/*
 * Written By  : Ahmad Jawed ZAFAR
 * Date        : 12/08/2009
 * Web Site    : www.yashlar.net
 * Description : In This Program You First Register Exams from Text Files (Maximum of 10 Exams, You Can Increase Them)
 *	       : and Store Them, then the User Can Enter Any Registered Exam And Answer Them. Each Question must be In A New Line Inside The .txt File.
 * 	       : The Answers Are Stored In A Text File Named "Answer" Followed By The Test Name.
 * Important   : You Must Place The Test Files In A Folder Together With The Program. 			 
 * */

import java.util.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;

public class Exam  // Main Class
{
	private String[][] questions; // stores questions
	private String[][] answers; // stores user answers

	int testNum; // counts the number of test read from files
	int numQ, numA; // counts the number of questions and answers belong to a specific test.
	private String testList[]; // stores the names of the tests read from files.
	private int[] questionNum; // stores the number of questions of test respectively
	private int numAnsweredTest; // counts the number of test answered by the user
	private int[] answeredTestOrder; // stores the answered tests respectively
	
	public Exam()
	{ // initializing variables.
		questionNum = new int[100];
		testList = new String[10];
		questions = new String[10][100];
		answers = new String[10][100]; 
		numQ = numA = 0;
		testNum = 0;
		numAnsweredTest = 0;
		answeredTestOrder = new int[10];
	}
	
///-----------------------------------------------------------------------------------	
	
	public boolean isAlreadyAnswered(int testNum) // checks if a test is already answered
	{
		for (int i=0; i<numAnsweredTest; i++)
		{
			if (testNum == answeredTestOrder[i]) // checks if the user already answered a test and try to answer again
			{
				return true;
			}
		}
		return false;
	}
	
///-----------------------------------------------------------------------------------	
	
	public void readTest() // reads a test from the file
	{
		String question, testN;
		Scanner scnr = new Scanner(System.in);
		
		System.out.println("Enter Test Name");
		testList[testNum] = scnr.nextLine().toUpperCase();
		System.out.println("Enter Test File Name");
		testN = scnr.nextLine();
		
		testN = testN + ".txt"; // concatenates ".txt" extensions to files. (user is not supposed to enter the files name with extension)
		try
		{
			BufferedReader ques = new BufferedReader(new FileReader(testN));

			while ((question = ques.readLine()) != null)
			{
				question = question.toUpperCase();
				
				questions[testNum][numQ] = question; // read every questions from the test line by line and store them in questions array.
				numQ++;
			}
			questionNum[testNum] = numQ; // stores the number of questions belong to current test
			numQ = 0;
			testNum++; // increments number of tests //
			System.out.println("Test Name : " + testList[testNum-1] + " Registered Successfully");
			System.out.println("++++++++++++++++++++++++++++++++++++++++++++++++++++");
		}
		catch (IOException e) // when user enter an invalid test file name.
		{
			System.out.println("File Name Not Fount");		
		}	
	}

///-----------------------------------------------------------------------------------
	public void testList() // shows the list of available tests
	{
		if (testNum == 0) // if there is not any test registered
		{
			System.out.println("Test List Is Empty, Register A Test First");
		}
		else
		{
			for (int i=0; i<testNum; i++)
			{
				System.out.println(i+1 + " : Course Name : " + testList[i] + ", Number Of Questions : " + questionNum[i]);
			}
		}
	}
	
///-----------------------------------------------------------------------------------
	
	public void checkAnswers() // user can see his/her answers.
	{
		if (numAnsweredTest == 0) // if user did not answered any test yet
		{
			System.out.println("You Havent Answered Any Test Yet");
		}
		else
		{
			System.out.println("Your Answers Are As Follow");
			System.out.println("--------------------------");
			for (int i=0; i<numAnsweredTest; i++)
			{
				System.out.println("Answered Questions From Test " + testList[answeredTestOrder[i]]);
				System.out.println("=====================================");
				for (int j=0; j<questionNum[answeredTestOrder[i]]; j++)
				{
					System.out.println(j+1 + " : " + questions[answeredTestOrder[i]][j]);
					System.out.println(answers[answeredTestOrder[i]][j]);
					System.out.println("*******************************");
				}
			}
		}
	}
	
///-----------------------------------------------------------------------------------
	
	public boolean AnswerTest() // user answer a test
	{
		Scanner scnr = new Scanner(System.in);

		if (testNum == 0) // checks if there is any test registered and checks if test number is correct 
		{
			System.out.println("There Is Not Any Test Registered Yet");
		}
		else
		{	
			System.out.println("Following Tests Are Available");
			System.out.println("-----------------------------");
			testList();
			
			String testNumber;
			System.out.println("Enter The Test Number You Want To Enter");
			testNumber = scnr.nextLine();
			int testNtmp = (Integer.parseInt(testNumber)) - (1);
			answeredTestOrder[numAnsweredTest] = testNtmp;
			
			if (isAlreadyAnswered(testNtmp) == true) // calls the functions isAlreadyAnswered() to ensure user did not answered this test yet.
			{
				System.out.println("You Have Already Answered This Test");
				return true;
			}
			if (testNtmp > testNum) // if user enter an invalid test number (if user tries to enter test number 4 while there are only 3 tests available)
			{
				System.out.println("Invalid Test Number");
			}
			else
			{
				String ansFile;
				ansFile = testList[testNtmp] + "Answer.txt";
			
				try
				{
					BufferedWriter testAns = new BufferedWriter(new FileWriter(ansFile));
					System.out.println("Welcome To " + testList[testNtmp] + " Test, Answer The Following Questions");
					System.out.println("--------------------------------------------------------------------------\n");
					
					for (int i=0; i<questionNum[testNtmp]; i++)
					{
						System.out.println(i+1 + " : " + questions[testNtmp][i] + " ?");
						answers[testNtmp][i] = scnr.nextLine().toUpperCase();
						System.out.println("---------------------------------------------------");
					
						testAns.append(answers[testNtmp][i]); // stores the user answers in a text files
						testAns.newLine();
					}	
					testAns.close();
					numAnsweredTest++; // increments the number of answered tests.
				}
				catch (IOException e)
				{
					System.out.println("File Cant Be Created");		
				}
			
				System.out.println("============================");
				System.out.println("Test Completed Successfully");
				System.out.println("============================\n");
			}
		}
		return true;
		
	}
	
///-----------------------------------------------------------------------------------
	
	public void mainMenue() // list of options, user can select
	{
		System.out.println();
		System.out.println("         Select A Task ");
		System.out.println("|-----------------------------|");
		System.out.println("|1: Register A Test        (R)|");
		System.out.println("|2: Enter A Test           (E)|");
		System.out.println("|3: View Your Answers      (V)|");
		System.out.println("|3: Exit From The Program  (X)|");
		System.out.println("|-----------------------------|\n");
	}
	
///-----------------------------------------------------------------------------------
	
	public static void main(String[] args) // the main function
	{
		Exam ex = new Exam(); // creats an object of class Exam
		
		String testName = "";
		Scanner scnr = new Scanner(System.in);
		String slct;
		
		
		System.out.println("************************ Welcome ************************");
		
		ex.mainMenue();
		slct = scnr.nextLine();
		
		while (!slct.equalsIgnoreCase("x"))
		{
			if (slct.equalsIgnoreCase("r"))
			{
				ex.readTest();
				ex.mainMenue();
			}
			else if (slct.equalsIgnoreCase("e"))
			{
				ex.AnswerTest();
				ex.mainMenue();
			}
			else if (slct.equalsIgnoreCase("m"))
			{
				ex.mainMenue();
			}
			else if (slct.equalsIgnoreCase("v"))
			{
				ex.checkAnswers();
			}
			else
			{
				System.out.println("Invalid Selection. Enter (M) To Go To The Main Menue");
			}
			System.out.println("Select A Task");
			slct = scnr.next();
		}

		System.out.println("Bye Bye !");
	
	}

}