// Copyright (c) 2009 The Chromium Authors. All rights reserved.

// Use of this source code is governed by a BSD-style license that can be

// found in the LICENSE file.

package org.chromium.sdk.internal;

import java.io.IOException;

import java.io.StringWriter;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.json.simple.JSONArray;

import org.json.simple.JSONObject;

import org.json.simple.JSONStreamAware;

import org.json.simple.parser.JSONParser;

import org.json.simple.parser.ParseException;

/**

 * A utility for JSON-related data conversion.

 */

public class JsonUtil {

  private static final Logger LOGGER = Logger.getLogger(JsonUtil.class.getName());

  /**

   * Converts a JSONStreamAware into a String.

   *

   * @param object the object to convert

   * @return a JSON String representation of the object

   */

  public static String streamAwareToJson(JSONStreamAware object) {

    StringWriter out = new StringWriter();

    try {

      object.writeJSONString(out);

    } catch (IOException e) {

      return null;

    }

    return out.toString();

  }

  /**

   * @param json a JSON representation of an object (rather than an array or any

   *        other type)

   * @return a JSONObject represented by json, or null if json does not

   *         represent a valid JSONObject

   * @throws ParseException

   */

  public static JSONObject jsonObjectFromJson(String json) throws ParseException {

    JSONParser p = new JSONParser();

    Object parsed = p.parse(json);

    if (false == parsed instanceof JSONObject) {

      LOGGER.log(Level.SEVERE, "Not a JSON object: {0}", json);

      return null;

    }

    return (JSONObject) parsed;

  }

  /**

   * Helper function to rip out an integer number from a JSON payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return null if key not found or bad type

   */

  public static Long getAsLong(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof Long || v == null) {

      return (Long) v;

    }

    LOGGER.log(Level.SEVERE, "Key: {0}, found value: {1}", new Object[] {keyString, v});

    return null;

  }

  /**

   * Helper function to rip out a double from a JSON payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return null if key not found or bad type

   */

  public static Double getAsDouble(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof Double || v == null) {

      return (Double) v;

    }

    LOGGER.log(Level.SEVERE, "Key: {0}, found value: {1}", new Object[] {keyString, v});

    return null;

  }

  /**

   * Helper function to rip out a string from a JSON payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return null if key not found or bad type

   */

  public static String getAsString(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof String || v == null) {

      return (String) v;

    }

    return String.valueOf(v);

  }

  /**

   * Helper function to rip out a Boolean from a JSON payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return Boolean.FALSE if key not found

   */

  public static Boolean getAsBoolean(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof Boolean || v == null) {

      return v != null

          ? (Boolean) v

          : false;

    }

    LOGGER.log(Level.SEVERE, "Key: {0}, found value: {1}", new Object[] {keyString, v});

    return false;

  }

  /**

   * Helper function to rip out a nested JSON object from the payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return null if key not found

   */

  public static JSONObject getAsJSON(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof JSONObject || v == null) {

      return (JSONObject) v;

    }

    LOGGER.log(Level.SEVERE, "Key: {0}, found value: {1}", new Object[] {keyString, v});

    return null;

  }

  /**

   * Helper function to rip out a nested JSON object from the payload or throw an exception.

   * @param obj JSON payload

   * @param key to look up

   * @return not null

   * @throws JsonException if failed to rip out the object

   */

  public static JSONObject getAsJSONStrict(JSONObject obj, CharSequence key) {

    JSONObject result = getAsJSON(obj, key);

    if (result == null) {

      throw new JsonException("Failed to find property '" + key);

    }

    return result;

  }

  /**

   * Helper function to rip out a JSONArray from the payload.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return null if key not found

   */

  public static JSONArray getAsJSONArray(JSONObject obj, CharSequence key) {

    String keyString = key.toString();

    Object v = obj.get(keyString);

    if (v instanceof JSONArray || v == null) {

      return (JSONArray) v;

    }

    LOGGER.log(Level.SEVERE, "Key: {0}, found value: {1}", new Object[] {keyString, v});

    return null;

  }

  /**

   * Helper function to rip out a JSONArray from the payload or throw an exception.

   *

   * @param obj JSON payload

   * @param key to look up

   * @return not null

   * @throws JsonException if failed to rip out the array

   */

  public static JSONArray getAsJSONArrayStrict(JSONObject obj, CharSequence key) {

    JSONArray result = getAsJSONArray(obj, key);

    if (result == null) {

      throw new JsonException("Failed to find property '" + key + "' of array type");

    }

    return result;

  }

  /**

   * @param value to check

   * @return whether the value can be parsed as an integer

   */

  public static boolean isInteger(String value) {

    try {

      Integer.parseInt(value);

      return true;

    } catch (NumberFormatException e) {

      return false;

    }

  }

  public static String quoteString(String string) {

    return "\"" + string + "\"";

  }

  private JsonUtil() {

    // not instantiable

  }

}