/*

  * 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.InputStream;

 import java.io.Reader;

 import java.io.Serializable;

 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.logging.Logger;

 import javax.json.JsonArray;

 import javax.json.JsonObject;

 import javax.json.stream.JsonParser;

 import javax.json.stream.JsonParserFactory;

 import static java.util.Arrays.asList;

 class JsonParserFactoryImpl implements JsonParserFactory, Serializable {

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

     public static final String BUFFER_STRATEGY = "org.apache.johnzon.buffer-strategy";

     public static final String MAX_STRING_LENGTH = "org.apache.johnzon.max-string-length";

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

     public static final String SUPPORTS_COMMENTS = "org.apache.johnzon.supports-comments";

     public static final int DEFAULT_MAX_SIZE = Integer.getInteger(MAX_STRING_LENGTH, 8192*32); //TODO check default string length/buffer size

     public static final boolean DEFAULT_SUPPORTS_COMMENT = false;

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

     private static final Collection<String> SUPPORTED_CONFIG_KEYS = asList(

         BUFFER_STRATEGY, MAX_STRING_LENGTH, BUFFER_LENGTH, SUPPORTS_COMMENTS

     );

     private final int maxSize;

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

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

     private final boolean supportsComments;

     JsonParserFactoryImpl(final Map<String, ?> config) {

         if(config != null) {

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

                 if(SUPPORTED_CONFIG_KEYS.contains(configKey)) {

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

                 } else {

                     LOGGER.warning(configKey + " is not supported by " + getClass().getName());

                 }

             }

         } 

         final int bufferSize = getInt(BUFFER_LENGTH);

         if (bufferSize <= 0) {

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

         }

         this.maxSize = getInt(MAX_STRING_LENGTH);

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

         this.valueBufferProvider = getBufferProvider().newCharProvider(maxSize);

         this.supportsComments = getBool(SUPPORTS_COMMENTS);

     }

     private BufferStrategy getBufferProvider() {

         final Object name = internalConfig.get(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_MAX_SIZE;

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

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

         }

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

     }

     private boolean getBool(final String key) {

         final Object maxStringSize = internalConfig.get(key);

         if (maxStringSize == null) {

             return DEFAULT_SUPPORTS_COMMENT;

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

             return Boolean.class.cast(maxStringSize);

         }

         return Boolean.parseBoolean(maxStringSize.toString());

     }

     private JsonParser getDefaultJsonParserImpl(final InputStream in) {

         if (supportsComments) {

             return new CommentsJsonStreamParserImpl(in, maxSize, bufferProvider, valueBufferProvider);

         }

         //UTF Auto detection RFC 4627

         return new JsonStreamParserImpl(in, maxSize, bufferProvider, valueBufferProvider);

     }

     private JsonParser getDefaultJsonParserImpl(final InputStream in, final Charset charset) {

         if (supportsComments) {

             return new CommentsJsonStreamParserImpl(in, charset, maxSize, bufferProvider, valueBufferProvider);

         }

         //use provided charset

         return new JsonStreamParserImpl(in, charset, maxSize, bufferProvider, valueBufferProvider);

     }

     private JsonParser getDefaultJsonParserImpl(final Reader in) {

         if (supportsComments) {

             return new CommentsJsonStreamParserImpl(in, maxSize, bufferProvider, valueBufferProvider);

         }

         //no charset necessary

         return new JsonStreamParserImpl(in, maxSize, bufferProvider, valueBufferProvider);

     }

     @Override

     public JsonParser createParser(final Reader reader) {

         return getDefaultJsonParserImpl(reader);

     }

     @Override

     public JsonParser createParser(final InputStream in) {

         return getDefaultJsonParserImpl(in);

     }

     @Override

     public JsonParser createParser(final InputStream in, final Charset charset) {

         return getDefaultJsonParserImpl(in, charset);

     }

     @Override

     public JsonParser createParser(final JsonObject obj) {

         // no need of a comment version since JsonObject has no comment event

         return new JsonInMemoryParser(obj);

     }

     @Override

     public JsonParser createParser(final JsonArray array) {

         // no need of a comment version since JsonObject has no comment event

         return new JsonInMemoryParser(array);

     }

     @Override

     public Map<String, ?> getConfigInUse() {

         return Collections.unmodifiableMap(internalConfig);

     }

     public JsonParser createInternalParser(final InputStream in) {

         return getDefaultJsonParserImpl(in);

     }

     public JsonParser createInternalParser(final InputStream in, final Charset charset) {

         return getDefaultJsonParserImpl(in, charset);

     }

     public JsonParser createInternalParser(final Reader reader) {

         return getDefaultJsonParserImpl(reader);

     }

 }