public class Car {
    // instance variables
    private String carMake, carModel, carColor, carSetOwner, currentOwner, hasCatalytic;
    private int carYearModel, carNumOfDoors, carCylinderCapacity, carMilesPerGallon, carInitialPrice, carPurchasePrice, noOfOwner;
    private boolean carHasCatalytic;

    /**
     * Constructor for objects of class Car
     */
    public Car(String make, String model, int yearModel, String color, int numOfDoors, int cylinderCapacity,  int milesPerGallon, int initialPrice, boolean hasCatalytic) {
        // initialise instance variables
        carMake = make;
        carModel = model;
        carYearModel = yearModel;
        carColor = color;
        noOfOwner = 0;
        if (numOfDoors > 1) {
            carNumOfDoors = numOfDoors;
        } else {
            System.out.println("Invalid number of doors!");
        }
        if (cylinderCapacity > 0) {
            carCylinderCapacity = cylinderCapacity;
        } else {
            System.out.println("Invalid amount for cylinder capacity!");
        }
        if (milesPerGallon > 0) {
            carMilesPerGallon = milesPerGallon;
        } else {
            System.out.println("Invalid amount for mile per gallon!");
        }
        if (initialPrice >= 0) {
            carInitialPrice = initialPrice;
        } else {
            System.out.println("Initial price cannot be less than 0!");
        }
        carHasCatalytic = hasCatalytic;
        checkCarConverter();
    }

    //an accessor method that returns a string (Car's make)
    public String getMake() {
        return carMake;
    }

    //an accessor method that returns a string (Car's model)
    public String getModel() {
        return carModel;
    }

    /**
     * A void method that opens a message box containing car's details depending on whether it has been ever been sold or not.
     * It also has an if then else statement which is used to translate boolean's value into a string to be used in the messge box
     */
    public void printDetails() {
        if (carHasCatalytic == true) {
            hasCatalytic = "does";
        } else {
            hasCatalytic = "does not";
        }

        if (noOfOwner == 0) {
            System.out.println("This vehicle is a " + carColor + " " + carCylinderCapacity + "cc " + carMake + " " + carModel + " " + carYearModel + " model with " + carNumOfDoors +
            " doors. It has not been sold once yet. It does " + carMilesPerGallon + " miles per gallon and " + hasCatalytic + " have a catalytic converter. The original purchase price is £" + carInitialPrice
            + ".");
        } else if(noOfOwner > 0) {
        System.out.println("This vehicle is a " + carColor + " " + carCylinderCapacity + "cc " + carMake + " " + carModel + " " + carYearModel + " model with " + carNumOfDoors +
            " doors. It has had " + noOfOwner + " owner(s) and its present owner is " + currentOwner
            + ". It does " + carMilesPerGallon + " miles per gallon and " + hasCatalytic + " have a catalytic converter. The original purchase price was £" + carInitialPrice
            + " and the price is now £" + carPurchasePrice + ".");
        }
    }

    //a mutator method used to set the price of the car prior to selling it
    public void setPurchasePrice(int purchasePrice) {
        carPurchasePrice = purchasePrice;
    }

    //a mutator method used to set the name of the owner who is going to buy the vehicle
    public void setOwner(String ownerName) {
        carSetOwner = ownerName;
    }

    //a void method that sells the car. It increases the number of owners by 1 and sets the current owner of the vehicle
    public void sell() {
        noOfOwner += 1;
        currentOwner = carSetOwner;
    }

    //a mutator method that takes a boolean as an input and configures vehicle's catalytic converter
    public void goingCleaner(boolean putCatalyticConverter) {
        if (putCatalyticConverter == true) {
            carHasCatalytic = true;
        } else {
            carHasCatalytic = false;
        }
    }

    //a void method that checks if the vehicle is fitted with a catalytic converter and prompts a message depending on it
    public void checkCarConverter() {
        if (carHasCatalytic == true) {
            System.out.println ("Be aware your car could be less polluting");
        } else {
            System.out.println ("This car is better for the enviroment");
        }
    }
}