/*
 * Copyright 2002-2013 the original author or authors.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */
package org.springframework.data.gemfire.function;

import com.gemstone.gemfire.cache.execute.FunctionContext;

/**
 * @author David Turanski
 * @author John Blum
 * @since 1.3.0
 */
class DefaultFunctionArgumentResolver implements FunctionArgumentResolver {

	private static final Object[] EMPTY_ARRAY = new Object[0];

	/* (non-Javadoc)
	 * @see org.springframework.data.gemfire.function.FunctionArgumentResolver#resolveFunctionArguments(com.gemstone.gemfire.cache.execute.FunctionContext)
	 */
	@Override
	public Object[] resolveFunctionArguments(final FunctionContext functionContext) {
		return (isArray(functionContext.getArguments())) ? toObjectArray((Object[]) functionContext.getArguments())
			: getArguments(functionContext);
	}

	private boolean isArray(final Object value) {
		return (value != null && value.getClass().isArray());
	}

	private Object[] toObjectArray(final Object[] arguments) {
		Object[] result = new Object[arguments.length];
		System.arraycopy(arguments, 0, result, 0, arguments.length);
		return result;
	}

	private Object[] getArguments(final FunctionContext context) {
		Object arguments = context.getArguments();
		return (arguments != null ? new Object[] { arguments } : EMPTY_ARRAY);
	}

}
