/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.chemistry.opencmis.commons.impl.json;
  
  import java.io.IOException;
  import java.io.Reader;
  import java.io.StringReader;
  import java.io.Writer;
  import java.math.BigDecimal;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.chemistry.opencmis.commons.impl.json.parser.JSONParseException;
  import org.apache.chemistry.opencmis.commons.impl.json.parser.JSONParser;
  
  /**
   * (Taken from JSON.simple <http://code.google.com/p/json-simple/> and modified
   * for OpenCMIS.)
   * 
   * @author FangYidong<fangyidong@yahoo.com.cn>
   */
  public final class JSONValue {
  
      private JSONValue() {
      }
  
      /**
       * Parse JSON text into java object from the input source. Please use
       * parseWithException() if you don't want to ignore the exception.
       * 
       * @see org.json.simple.parser.JSONParser#parse(Reader)
       * @see #parseWithException(Reader)
       * 
       * @param in
       * @return Instance of the following: org.json.simple.JSONObject,
       *         org.json.simple.JSONArray, java.lang.String, java.lang.Number,
       *         java.lang.Boolean, null
       * 
       */
      public static Object parse(Reader in) {
          try {
              JSONParser parser = new JSONParser();
              return parser.parse(in);
          } catch (Exception e) {
              return null;
          }
      }
  
      public static Object parse(String s) {
          StringReader in = new StringReader(s);
          return parse(in);
      }
  
      /**
       * Parse JSON text into java object from the input source.
       * 
       * @see org.json.simple.parser.JSONParser
       * 
       * @param in
       * @return Instance of the following: org.json.simple.JSONObject,
       *         org.json.simple.JSONArray, java.lang.String, java.lang.Number,
       *         java.lang.Boolean, null
       * 
       * @throws IOException
       * @throws JSONParseException
       */
      public static Object parseWithException(Reader in) throws IOException, JSONParseException {
          JSONParser parser = new JSONParser();
          return parser.parse(in);
      }
  
      public static Object parseWithException(String s) throws JSONParseException {
          JSONParser parser = new JSONParser();
          return parser.parse(s);
      }
  
      /**
       * Encode an object into JSON text and write it to out.
       * <p>
       * If this object is a Map or a List, and it's also a JSONStreamAware or a
       * JSONAware, JSONStreamAware or JSONAware will be considered firstly.
       * <p>
       * DO NOT call this method from writeJSONString(Writer) of a class that
      * implements both JSONStreamAware and (Map or List) with "this" as the
      * first parameter, use JSONObject.writeJSONString(Map, Writer) or
      * JSONArray.writeJSONString(List, Writer) instead.
      * 
      * @see org.json.simple.JSONObject#writeJSONString(Map, Writer)
      * @see org.json.simple.JSONArray#writeJSONString(List, Writer)
      * 
      * @param value
      * @param writer
      */
     @SuppressWarnings("unchecked")
     public static void writeJSONString(Object value, Writer out) throws IOException {
         if (value == null) {
             out.write("null");
             return;
         }
 
         if (value instanceof String) {
             out.write('\"');
             out.write(escape((String) value));
             out.write('\"');
             return;
         }
 
         if (value instanceof Double) {
             if (((Double) value).isInfinite() || ((Double) value).isNaN()) {
                 out.write("null");
             } else {
                 out.write(value.toString());
             }
             return;
         }
 
         if (value instanceof Float) {
             if (((Float) value).isInfinite() || ((Float) value).isNaN()) {
                 out.write("null");
             } else {
                 out.write(value.toString());
             }
             return;
         }
 
         if (value instanceof BigDecimal) {
             out.write(((BigDecimal) value).toPlainString());
             return;
         }
 
         if (value instanceof Number) {
             out.write(value.toString());
             return;
         }
 
         if (value instanceof Boolean) {
             out.write(value.toString());
             return;
         }
 
         if (value instanceof JSONStreamAware) {
             ((JSONStreamAware) value).writeJSONString(out);
             return;
         }
 
         if (value instanceof JSONAware) {
             out.write(((JSONAware) value).toJSONString());
             return;
         }
 
         if (value instanceof Map) {
             JSONObject.writeJSONString((Map<String, Object>) value, out);
             return;
         }
 
         if (value instanceof List) {
             JSONArray.writeJSONString((List<Object>) value, out);
             return;
         }
 
         out.write(value.toString());
     }
 
     /**
      * Convert an object to JSON text.
      * <p>
      * If this object is a Map or a List, and it's also a JSONAware, JSONAware
      * will be considered firstly.
      * <p>
      * DO NOT call this method from toJSONString() of a class that implements
      * both JSONAware and Map or List with "this" as the parameter, use
      * JSONObject.toJSONString(Map) or JSONArray.toJSONString(List) instead.
      * 
      * @see org.json.simple.JSONObject#toJSONString(Map)
      * @see org.json.simple.JSONArray#toJSONString(List)
      * 
      * @param value
      * @return JSON text, or "null" if value is null or it's an NaN or an INF
      *         number.
      */
     @SuppressWarnings("unchecked")
     public static String toJSONString(Object value) {
         if (value == null) {
             return "null";
         }
 
         if (value instanceof String) {
             return "\"" + escape((String) value) + "\"";
         }
 
         if (value instanceof Double) {
             if (((Double) value).isInfinite() || ((Double) value).isNaN()) {
                 return "null";
             } else {
                 return value.toString();
             }
         }
 
         if (value instanceof Float) {
             if (((Float) value).isInfinite() || ((Float) value).isNaN()) {
                 return "null";
             } else {
                 return value.toString();
             }
         }
 
         if (value instanceof BigDecimal) {
             return ((BigDecimal) value).toPlainString();
         }
 
         if (value instanceof Number) {
             return value.toString();
         }
 
         if (value instanceof Boolean) {
             return value.toString();
         }
 
         if (value instanceof JSONAware) {
             return ((JSONAware) value).toJSONString();
         }
 
         if (value instanceof Map) {
             return JSONObject.toJSONString((Map<String, Object>) value);
         }
 
         if (value instanceof List) {
             return JSONArray.toJSONString((List<Object>) value);
         }
 
         return value.toString();
     }
 
     /**
      * Escape quotes, \, /, \r, \n, \b, \f, \t and other control characters
      * (U+0000 through U+001F).
      * 
      * @param s
      * @return
      */
     public static String escape(String s) {
         if (s == null) {
             return null;
         }
 
         StringBuilder sb = new StringBuilder();
         escape(s, sb);
         return sb.toString();
     }
 
     /**
      * @param s
      *            - Must not be null.
      * @param sb
      */
     static void escape(String s, StringBuilder sb) {
         for (int i = 0; i < s.length(); i++) {
             char ch = s.charAt(i);
             switch (ch) {
             case '"':
                 sb.append("\\\"");
                 break;
             case '\\':
                 sb.append("\\\\");
                 break;
             case '\b':
                 sb.append("\\b");
                 break;
             case '\f':
                 sb.append("\\f");
                 break;
             case '\n':
                 sb.append("\\n");
                 break;
             case '\r':
                 sb.append("\\r");
                 break;
             case '\t':
                 sb.append("\\t");
                 break;
             case '/':
                 sb.append("\\/");
                 break;
             default:
                 // Reference: http://www.unicode.org/versions/Unicode5.1.0/
                 if ((ch >= '\u0000' && ch <= '\u001F') || (ch >= '\u007F' && ch <= '\u009F')
                         || (ch >= '\u2000' && ch <= '\u20FF')) {
                     String ss = Integer.toHexString(ch);
                     sb.append("\\u");
                     for (int k = 0; k < 4 - ss.length(); k++) {
                         sb.append('0');
                     }
                     sb.append(ss.toUpperCase());
                 } else {
                     sb.append(ch);
                 }
             }
         }// for
     }
 }