package eg.edu.alexu.csd.datastructure.linkedList.cs2cs16;

import java.util.Scanner;

public class PolynomialSolver implements IPolynomialSolver {

    DLinkedList A, B, C, R;

    public void sort(int[][] arr)
    {
        int n = arr.length;
        for (int i = n - 2; i >= 0; i--) {

            int keyCoef = arr[i][0];
            int keyExp = arr[i][1];

            int j = i + 1;

            while (j < n && arr[j][1] > keyCoef) {

                arr[j - 1][0] = arr[j][0];
                arr[j - 1][1] = arr[j][1];
                j = j + 1;
            }
            arr[j - 1][1] = keyCoef;
            arr[j - 1][1] = keyExp;
        }
    }

    public DLinkedList choose (char poly) {

        DLinkedList n = new DLinkedList();
        if (poly == 'A') {

            A = new DLinkedList();
            n = A;
        }
        else if (poly == 'B') {

            B = new DLinkedList();
            n = B;
        }
        else if (poly == 'C') {

            C = new DLinkedList();
            n = C;
        }
        return n;
    }

    public void setPolynomial(char poly, int[][] terms) {

        DLinkedList n = choose(poly);
        for (int i = 0; i < terms.length; i++) {

            n.add(terms[i]);
        }
    }

    public String print(char poly) {

        DLinkedListNode n = choose(poly).head;
        String ans = "";
        int[] tmp = new int[2];
        while (n != null) {

            tmp = (int[])n.value;
            if (tmp[0] == 0) {

                continue;
            }
            else {

                ans = ans + Integer.toString(tmp[0]);
                if (tmp[1] == 1) {

                    ans = ans + 'x';
                }
                else {

                    ans = ans + 'x' + '^' + tmp[1];
                }
            }
            n = n.next;
        }
        return ans;
    }

    public void clearPolynomial(char poly) {

    }

    public float evaluatePolynomial(char poly, float value) {
        return 0;
    }

    public int[][] add(char poly1, char poly2) {
        return new int[0][];
    }

    public int[][] subtract(char poly1, char poly2) {
        return new int[0][];
    }

    public int[][] multiply(char poly1, char poly2) {
        return new int[0][];
    }

    public static void main(String[] args) {

        PolynomialSolver polynomialSolver = new PolynomialSolver();

        while (true) {

            System.out.println("Please choose an action");
            System.out.println("-----------------------");
            System.out.println("1- Set a polynomial variable");
            System.out.println("2- Print the value of a polynomial variable");
            System.out.println("3- Add two polynomials");
            System.out.println("4- Subtract two polynomials");
            System.out.println("5- Multiply two polynomials");
            System.out.println("6- Evaluate a polynomial at some point");
            System.out.println("7- Clear a polynomial variable");

            Scanner input = new Scanner(System.in).useDelimiter("\n");
            int action = input.nextInt();
            char variableName;

            if (action == 1) {

                do {

                    System.out.println("Insert the variable name: A, B or C");
                    variableName = input.next().charAt(0);
                } while (variableName != 'A' && variableName != 'B' && variableName != 'C');

                System.out.println("Insert the polynomial terms in the form:");
                System.out.println("(coeff1, exponent1), (coeff2, exponent2), ..");
                String line = input.next();

                int counter = 0;
                for (int i = 0, len = line.length(); i < len; i++) {

                    if (line.charAt(i) == '(') {

                        counter++;
                    }
                }

                int[][] terms = new int[counter][2];
                int k = 0, len = line.length();
                for (int i = 0; i < counter; i++) {
                    for (int j = 0; j < 2; j++) {
                        for (; k < len; k++) {
                            if (Character.isDigit(line.charAt(k))) {

                                terms[i][j] = Character.getNumericValue(line.charAt(k));
                                k++;
                                break;
                            }
                        }
                    }
                }
                polynomialSolver.sort(terms);

                polynomialSolver.setPolynomial(variableName, terms);
            }

            if (action == 2) {

                do {

                    System.out.println("Insert the variable name: A, B or C");
                    variableName = input.next(".").charAt(0);
                } while (variableName != 'A' && variableName != 'B' && variableName != 'C');

                System.out.println(polynomialSolver.print(variableName));
            }

        }

    }
}