/*
This program converts a Fahrenheit temperature to Celsius.

Input:
    Fahrenheit temperature

Output:
    Fahrenheit temperature
    Celsius temperature

Example:
    Enter Fahrenheit temperature:
     100
    100.0° Fahrenheit is 37.8° Celsius

TODO:
    * All statements are currently global.
    * Functions will be added in a future release.

References:
    * http://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html
    * http://www.mathsisfun.com/temperature-conversion.html
*/

const TEMPERATURE_DIFFERENCE = 32;
const TEMPERATURE_RATIO = 5 / 9;

var fahrenheit = input("Enter Fahrenheit temperature:");

celsius = (fahrenheit - TEMPERATURE_DIFFERENCE) * TEMPERATURE_RATIO;

output(fahrenheit + "° Fahrenheit is " + celsius + "° Celsius");

function input(text) {
  if (typeof window === 'object') {
    return prompt(text)
  }
  else if (typeof console === 'object') {
    const rls = require('readline-sync');
    var value = rls.question(text);
    return value;
  }
  else {
    output(text);
    var isr = new java.io.InputStreamReader(java.lang.System.in); 
    var br = new java.io.BufferedReader(isr); 
    var line = br.readLine();
    return line.trim();
  }
}

function output(text) {
  if (typeof document === 'object') {
    document.write(text);
  } 
  else if (typeof console === 'object') {
    console.log(text);
  } 
  else {
    print(text);
  }
}