package org.litesoft.commonfoundation.typeutils;

import java.util.*;

@SuppressWarnings("Convert2Diamond")
public class Sets
{
    public static <T> HashSet<T> newHashSet()
    {
        return new HashSet<T>();
    }

    public static <T> HashSet<T> newHashSet( int zInitialSize )
    {
        return new HashSet<T>( Math.max( 1, zInitialSize ) );
    }

    @SuppressWarnings("unchecked")
    public static <T> HashSet<T> newHashSet( T... pInitialEntries )
    {
        HashSet<T> zSet = newHashSet();
        add( zSet, pInitialEntries );
        return zSet;
    }

    public static <T> Set<T> empty()
    {
        return Collections.emptySet();
    }

    public static <T> Set<T> copy( Set<T> pSet )
    {
        Set<T> zCopy = newHashSet();
        zCopy.addAll( deNull( pSet ) );
        return zCopy;
    }

    @SuppressWarnings("unchecked")
    public static <T> void add( Set<T> pSet, T... pToAdd )
    {
        if ( pToAdd != null )
        {
            for ( T zT : pToAdd )
            {
                if ( zT != null )
                {
                    pSet.add( zT );
                }
            }
        }
    }

    public static <T> Set<T> deNull( Set<T> pToCheck )
    {
        if ( pToCheck == null )
        {
            pToCheck = empty();
        }
        return pToCheck;
    }

    public static boolean isNullOrEmpty( Set<?> pToCheck )
    {
        return (pToCheck == null || pToCheck.isEmpty());
    }

    public static boolean isNotNullOrEmpty( Set<?> pToCheck )
    {
        return (pToCheck != null && !pToCheck.isEmpty());
    }

    public static void assertNotNullNotEmpty( String pErrorMessage, Set<?> pToAssert )
            throws IllegalArgumentException
    {
        if ( isNullOrEmpty( pToAssert ) )
        {
            Strings.errorNullOrEmpty( pErrorMessage, "Collection" );
        }
    }
}