// BlankConsoleLab.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>

using namespace std;

float tempCelsius, windCelsius;
float tempFahrenheit, windFahrenheit;
float windSpeed;

// Constants for the range of acceptable temperatures and wind speed.

const float minF = -80.0, maxF = 121.0;
const float minC = -62.0, maxC = 49.5;
const float minW = 0, maxW = 231;

float ConvertTemperature(float temperature, char initialSystem) {

    // If initialSystem is 'C', temperature is converted into fahrenheit. If initialSystem is 'F', temperature is converted into celsius.

    float convertedTemp;

    switch(initialSystem) {

    case 'C':
        // Converting celsius to fahrenheit, return the result.

        convertedTemp = (temperature * 1.8) + 32.0;
        return convertedTemp;

    case 'F':
        // Converting fahrenheit to celsius, return the result.

        convertedTemp = (temperature - 32.0) / 1.8;
        return convertedTemp;
    }

}

bool CheckWindSpeed(float& input) {

    // Checks to see if the value entered is between the minimum and maximum wind speeds.

    if (input < minW || input > maxW) {

        cout << "\nInvalid wind speed. Please enter a number between 0 and 231" << endl;
        return false; // Returns false if the value is beyond or below the range.

    }
    else return true;

}

float GetWindChill() {

    // Simply calculates the wind chill in fahrenheit, and converts it to celsius using a previous function

    float windChill;

    windChill = 35.74 + (0.6215 * tempFahrenheit) + (pow(windSpeed, 0.16) * ((0.4275 * tempFahrenheit) - 35.75));
    
    return windChill; // Returns the wind chill based on what the user entered before the function has been called. Only outputs as fahrenheit.

}

int main()
{
    char choice = 'Y';

    while (choice == 'Y') {

        cout << "Please enter a temperature between -80 to 121 degrees fahrenheit, or -62 and 49.5 degrees celsius." << endl;
        cout << "Example entries: -32.3 F, 27.8 C\n" << endl;

        float tempInput;
        char tempSystem;

        bool validEntries = false;

        // Taking input from the user until they give a valid entry.
        // A valid entry should be a number and the character C for celsius or F for fahrenheit.

        do {

            cin >> tempInput >> tempSystem;

            if (tempSystem == 'C') {

                if (tempInput < minC || tempInput > maxC) {

                    cout << "\nTemperature in celsius must be between -62 and 49.5 degrees. Please try again." << endl;

                }
                else {
                    validEntries = true;
                    tempCelsius = tempInput;
                    tempFahrenheit = ConvertTemperature(tempInput, 'C');
                }

            }
            else if (tempSystem == 'F') {

                if (tempInput < minF || tempInput > maxF) {

                    cout << "\nTemperature in fahrenheit must be between -80 and 121 degrees. Please try again." << endl;

                }
                else {
                    validEntries = true;
                    tempFahrenheit = tempInput;
                    tempCelsius = ConvertTemperature(tempInput, 'F');
                }

            }
            else {

                cout << "\nInvalid temperature system. Please try again with C or F as your unit." << endl;

            }

        } while (validEntries == false);

        cout << "\nNext, enter a wind speed between 0 and 231mph. You do not need to include a unit." << endl;

        // validEntries is just a boolean that's getting reused.

        validEntries = false;

        do {

            cin >> windSpeed;

            validEntries = CheckWindSpeed(windSpeed); // If the user's input is between the minium and maximum wind speeds, this will return true.

        } while (validEntries == false);

        // Setting the wind chill values.

        windFahrenheit = GetWindChill();
        windCelsius = ConvertTemperature(windFahrenheit, 'F');

        int colWidth = 20;

        cout << "\nConversions for " << tempInput << tempSystem << " with wind speed " << windSpeed << "MPH." << endl;

        // Printing the table.

        cout << setprecision(2) << fixed << left << setw(20);
        cout << setw(colWidth) << "\nCelsius" << setw(colWidth) << "Fahrenheit" << setw(colWidth) << "Wind Speed" << setw(colWidth) << "Wind Chill (F)" << setw(colWidth) << "Wind Chill (C)" << endl;
        cout << setw(colWidth) << tempCelsius << setw(colWidth) << tempFahrenheit << setw(colWidth) << windSpeed << setw(colWidth) << windFahrenheit << setw(colWidth) << windCelsius << endl;

        cout << "\nIf you would like to input another set of data, please enter 'Y'" << endl;
        cin >> choice;

    }

    return 0;

}