/*
 * Copyright 2014 Effektif GmbH.
 *
 * 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.effektif.workflow.api.types;

import java.lang.reflect.Type;

import com.effektif.workflow.api.bpmn.BpmnReader;
import com.effektif.workflow.api.bpmn.BpmnWriter;
import com.effektif.workflow.api.json.TypeName;

/**
 * @author Tom Baeyens
 */
@TypeName("number")
public class NumberType extends DataType {

  public static final NumberType INSTANCE = new NumberType();

  @Override
  public Type getValueType() {
    return Number.class;
  }

  @Override
  public Object readBpmnValue(BpmnReader r) {
    return parseValue(r.readStringAttributeEffektif("value"));
  }

  @Override
  public void writeBpmnValue(BpmnWriter w, Object value) {
    if (value != null) {
      w.writeStringAttributeEffektif("value", value.toString());
    }
  }

  /**
   * Parse a text value as a Integer, Long or Double, as appropriate.
   * Based on com.fasterxml.jackson.databind.deser.std.NumberDeserializers.NumberDeserializer#deserialize(JsonParser, DeserializationContext)
   */
  private Number parseValue(String value) {
    if (value == null) {
      return null;
    }
    value = value.trim();
    try {
      boolean decimal = value.contains(".");
      if (decimal) {
        return Double.valueOf(value);
      }
      else {
        long longValue = Long.parseLong(value);
        if (longValue <= Integer.MAX_VALUE && longValue >= Integer.MIN_VALUE) {
          return (int) longValue;
        }
        return longValue;
      }
    }
    catch (NumberFormatException e) {
      return null;
    }
  }
}