questionCatalog.java

import java.util.Random;
import java.util.ArrayList;
import java.io.*;



/*

	#############
	question catalog class
	#############
	
	
	
	FUNCTION NAME					DESCRIPTION
	###CONSTRUCTOR###
	questionCatalog(String filename)			constructor with file name
	###CATALOG FUNCTIONS###
	setMode(String mode)				set mode (random/ordered)
	setEndless(boolean bool)				set/unset endless mode
	nextQuestion()					return next question ID
	###DATASET FUNCTIONS###
	getSize()						write number of entries
	printCatalog()						write out question catalog
	getCatalogName()					retrieves the catalog name
	getCatalogDesc()					...the catalog description
	getCatalogAuthor()					...the catalog author's name
	getCatalogDate()					...the creation date
	getCatalogLimit()					...the catalog's time limit
	###RANDOM MODE FUNCTIONS###
	remove(int id)						remove entry from access index
	printRandomIndex()					write out access index
	###DEBUG FUNCTIONS###
	countChars(String s, char c)				counts the occurrences of a char in a string
	debugMsg(String msg)				write debug message

*/



public class questionCatalog
/* question catalog class */
{

	//variables
	private int numbQuestions;				//number of questions
	private int questionAnswered;			//number of answered questions
	private String catalogName;				//name of catalog
	private String catalogDescription;			//description of catalog
	private String catalogAuthor;			//catalog author
	private String catalogDate;				//creation date of catalog
	private int catalogLimit;				//time limit in minutes
	public question questions[];				//question array
	private boolean modeEndless;			//endless mode enabled?
	private String catalogMode = "random";		//mode (random/ordered)
	
	//access declarations
	ArrayList<Integer> elementList = new ArrayList<Integer>();	//access index
	Random randomGenerator = new Random();				//random generator
	int thisQuestion=-1;								//question ID (ordered mode)
	
	
	
	questionCatalog(String filename)
	/* constructor with file name */
	{
		
		//try loading catalog
		try
		{
			
			//deklarations
			/*FileReader fileStream = new FileReader(filename);
			BufferedReader targetFile = new BufferedReader(fileStream);*/
			BufferedReader targetFile = new BufferedReader(new InputStreamReader(new FileInputStream(filename), "UTF-8"));
			this.debugMsg("About to open file: " + filename);
				
				//get catalog meta information
				numbQuestions = Integer.parseInt(targetFile.readLine());
				debugMsg("Read number of questions: " + numbQuestions);
				catalogName = targetFile.readLine();
				debugMsg("Read catalog name: " + catalogName);
				catalogDescription = targetFile.readLine();
				debugMsg("Read catalog description: " + catalogDescription);
				catalogAuthor = targetFile.readLine();
				debugMsg("Read catalog author: " + catalogAuthor);
				catalogDate = targetFile.readLine();
				debugMsg("Read catalog date: " + catalogDate);
				catalogLimit = Integer.parseInt(targetFile.readLine());
				debugMsg("Read catalog time limit: " + catalogLimit);
				
				//save questions and answers in array
				
					//write debug message
					debugMsg("About to read " + numbQuestions + " questions from catalog file: " + filename);
					
					//(temporary) variable deklarations
					this.questions = new question[numbQuestions];
					//question questions[] = new question[numbQuestions];
					int qType;
					String qText = new String("");
					String qHint = new String("");
					String qExplanation = new String("");
					String qAnswers[] = new String[5];
					String temp = new String("");
					
					//read values in loop
					for(int i=0;i<numbQuestions;i++)
					{
						//read question and type
						qText = targetFile.readLine();
						debugMsg("qText: " + qText);
						qType = Integer.parseInt(targetFile.readLine());
						debugMsg("qType: " + qType);
						
						//read information based on type
						if(qType == 0)
						{
							//only one answer - define next line as answer and write debug message
							qAnswers[0] = targetFile.readLine();
							qHint = targetFile.readLine();
							qExplanation = targetFile.readLine();
							debugMsg("Read answer: '" + qAnswers[0] + "'");
							debugMsg("Read hint: '" + qHint + "'");
							debugMsg("Read explanation: '" + qExplanation + "'");
							
							//create object and return initial values
							questions[i] = new question(qText, qType, qHint, qExplanation);
							questions[i].addAnswer(qAnswers[0]);
						}
						else
						{
							//multiple answers - read next 5 lines as answers
							qAnswers[0] = targetFile.readLine();
							qAnswers[1] = targetFile.readLine();
							qAnswers[2] = targetFile.readLine();
							qAnswers[3] = targetFile.readLine();
							qAnswers[4] = targetFile.readLine();
							
							//read correct answers
							temp = targetFile.readLine();
							
							if(countChars(temp, ',') > 0)
							{
								//multiple answers exist
								String qCorrectAnswers[] = new String[countChars(temp, ',')+1];
								qCorrectAnswers = temp.split("\\,");
								
								//read hint and explanation
								qHint = targetFile.readLine();
								debugMsg("Read hint: '" + qHint + "'");
								qExplanation = targetFile.readLine();
								debugMsg("Read explanation: '" + qExplanation + "'");
								
								//create object and return initial values
								questions[i] = new question(qText, qType, qHint, qExplanation);
								
								//define correct answers
								for(int ii=0;ii<5;ii++) { questions[i].addAnswer(qAnswers[ii]); }
								for(int ii=0;ii<qCorrectAnswers.length;ii++) { questions[i].setCorrect(Integer.parseInt(qCorrectAnswers[ii])); }
							}
							else
							{
								//one answer exists
								String qCorrectAnswers[] = new String[1];
								qCorrectAnswers[0] = temp;
								
								//read hint and explanation
								qHint = targetFile.readLine();
								debugMsg("Read hint: '" + qHint + "'");
								qExplanation = targetFile.readLine();
								debugMsg("Read explanation: '" + qExplanation + "'");
								
								//create object and return initial values
								questions[i] = new question(qText, qType, qHint, qExplanation);
								
								//define correct answers
								for(int ii=0;ii<5;ii++) { questions[i].addAnswer(qAnswers[ii]); }
								questions[i].setCorrect(Integer.parseInt(temp));
								
							}

						}
						
					}
				
				//close file
				targetFile.close();
				debugMsg("Closed file");
				
				//create access index
				for(int i=0;i<this.questions.length;i++)
				{
					this.elementList.add(i);
					debugMsg("Added " + i + " to random index.");
				}
		
		}
		catch(java.io.IOException exp)
		{
			//write error message
			debugMsg("Error while opening file " + filename);
			debugMsg("Stack trace:");
			exp.printStackTrace();	
		}
		
	}
	
	public void setMode(String mode)
	/* set mode (random/ordered) */
	{
		//set mode based on string
		if(mode.equals("ordered")) { this.catalogMode = "ordered"; }
		else { this.catalogMode = "random"; }
	}
	
	public void setEndless(boolean bool)
	/* set/unset endless mode */
	{
		//set flag based on param
		this.modeEndless = bool;
	}
	
	private static int countChars(String s, char c)
	/* counts the occurrences of a char in a string */
	{
		return s.replaceAll("[^" + c + "]", "").length();
	}
	
	private void debugMsg(String msg)
	/* write debug message */
	{
		//write message
		System.out.println("QC: " + msg);
	}
	
	public int getSize()
	/* write number of entries */
	{
		return this.questions.length;
	}
	
	public void printCatalog()
	/* write out question catalog */
	{
		for(int i=0;i<this.questions.length;i++)
		{
			debugMsg("Question #" + i + ", " + (i+1) + "/" + this.questions.length);
			this.questions[i].printQuestionData();			
		}
	}
	
	//function for getting catalog meta information
	public String getCatalogName() { return this.catalogName; }
	public String getCatalogDesc() { return this.catalogDescription; }
	public String getCatalogAuthor() { return this.catalogAuthor; }
	public String getCatalogDate() { return this.catalogDate; }
	public int getCatalogLimit() { return this.catalogLimit; }

	private void remove(int id)
	/* remove entry from access index */
	{
		for(int i=0;i<this.elementList.size();i++)
		{
			if(elementList.get(i) == id) { this.elementList.remove(i); }
		}
	}
	
	public void printRandomIndex()
	/* write out access index */
	{
		//write out access index if entries found
		if(this.elementList.size() > 0)
		{
			for(int i=0;i<this.elementList.size();i++)
			{
				debugMsg("RI: #" + i + " ==> " + elementList.get(i));
			}
		}
		else
		{
			//no entries
			debugMsg("RI: EMPTY");
		}
	}
	
	public int nextQuestion()
	/* return next question ID */
	{
		//get next question ID based on mode
		if(this.catalogMode.equals("ordered"))
		{
			//ordered mode --> was this the last question?
			if((this.thisQuestion+1) == this.questions.length)
			{
				//Yes - restart or abort (based on mode)
				if(this.modeEndless == true)
				{
					debugMsg("Ordered mode, last question, endless mode - will continue from beginning");
					thisQuestion=0;
					return 0;
				}
				else
				{
					debugMsg("Ordered mode, last question, NO endless mode - will end right now");
					return -1;
				}
			}
			else
			{
				//No - increase counter and return value
				debugMsg("Ordered mode, remaining questions, will continue with next question");
				thisQuestion++;
				return thisQuestion;
			}
			
		}
		else
		{
			//random mode --> get next possible random ID and remove entry from array
			//TODO: repeat
			if(this.elementList.size() >= 1 || this.modeEndless == true)
			{
				int temp = this.elementList.get(randomGenerator.nextInt(this.elementList.size()));
				debugMsg("Random mode, remaining questions, will continue with question #" + temp);
				if(this.modeEndless == false) { this.remove(temp); }
				return temp;
			}
			else
			{
				//no questions remaining --> return error
				debugMsg("Random mode, once, NO remaining questions, will stop right now");
				return -1;
			}
		}
	}
	
}