// Name : Matthew Reeves 
// This is a program to create an unsorted book list

//creates the UnsortedBookList class

public class UnsortedBookList
{
	//sets variables for the class	
	private final int DEFCAP=10;
	private Book List[];
	private int numElements;
	private int origCap;	

	//default constructor
	public UnsortedBookList()
	{
		List=new Book[DEFCAP];
		origCap=DEFCAP;
		numElements=0;
	}

	//constructor passed user inputted size variable throws
	//size out of range exception if size out of range
	public UnsortedBookList(int size) throws Exception
	{
		if (size>0)
		{
			List=new Book[size];
			origCap=size;
			numElements=0;
		}
		else
		{
			throw new Exception ("Error list size out of range");
		}
	}

	//method to add items to the list. Method enlarges array if needed
	public void addItem(Book theBook)
	{
		if (List.length==numElements)
		{
			enlarge();
		}
	
		List[numElements]=theBook;
		numElements++;	
	}
	
	//removes item if item is present in list
	public boolean removeItem(Book theBook)
	{
		int location=find(theBook);		

		if (location==-1)
		{
			return false;
		}
		else
		{
			List[location]=List[numElements-1];
			numElements--;
			return true;
		}		
	}
	
	//allows user to search list for a specific book
	public boolean findItem(Book theBook)
	{
		if (find(theBook)==-1)
		{
			return false;
		}
		else
		{
			return true;
		}
	}

	//checks if the list is empty
	public boolean isEmpty()
	{
		if (numElements<=0)
		{
			return true;
		}
		else 
		{
			return false;
		}
	}

	//checks and returns numElements
	public int lengthIs()
	{
		return numElements;
	}

	//builds and returns a formatted string to print the list to screen
	public String toString()
	{
		if (numElements<=0)
		{
			return String.format("***List is Empty***");
		}
		else
		{
			String tempString="";
		
			for(int count=0;count<numElements;count++)
			{
				tempString=tempString + String.format("%s\n",List[count].toString());
			}
			
			return String.format("%s", tempString);
		}
	}

	//clears the list
	public void clear()
	{
		numElements=0;

		if (List.length>origCap)
		{
			Book newList[];
			newList=new Book[origCap];
			List=newList;
		}			
	}

	//allows the program to dynamically expand the size of the list array
	private void enlarge()
	{
		Book larger[];
		larger=new Book[List.length+origCap];
		
		for (int count=0; count<numElements; count++)
		{
			larger[count]=List[count];
		}
		
		List=larger;
	}

	//method that searches the list for a specific book
	private int find(Book theBook)
	{
		for (int count=0 ; count<numElements;count++)
		{
			if (List[count].equals(theBook)==true)
			{
				return count;
			}
		}
		return -1;
	}

}