/*
* Part of exercises for lecture 2.
*
* NOTICE: If you set the field DEBUG to true, the class
* will print a lot of helptext when running.
*/

 

public class RasmusVector{
	private static final boolean DEBUG = false;
	private int size = 0;
	private int capacityIncrement = 2;
	private int initialSize = 3;
	private Object[] elements;
	
	private void debugPrint( String msg ){
		if( DEBUG ){
			System.out.println( "DEBUG: " + msg );
		}
	}
	private void debugPrintMethod( String msg ){
		if( DEBUG ){
			System.out.println( "DEBUG: -------------------------" );	
			System.out.println( "DEBUG: " + msg + " was called" );	
			System.out.println( "DEBUG: -------------------------" );	
		}
	}

	RasmusVector(){
		debugPrintMethod( "RasmusVector()" );
		elements = new Object[ initialSize ];
	}
	
	public int capacity(){
		debugPrintMethod( "capacity()" );
		debugPrint( "returns " + elements.length );
		return elements.length;
	}
	
	public int size(){
		debugPrintMethod( "size()" );
		debugPrint( "returns " + size );
		return size;
	}
	
	public void add( Object element ){
		debugPrintMethod( "add(Object element)" );
		debugPrint( "elements.length < (size+1) = "+elements.length+"<"+(size+1)+" = "+(elements.length<(size+1)) );
		if( elements.length < (size+1) ){
			Object[] newArray = new Object[ elements.length + capacityIncrement ];
			debugPrint( "newArray created with the size " + (elements.length + capacityIncrement) );
			for( int n = 0; n < elements.length; n++ ){
				debugPrint( "sets newArray["+n+"] = elements["+n+"]" );
				newArray[n] = elements[n];
			}
			debugPrint( "sets elements = newArray" );
			elements = newArray;
		}
		debugPrint( "sets elements["+size+"] = element" );
		elements[size] = element;
		size = size +1;		
		debugPrint( "sets size = size+1 (that is. size is now " + size + ")" );
	}
	
	public Object get( int index ){
		debugPrintMethod( "get(int index)" );
		if( index < 0 ){
			debugPrint( "index was negative (=" + index + "), so we return null" );
			return null;
		}
		else if( index >= size ){
			debugPrint( "index (=" + index + ") was not found (size=" + size + "), so we return null" );
			return null;
		}
		else{
			debugPrint( "We return the element at index " + index );
			return elements[index];
		}
	}
	
	public Object remove( int index ){
		debugPrintMethod( "remove(int index)" );
		if( index < 0 ){
			debugPrint( "index was negative (=" + index + "), so we return null without removing anything" );
			return null;
		}
		else if( index >= size ){
			debugPrint( "index (=" + index + ") was not found (size=" + size + "), so we return null without removing anything" );
			return null;
		}
		else{
			debugPrint( "we same the element to be deleted in the variable removedObject" );
			Object removedObject = elements[index];
			for( int n = index; n < size-1; n++){
				debugPrint( "we sets elements["+n+"] = elements["+(n+1)+"]" );
				elements[n] = elements[n+1];
			}
			size = size - 1;
			debugPrint( "We set size = size -1 (so now size is " + size + ")" );

			if( elements.length > ( size + ( 2*capacityIncrement ) ) && elements.length > 2 * capacityIncrement ){
				debugPrint( "elements is too big for the elements we store - so we shrink it" );
				Object[] newArray = new Object[ elements.length - capacityIncrement ];
				debugPrint( "newArray is made with the size " + newArray.length );
				for( int n = 0; n < size; n++ ){
					debugPrint( "sets  newArray["+n+"] = elements["+n+"]" );
					newArray[n] = elements[n];
				}
				debugPrint( "sets elements = newArray" );
				elements = newArray;
			}

			debugPrint( "we return the deleted object" );
			return removedObject;
		}
	}

	public String toString(){
		String s = "RasmusVector[";
		for( int n = 0; n < size(); n++ ){
			s += get( n ).toString();
			if( n != (size()-1) ) s+= ", ";
		}	
		return s + "]";
	}


}