namespace DriversLicenseExam_CalebFontenot
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void exitButton_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void openFileButton_Click(object sender, EventArgs e)
        {
            // Create variables
            string[] correctAnswers = new string[20],
                     studentAnswers = new string[20];
            bool[] correctAnswerCompare = new bool[20];
            // Read the file with the correct answers.
            correctAnswers = readFiles("correctAnswers.txt");
            // Now read the file with the student answers.
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                studentAnswers = readFiles(openFileDialog1.FileName);
            }
            
            if (correctAnswers != null & studentAnswers != null)
            {
                for (int i = 0; i < correctAnswers.Length; i++)
                {
                    if (correctAnswers[i] == studentAnswers[i])
                    {
                        correctAnswerCompare[i] = true;
                    }
                    else
                    {
                        correctAnswerCompare[i] = false;
                    }
                }
                // Count up the correct answers
                int numCorrect = 0;
                for (int i = 0; i < correctAnswerCompare.Length; i++)
                {
                    if (correctAnswerCompare[i] == true)
                    {
                        numCorrect++;
                    }
                }
                correctAnswersLabel.Text = numCorrect.ToString() + "/20";
                double gradePercentage = (numCorrect / 20.0);
                feedbackLabel.Text = "You scored a " + gradePercentage.ToString("P");
            } else
            {
                MessageBox.Show("Unable to open file(s).");
            }

        }

            private string[] readFiles(string fileName)
            {
                try
                {
                    // Create StreamReader to read the correct answers.
                    StreamReader inputFile = File.OpenText(fileName);

                    string[] returnStringArray = new string[20];

                    int i = 0;
                    while (!inputFile.EndOfStream)
                    {
                        returnStringArray[i] = inputFile.ReadLine();
                        i++;
                    }
                    inputFile.Close();

                    return returnStringArray;
                } catch
                {
                    return null;
                }
            }
        }
    }