package edu.wit.cs.comp1050;

import java.util.Scanner;

/**
 *  PA3b linear equation solver.
 * @author caushie
 *  02/15/2019
 */
public class PA3b {

    /**
     * Error to display if the command-line arguments are invalid
     */
    public static final String ERR_USAGE = "Please supply 6 numbers (a-f).";

    /**
     * Error to display if the equation has no solution
     */
    public static final String ERR_NOSLTN = "The equation has no solution.";

    /**
     * Number of required parameters (a-f)
     */
    public static final int NUM_PARAMS = 6;

    /**
     * Validates command-line arguments and returns parameters if valid
     *
     * @param args command-line arguments
     * @return if valid an array of parameters, else null
     */
    public static double[] validateArgs(String[] args) {
        if (args.length < 6)
            return null;

        double[] myArr = new double[args.length];

        boolean isValid = false;

        for (int i = 0; i < args.length; ++i) {
            try {
                myArr[i] = Double.parseDouble(args[i]);
            } catch (NumberFormatException nfe) {
                return null;
            }

        }
        return myArr;
    }

    /**
     * Uses command-line arguments to create an instance of the linear equation, and
     * reports the outcome
     *
     * @param args command-line arguments, interpreted as equation parameters
     */
    public static void main(String[] args) {


//We call validate args to validate our  input and then do the according operations with the linear equation provided.
        if (validateArgs(args) != null) {
            LinearEquation equation = new LinearEquation(validateArgs(args));

            if (equation.isSolvable()) {
                System.out.printf("Solution: x=%.3f, y=%.3f%n", equation.getX(),equation.getY());
            }
            else {
                System.out.println(ERR_NOSLTN);
            }
        }else {
            System.out.println(ERR_USAGE);
            System.exit(0);
        }



    }

}