com.lyncode.jtwig.functions.internal.generic.Last Maven / Gradle / Ivy

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/**
 * Copyright 2012 Lyncode
 *
 * 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 com.lyncode.jtwig.functions.internal.generic;

import com.lyncode.jtwig.functions.Function;
import com.lyncode.jtwig.functions.exceptions.FunctionException;
import com.lyncode.jtwig.functions.util.ObjectIterator;

import java.util.Iterator;
import java.util.Map;

import static com.lyncode.jtwig.functions.util.Requirements.requires;
import static org.hamcrest.CoreMatchers.equalTo;

public class Last implements Function {

    @Override
    public Object execute(Object... arguments) throws FunctionException {
        requires(arguments)
                .withNumberOfArguments(equalTo(1));

        if ((arguments[0] instanceof Iterable) || arguments[0].getClass().isArray()) {
            ObjectIterator objectIterator = new ObjectIterator(arguments[0]);
            Object current = null;
            while (objectIterator.hasNext())
                current = objectIterator.next();
            return current;
        }
        else if (arguments[0] instanceof Map) {
            Iterator iterator = ((Map) arguments[0]).keySet().iterator();
            Object current = null;
            while (iterator.hasNext())
                current = iterator.next();
            if (current == null)
                return null;
            else
                return (((Map) arguments[0]).get(current));
        }
        else if (arguments[0] instanceof String) {
            String argument = (String) arguments[0];
            if (argument.isEmpty()) return null;
            return argument.charAt(argument.length() - 1);
        }
        else return arguments[0];
    }
}