ComplexConverter.java

/**
 * Converts from steps and car type (petrol/diesel) to other information about journey
 * e.g. distance travelled, calories spent, co2 emissions saved
 * @author Sunshine Regiment
 */

package conversion;

public class ComplexConverter {

	private boolean diesel;//flag: true = diesel, false = petrol
	private int steps;//no units
	private double distance;//km
	private double fuel;//liter
	private double calories;//kcal
	private double co2;//gram
	private double treedays;//co2 absorbed by a tree in one day
	private BiometricProfile profile;//data about the person (age, height, weight, gender)
	
	/**
	 * Method for filling in attribute values
	 * 
	 * Extrapolates from known data (i.e. steps) to estimate values for distance, co2 saved, etc.
	 * Also acts as a wrapper for convertDiesel() and convertPetrol()
	 */
	public void convert() {
		//estimate the number of steps taken to travel 1 km, based on height & gender
		double steps_per_km = CalculateStep.step(profile);
		distance = steps/steps_per_km;
		
		//todo: find calories per step based on biometric data
		//0.044 calories per step on average
		calories = steps * Calories.calsPerStep(profile, steps_per_km);
		
		//based on engine type, the other calculations 
		if (diesel)
		{
			convertDiesel();
		}
		else{
			convertPetrol();
		}
	}
	
	/**
	 * Diesel-based conversion extension
	 * 
	 * Converts from distance in km to fuel required, co2 emissions prevented and tree-days saved
	 */
	private void convertDiesel(){
		//16.95km per liter for diesel engines, on average (cars manufactured in 2008)
		fuel = distance/16.95;
		//2.68 kg of co2 per liter of diesel => 2680g of co2 per liter of diesel
		co2 = fuel * 2680;
		//60g of co2 per tree per day
		treedays = co2/60;
	}
	
	/**
	 * Petrol-based conversion extension
	 * 
	 * Converts from distance in km to fuel required, co2 emissions prevented and tree-days saved
	 */
	private void convertPetrol(){
		//14.3km per liter for petrol engines, on average (cars manufactured in 2008)
		fuel = distance/14.3;
		//2.68 kg of co2 per liter of diesel => 2680g of co2 per liter of diesel
		co2 = fuel * 2680;
		//60g of co2 per tree per day
		treedays = co2/60;
	}
	
	
	/**
	 * Constructor for 'Converter'
	 * 
	 * Initialises values & runs 'convert()'
	 * 
	 * @param stepsTaken total steps taken
	 * @param dieselCar type of car engine (true = diesel, false = petrol)
	 */
	public ComplexConverter(int stepsTaken, BiometricProfile profile, boolean dieselCar) {
		steps = stepsTaken;
		this.profile = profile;
		diesel = dieselCar;
		convert();
	}

	/**
	 * Setter for 'steps'
	 * @param stepsTaken Number of steps taken
	 */
	public void set(int stepsTaken) {
		steps = stepsTaken;
		convert();
	}
	
	/**
	 * Getter for distance travelled
	 * @return Distance travelled (in km)
	 */
	public double getDistance() {
		return distance;
	}
	
	/**
	 * Getter for steps taken
	 * @return Steps taken
	 */
	public int getSteps() {
		return steps;
	}
	
	/**
	 * Getter for calories burnt
	 * @return Calories burnt (in kcal)
	 */
	public double getCalories() {
		return calories;
	}
	
	/**
	 * Getter for fuel saved
	 * @return Fuel saved (in litres)
	 */
	public double getFuel() {
		return fuel;
	}
	
	/**
	 * Getter for CO2 emissions prevented
	 * @return CO2 emissions prevented (in grams)
	 */
	public double getCO2() {
		return co2;
	}
	
	/**
	 * A tree captures ~60g of CO2 per day, so every 60g of emissions prevented is the
	 * equivalent of a tree absorbing CO2 for that day.
	 * @return Number of trees worth of CO2 reduction you've done today.
	 */
	public double getTreeDays() {
		return treedays;
	}
	
}