#include <assert.h>
#include "list.h"

IntList::IntList()
    : size( 0 )
    , cursor( 0 )
{}

bool IntList::isEmpty()
{
    return getSize() == 0;
}

bool IntList::isFull()
{
    return getSize() == MAX_LIST_LENGTH;
}

int IntList::getSize()
{
    assert( size >= 0 && size <= MAX_LIST_LENGTH );
    return size;
}

void IntList::start()
{
    cursor = 0;
}

void IntList::advance()
{
    assert( !atEnd() );
    cursor++;
}

bool IntList::atEnd()
{
    return cursor >= size;
}

int IntList::getData()
{
    assert( cursor >= 0 && cursor < size );
    return items[ cursor ];
}

void IntList::insertBefore( int item )
{
    if( isEmpty() ) {
        placeAtStart( item );
    } else {
        assert( cursor >= 0 && cursor < size );
        makeRoom( cursor );
        items[ cursor ] = item;
    }
}

void IntList::insertAfter( int item )
{
    if( isEmpty() ) {
        placeAtStart( item );
    } else {
        assert( cursor >= 0 && cursor < size );
        makeRoom( cursor + 1 );
        items[ cursor + 1 ] = item;
        ++cursor;
    }
}

void IntList::deleteItem()
{
    assert( cursor >= 0 && cursor < size );
    for( int idx = cursor; idx < size; idx++ ) {
        items[ idx ] = items[ idx + 1 ];
    }
    --size;
}

void IntList::makeRoom( int position )
{
    assert( !isFull() );
    for( int idx = size - 1; idx >= position; --idx ) {
        items[ idx + 1 ] = items[ idx ];
    }
    ++size;
}

void IntList::placeAtStart( int item )
{
    cursor = 0;
    items[ 0 ] = item;
    size = 1;
}