package com.example.mathtrainer;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    TextView numberOneText, numberTwoText, equationText;
    EditText enterSolution;
    boolean rightAnswer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setViews();
        setSum();
    }

    public void setViews() {
        numberOneText = findViewById(R.id.numberOne);
        numberTwoText = findViewById(R.id.numberTwo);
        equationText = findViewById(R.id.equation);
        enterSolution = findViewById(R.id.enterSolution);
    }

    private void setSum() {
        int firstNumber = getRandomNumber(1, 10);
        int secondNumber = getRandomNumber(1, 10);
        String equationSymbol = getEquationSymbol();

        if (firstNumber < secondNumber) {
            numberOneText.setText(String.format(getString(R.string.numberOne), String.valueOf(secondNumber)));
            numberTwoText.setText(String.format(getString(R.string.numberTwo), String.valueOf(firstNumber)));
            equationText.setText(equationSymbol);
        } else {
            numberOneText.setText(String.format(getString(R.string.numberOne), String.valueOf(firstNumber)));
            numberTwoText.setText(String.format(getString(R.string.numberTwo), String.valueOf(secondNumber)));
            equationText.setText(equationSymbol);
        }
    }

    public String getEquationSymbol() {

        int rand = getRandomNumber(1, 3);

        if (rand == 1) {
            return "+";
        } else if (rand == 2) {
            return "-";
        } else {
            return "*";
        }
    }

    private int getRandomNumber(int lower, int higher) {
        return (int) (Math.random() * higher + lower);
    }

    private int getCorrectSolution(int firstNumber, int secondNumber, String mathSymbol) {
        if (mathSymbol.equals("+")) {
            return firstNumber + secondNumber;

        } else if (mathSymbol.equals("-")) {
            return firstNumber - secondNumber;

        } else {
            return firstNumber * secondNumber;
        }
    }

    public void newSum(View view) {
        if (rightAnswer) {
            setSum();
            enterSolution.setBackgroundColor(Color.WHITE);
            rightAnswer = false;
            enterSolution.setText("");
        } else {
            Toast.makeText(this, "Enter a solution first!", Toast.LENGTH_SHORT).show();
        }
    }

    public void checkAnswer(View view) {

        try {
            int input = Integer.parseInt(enterSolution.getText().toString());
            int firstNumber = Integer.parseInt(numberOneText.getText().toString());
            int secondNUmber = Integer.parseInt(numberTwoText.getText().toString());
            String mathSymbol = equationText.getText().toString();
            int correctAnswer = getCorrectSolution(firstNumber, secondNUmber, mathSymbol);

            if (correctAnswer == input) {
                enterSolution.setBackgroundColor(Color.GREEN);
                Toast.makeText(this, "Correct!", Toast.LENGTH_SHORT).show();
                rightAnswer = true;
            } else {
                enterSolution.setBackgroundColor(Color.RED);
                Toast.makeText(this, "Wrong!", Toast.LENGTH_SHORT).show();
            }
        } catch (NumberFormatException nfe) {
            Toast.makeText(this, "Input an answer first!", Toast.LENGTH_SHORT).show();
        }
    }
}