package questions;

import java.util.Collection;
import java.util.List;
import course.Test;

/**
 * An abstract representation of
 * a bank of questions stored for the user.
 * It has a list of questions in it.
 */
public abstract class QuestionBank
{
	Collection<Question> questions;
	public QuestionBank() {
   }

   /**
 	Adds a new question into the question bank.
 	@param question The question to be added to the question bank.

  	  pre:
	  // There is no record in the Collection that is exactly the same as
	  // the question to be added.
	  //
	  (!questions.contains(q))
	  	&&
	  // The question is not empty.
	  (q.getText() != null) && (q.getText().length() > 0)
		&&
	  // The answer is not empty.
	  (q.getAnswer() != null) && (q.getAnswer().length() > 0)
		&&
 	  // The time and difficulty are not empty.
 	  (q.getTime() != 0) && (q.getDifficulty() != 0);

	  post:
	  // A record is in the output data if and only if it is the
	  // new record to be added or if it is in the input data.
	  //
	  (questions'.contains(q))
	*/
	public abstract void addQuestion(Question q);

   /**
 	Edits a question in the question bank.
 	@param question The question to be edited.

  	  pre:
	  // The given question is in this.questions.
	  //
	  questions.contains(q);

	*/
	public abstract void editQuestion(Question q);

	/**
 	 Deletes a question from the question bank.
 	 @param question The question to be removed from the question bank.

	  pre:
	  // The given question is in this.questions.
	  //
	  questions.contains(q);

	  post:
	  // A record is in the output data if and only if it is not the
	  // existing record to be deleted and it is in the input data.
	  // The questions database size must be one smaller than before
	 (!questions'.contains(q)) && (questions'.size() == questions.size()-1);
 	*/
	public abstract void removeQuestion(Question q);

	public abstract List<Question> getQuestions();

	/**
 	Finds question(s) in the question bank.
 	@param question The target question to search for in the bank.

     post:
	  // The questions in the return list must match the query
	  //
	  forall(Question q ; return.contains(q);
	  	q.questionText.contains(query) || q.answer.toString().contains(query));
 	*/
	public abstract List<Question> search(String query);

}