/*

  * 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.johnzon.core;

 import java.io.OutputStream;

 import java.io.Serializable;

 import java.io.Writer;

 import java.nio.charset.Charset;

 import java.util.Collection;

 import java.util.Collections;

 import java.util.HashMap;

 import java.util.Locale;

 import java.util.Map;

 import java.util.concurrent.ConcurrentMap;

 import javax.json.stream.JsonGenerator;

 import javax.json.stream.JsonGeneratorFactory;

 import static java.util.Arrays.asList;

 public class JsonGeneratorFactoryImpl implements JsonGeneratorFactory, Serializable {    

     public static final String BUFFER_LENGTH = "org.apache.johnzon.default-char-buffer-generator";

     public static final int DEFAULT_BUFFER_LENGTH = Integer.getInteger(BUFFER_LENGTH, 1024); //TODO check default string length/buffer size

     private final Map<String, Object> internalConfig = new HashMap<String, Object>();

     private static final Collection<String> SUPPORTED_CONFIG_KEYS = asList(

         JsonGenerator.PRETTY_PRINTING, BUFFER_LENGTH, JsonParserFactoryImpl.BUFFER_STRATEGY

     );

     //key caching currently disabled

     private final ConcurrentMap<String, String> cache = null;//new ConcurrentHashMap<String, String>();

     private final boolean pretty;

     private final BufferStrategy.BufferProvider<char[]> bufferProvider;

     public JsonGeneratorFactoryImpl(final Map<String, ?> config) {

           if(config != null) {

               for (String configKey : config.keySet()) {

                   if(SUPPORTED_CONFIG_KEYS.contains(configKey)) {

                       internalConfig.put(configKey, config.get(configKey));

                   }

               }

           } 

           if(internalConfig.containsKey(JsonGenerator.PRETTY_PRINTING)) {

               this.pretty = Boolean.TRUE.equals(internalConfig.get(JsonGenerator.PRETTY_PRINTING)) || "true".equals(internalConfig.get(JsonGenerator.PRETTY_PRINTING));

           } else {

               this.pretty = false;

           }

           final int bufferSize = getInt(BUFFER_LENGTH);

           if (bufferSize <= 0) {

               throw new IllegalArgumentException("buffer length must be greater than zero");

           }

           this.bufferProvider = getBufferProvider().newCharProvider(bufferSize);

     }

     private BufferStrategy getBufferProvider() {

         final Object name = internalConfig.get(JsonParserFactoryImpl.BUFFER_STRATEGY);

         if (name != null) {

             return BufferStrategy.valueOf(name.toString().toUpperCase(Locale.ENGLISH));

         }

         return BufferStrategy.QUEUE;

     }

     private int getInt(final String key) {

         final Object maxStringSize = internalConfig.get(key);

         if (maxStringSize == null) {

             return DEFAULT_BUFFER_LENGTH;

         } else if (Number.class.isInstance(maxStringSize)) {

             return Number.class.cast(maxStringSize).intValue();

         }

         return Integer.parseInt(maxStringSize.toString());

     }

     @Override

     public JsonGenerator createGenerator(final Writer writer) {

         if (pretty) {

             return new JsonPrettyGeneratorImpl(writer, bufferProvider, cache);

         }

         return new JsonGeneratorImpl(writer, bufferProvider, cache);

     }

     @Override

     public JsonGenerator createGenerator(final OutputStream out) {

         if (pretty) {

             return new JsonPrettyGeneratorImpl(out, bufferProvider, cache);

         }

         return new JsonGeneratorImpl(out, bufferProvider, cache);

     }

     @Override

     public JsonGenerator createGenerator(final OutputStream out, final Charset charset) {

         if (pretty) {

             return new JsonPrettyGeneratorImpl(out,charset, bufferProvider, cache);

         }

         return new JsonGeneratorImpl(out,charset, bufferProvider, cache);

     }

     @Override

     public Map<String, ?> getConfigInUse() {

         return Collections.unmodifiableMap(internalConfig);

     }

 }