flutter-buddy-website/lib/helpers/json.dart

// Functions related to parsing JSON strings and objects.

import '/var/config.dart';
import 'package:flutter/material.dart';
import 'dart:math';

String formatOpenWeatherData(var data) {
  String location = pullOpenWeatherCity(data),
      temp = pullOpenWeatherTemp(data),
      conditions = pullOpenWeatherConditions(data),
      windSpeed = pullOpenWeatherWind(data),
      humidity = pullOpenWeatherHumidity(data);

  String windChill = getWindChill(temp, windSpeed),
      heatIndex = getHeatIndex(temp, humidity),
      windAnnoyance = getWindAnnoyance(temp, windSpeed),
      feelsLike = getUniversalThermalClimateIndex();

  String comfort = "";

  String text =
      "$location is $temp$tempUnits and $conditions"
      " with a wind speed of $windSpeed$windUnits"
      " and humidity of $humidity$humidityUnits."
      " $windChill"
      " $heatIndex"
      " $windAnnoyance"
      " $feelsLike"
      " $comfort";

  final String doubleSpace = "  ", singleSpace = " ";
  while (text.contains(doubleSpace)) {
    text = text.replaceAll(doubleSpace, singleSpace);
  }

  return text;
}

String pullOpenWeatherCity(var data) {
  String location = "${data['city']['name']} (${data['city']['country']})";
  if (debug) {
    debugPrint("DEBUG: location = '$location'");
  }
  return location;
}

String pullOpenWeatherTemp(var data) {
  String temp = data['list'][0]['main']['temp'].toString();
  if (debug) {
    debugPrint("DEBUG: temp = '$temp'");
  }
  return temp;
}

String pullOpenWeatherConditions(var data) {
  String conditions = data['list'][0]['weather'][0]['description'].toString();
  if (debug) {
    debugPrint("DEBUG: conditions = '$conditions'");
  }
  return conditions;
}

String pullOpenWeatherWind(var data) {
  String wind = data['list'][0]['wind']['speed'].toString();
  if (debug) {
    debugPrint("DEBUG: wind = '$wind'");
  }
  return wind;
}

String pullOpenWeatherHumidity(var data) {
  String humidity = data['list'][0]['main']['humidity'].toString();
  if (debug) {
    debugPrint("DEBUG: humidity = '$humidity'");
  }
  return humidity;
}

double calcWindChill(double temp, double windSpeed) {
  // ## Wind Chill ##
  // # Wind speed as noted in: https://answers.yahoo.com/question/index?qid=20091020183148AAHm3kB&guccounter=1
  // # More official source: https://www.weather.gov/media/epz/wxcalc/windChill.pdf
  double windChill =
      35.74 +
      (0.6215 * temp) -
      (35.75 * pow(windSpeed, 0.16)) +
      (0.4275 * temp * pow(windSpeed, 0.16));
  if (debug) {
    debugPrint("DEBUG: windChill = '$windChill'");
  }
  return windChill;
}

String getWindChill(String temp, String windSpeed) {
  double temperature = double.parse(temp);
  double wind = double.parse(windSpeed);

  if ((temperature < 50 && wind > 5) || debug) {
    double windChill = calcWindChill((temperature), (wind));
    return "My guess is that's a wind chill of $windChill$tempUnits.";
  }
  return "";
}

double calcHeatIndex(double temp, double humidity) {
  // ## Heat Index ##
  // # Official formula: https://www.wpc.ncep.noaa.gov/html/heatindex_equation.shtml
  double heatIndex =
      -42.379 +
      2.04901523 * temp +
      10.14333127 * humidity -
      0.22475541 * temp * humidity -
      0.00683783 * temp * temp -
      0.05481717 * humidity * humidity +
      0.00122874 * temp * temp * humidity +
      0.00085282 * temp * humidity * humidity -
      0.00000199 * temp * temp * humidity * humidity;

  if (humidity < 13 && temp >= 80 && temp <= 112) {
    heatIndex -= ((13 - humidity) / 4) * sqrt((17 - (temp - 95.0).abs()) / 17);
  }

  if (humidity > 85 && temp >= 80 && temp <= 87) {
    heatIndex += ((humidity - 85) / 10) * ((87 - temp) / 5);
  }

  if (heatIndex < 80) {
    heatIndex =
        0.5 * (temp + 61.0 + ((temp - 68.0) * 1.2) + (humidity * 0.094));
    heatIndex = (heatIndex + temp) / 2;
  }

  if (debug) {
    debugPrint("DEBUG: heatIndex = '$heatIndex'");
  }
  return heatIndex;
}

String getHeatIndex(String temp, String humidity) {
  double temperature = double.parse(temp);
  double humid = double.parse(humidity);

  if (temperature > 80 || debug) {
    double heatIndex = calcHeatIndex((temperature), (humid));
    return "My guess is that's a heat index of $heatIndex$tempUnits.";
  }
  return "";
}

double calcWindAnnoyance(double temp, double windSpeed) {
  double windAnnoyance = (temp / (windSpeed * (windSpeed * 0.05)));

  if (debug) {
    debugPrint("DEBUG: windAnnoyance = '$windAnnoyance'");
  }
  return windAnnoyance;
}

String getWindAnnoyance(String temp, String windSpeed) {
  double temperature = double.parse(temp);
  double wind = double.parse(windSpeed);

  double windAnnoyance = calcWindAnnoyance(temperature, wind);

  if (windAnnoyance < 3) {
    return "Wind may be a bit much for the temperature.";
  }
  return "";
}

double calcUniversalThermalClimateIndex() {
  return 0;
}

String getUniversalThermalClimateIndex() {
  return "";
}