br.com.objectos.html.io.ValueList Maven / Gradle / Ivy

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/*
 * Copyright 2016 Objectos, Fábrica de Software LTDA.
 *
 * 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 br.com.objectos.html.io;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 * @author [email protected] (Marcio Endo)
 */
abstract class ValueList {

  private static final ValueList EMPTY = new Empty();

  private ValueList() {
  }

  public static ValueList empty() {
    return EMPTY;
  }

  public abstract ValueList add(SingleValue value);

  public abstract void consume(HtmlReader reader);

  private static class Empty extends ValueList {

    @Override
    public ValueList add(SingleValue value) {
      return new One(value);
    }

    @Override
    public void consume(HtmlReader reader) {
      // noop
    }

  }

  private static class One extends ValueList {

    private final Value value;

    public One(Value value) {
      this.value = value;
    }

    @Override
    public ValueList add(SingleValue value) {
      return new Many(this.value, value);
    }

    @Override
    public void consume(HtmlReader reader) {
      value.consume(reader);
    }

  }

  private static class Many extends ValueList {

    private final List> list = new ArrayList<>(4);

    public Many(Value first, SingleValue second) {
      list.add(first);
      list.add(second);
    }

    @Override
    public ValueList add(SingleValue value) {
      list.add(value);
      return this;
    }

    @Override
    public void consume(HtmlReader reader) {
      List> remaining = new ArrayList<>(list);
      List> temp = new ArrayList<>(remaining.size());
      Iterator iterator = reader.iterator();
      while (iterator.hasNext()) {
        TagPojo tag = iterator.next();
        for (Value value : remaining) {
          value.consumeTag(tag);
          value.removeNextIteration(temp);
        }

        remaining.removeAll(temp);
        temp.clear();
        if (remaining.isEmpty()) {
          break;
        }
      }
    }

  }

}