/*

 * Copyright (C) 2009 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 com.google.gson;



import java.io.IOException;

import java.io.Reader;

import java.io.StringReader;



import com.google.gson.internal.Streams;

import com.google.gson.stream.JsonReader;

import com.google.gson.stream.JsonToken;

import com.google.gson.stream.MalformedJsonException;



/**

 * A parser to parse Json into a parse tree of {@link JsonElement}s

 *

 * @author Inderjeet Singh

 * @author Joel Leitch

 * @since 1.3

 */

public final class JsonParser {



  /**

   * Parses the specified JSON string into a parse tree

   *

   * @param json JSON text

   * @return a parse tree of {@link JsonElement}s corresponding to the specified JSON

   * @throws JsonParseException if the specified text is not valid JSON

   * @since 1.3

   */

  public JsonElement parse(String json) throws JsonSyntaxException {

    return parse(new StringReader(json));

  }



  /**

   * Parses the specified JSON string into a parse tree

   *

   * @param json JSON text

   * @return a parse tree of {@link JsonElement}s corresponding to the specified JSON

   * @throws JsonParseException if the specified text is not valid JSON

   * @since 1.3

   */

  public JsonElement parse(Reader json) throws JsonIOException, JsonSyntaxException {

    try {

      JsonReader jsonReader = new JsonReader(json);

      JsonElement element = parse(jsonReader);

      if (!element.isJsonNull() && jsonReader.peek() != JsonToken.END_DOCUMENT) {

        throw new JsonSyntaxException("Did not consume the entire document.");

      }

      return element;

    } catch (MalformedJsonException e) {

      throw new JsonSyntaxException(e);

    } catch (IOException e) {

      throw new JsonIOException(e);

    } catch (NumberFormatException e) {

      throw new JsonSyntaxException(e);

    }

  }



  /**

   * Returns the next value from the JSON stream as a parse tree.

   *

   * @throws JsonParseException if there is an IOException or if the specified

   *     text is not valid JSON

   * @since 1.6

   */

  public JsonElement parse(JsonReader json) throws JsonIOException, JsonSyntaxException {

    boolean lenient = json.isLenient();

    json.setLenient(true);

    try {

      return Streams.parse(json);

    } catch (StackOverflowError e) {

      throw new JsonParseException("Failed parsing JSON source: " + json + " to Json", e);

    } catch (OutOfMemoryError e) {

      throw new JsonParseException("Failed parsing JSON source: " + json + " to Json", e);

    } finally {

      json.setLenient(lenient);

    }

  }

}