/*
 * Copyright 2015 Laurent Pellegrino
 *
 * 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.yfiton.api.parameter.converters;

import com.google.common.collect.ImmutableList;

import java.util.List;
import java.util.stream.Stream;

/**
 * @author lpellegr
 */
public final class ListStringConverter implements Converter<List<String>> {

    @Override
    public List<String> convert(String parameterName, String parameterValue) {
        if (parameterValue.isEmpty()) {
            return ImmutableList.of();
        }

        char[] chars = parameterValue.toCharArray();

        ImmutableList.Builder<String> builder = ImmutableList.builder();

        StringBuilder buffer = new StringBuilder();
        
        for (int i = 0; i < chars.length; i++) {
            char c = chars[i];

            if (c == ',') {
                builder.add(buffer.toString());
                buffer.setLength(0);
            } else {
                buffer.append(c);
            }

            if (i == chars.length - 1) {
                if (c == ',') {
                    buffer.setLength(0);
                }

                builder.add(buffer.toString());
            }
        }

        return builder.build();
    }

}


