
    * @param value The raw analog reading from the thermistor pin (0-65535)
    * @param highside True if the thermistor is connected to VCC and the series resistor is connected
    *                 to GND; false if the thermistor is connected to GND and the series resistor is
    *                 connected to VCC.
    * @param b_coefficient From your thermistor's data sheet, the B25/85 coefficient. A typical value
    *                      will be between 2000 and 5000.
    * @param nominal_temperature From your thermistor's data sheet, the temperature (in Celsius) at
    *                            which the thermistor's resistance is at its nominal value.
    * @param nominal_resistance The thermistor's resistance at the nominal temperature.
    * @param series_resistance The value of the other resistor in the voltage divider.
    * @note Ported from Adafruit's MIT-licensed CircuitPython thermistor code, (c) 2017 Scott Shawcroft:
    *       https://github.com/adafruit/Adafruit_CircuitPython_Thermistor/blob/main/adafruit_thermistor.py
    */
  float watch_utility_thermistor_temperature(uint16_t value, bool highside, float b_coefficient, float nominal_temperature, float nominal_resistance, float series_resistance);
  
  #endif
  