/**
 * Copyright 2010 Google Inc.
 *
 * 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 org.waveprotocol.wave.model.document.parser;

import org.waveprotocol.wave.model.util.StringMap;

import java.util.NoSuchElementException;

/**
 * Xml pull parser interface that throws checked exceptions while parsing when
 * malformed xml is encountered.
 *
 */
public interface XmlPullParser {
  /**
   * @return if the parser has more tokens.
   */
  boolean hasNext();

  /**
   * Move to the next token
   * @return The type of item we are at
   * @throws XmlParseException if we encounter malformed xml
   */
  ItemType next() throws XmlParseException, NoSuchElementException;

  /**
   * @return Type of item at current position
   */
  ItemType getCurrentType();

  /**
   * @return character data at current position; only valid when we are at a
   *         text item
   * @throws IllegalArgumentException if the cursor is not at a text node.
   */
  String getText() throws IllegalStateException;

  /**
   * @return tag name for current start element; not valid over other items
   * @throws IllegalStateException if the cursor is not at an element start/end
   */
  String getTagName() throws IllegalStateException;

  /**
   * @return attributes for current start element; not valid over other items
   *
   *         NOTE(user): This returns a new map and the implementation should
   *         hold no reference to it. Callers may use this directly without
   *         making defensive copies.
   * @throws IllegalStateException if the cursor is not at an element start.
   */
  StringMap<String> getAttributes() throws IllegalStateException;

  /**
   * @return the name of the current processing instruction.
   * @throws IllegalStateException if the cursor is not at a processing
   *         instruction.
   */
  String getProcessingInstructionName() throws IllegalStateException;

  /**
   * @return the value of the current processing instruction
   * @throws IllegalStateException if the cursor is not at a processing
   *         instruction
   */
  String getProcessingInstructionValue() throws IllegalStateException;
}