/**
 * The MIT License
 * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package com.iluwatar.pipeline;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Stage handler that returns a new instance of String without the alphabet characters of the input string.
 */
class RemoveAlphabetsHandler implements Handler<String, String> {

  private final Logger logger = LoggerFactory.getLogger(RemoveAlphabetsHandler.class);

  @Override
  public String process(String input) {
    StringBuilder inputWithoutAlphabets = new StringBuilder();

    for (int index = 0; index < input.length(); index++) {
      char currentCharacter = input.charAt(index);
      if (Character.isAlphabetic(currentCharacter)) {
        continue;
      }

      inputWithoutAlphabets.append(currentCharacter);
    }

    String inputWithoutAlphabetsStr = inputWithoutAlphabets.toString();
    logger.info(String.format("Current handler: %s, input is %s of type %s, output is %s, of type %s",
        RemoveAlphabetsHandler.class, input, String.class, inputWithoutAlphabetsStr, String.class));

    return inputWithoutAlphabetsStr;
  }
}