objectos.way.HttpCookiesParser Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of objectos.way Show documentation
Objectos Way allows you to build web applications using only Java.
There is a newer version: 0.1.11
/*
 * Copyright (C) 2023 Objectos 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 objectos.way;

import java.util.HashMap;
import java.util.Map;

final class HttpCookiesParser {

  private final Map cookies = new HashMap<>();

  private HttpRequestCookiesValue currentValue;

  private int index;

  private final StringBuilder sb = new StringBuilder();

  private final String source;

  private State state;

  public HttpCookiesParser(String s) {
    this.source = s;
  }

  public final Http.Cookies parse() {
    state = State.START;

    while (state != State.STOP) {
      state = execute();
    }

    if (cookies.isEmpty()) {
      return HttpCookiesEmpty.INSTANCE;
    } else {
      return new HttpCookies(cookies);
    }
  }

  private State execute() {
    return switch (state) {
      case START -> executeStart();

      case NAME -> executeName();

      case VALUE -> executeValue();

      case MALFORMED -> executeMalformed();

      case STOP -> throw new IllegalStateException("Non-executable state=" + state);
    };
  }

  private State executeName() {
    if (!hasNext()) {
      // name without value
      return State.MALFORMED;
    }

    char c;
    c = next();

    if (c == '=') {
      String name;
      name = sb.toString();

      sb.setLength(0);

      HttpRequestCookiesValue value;
      value = cookies.get(name);

      if (value == null) {
        value = HttpRequestCookiesValue.of(source, index);
      } else {
        value = value.beginNew(index);
      }

      cookies.put(name, value);

      currentValue = value;

      return State.VALUE;
    }

    sb.append(c);

    return state;
  }

  private State executeValue() {
    if (!hasNext()) {
      currentValue.endIndex(index);

      return State.STOP;
    }

    char c;
    c = next();

    if (c == ';') {
      currentValue.endIndex(index);

      return State.START;
    }

    return state;
  }

  private State executeStart() {
    if (!hasNext()) {
      return State.STOP;
    }

    char c;
    c = next();

    if (Character.isWhitespace(c)) {
      // trim initial whitespace
      return state;
    }

    if (c == '=') {
      // empty name
      return State.MALFORMED;
    }

    // name start
    sb.append(c);

    return State.NAME;
  }

  private State executeMalformed() {
    throw new UnsupportedOperationException("Implement me");
  }

  private boolean hasNext() {
    return index < source.length();
  }

  private char next() {
    return source.charAt(index++);
  }

  private enum State {
    START,

    NAME,

    VALUE,

    MALFORMED,

    STOP;
  }

}