/*
 * Copyright (C) 2011 Citrix Systems, Inc.  All rights reserved.
 * 
 * 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.cloud.bridge.util;

import java.io.PrintWriter;
import java.lang.reflect.Field;
import java.util.Calendar;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;

/**
 * @author Kelven Yang
 */
public class XSerializerJsonAdapter implements XSerializerAdapter {
	private XSerializer serializer;
	
	public XSerializerJsonAdapter() {
	}
	
	@Override
	public void setSerializer(XSerializer serializer) {
		this.serializer = serializer; 
	}

	@Override
	public void beginElement(String element, String namespace, int indentLevel, PrintWriter writer) {
		indent(true, indentLevel, writer);
		if(element != null && !element.isEmpty())
			writer.print(element + ": {");
		else
			writer.print("{");
	}
	
	@Override
	public void endElement(String element, int indentLevel, PrintWriter writer) {
		indent(true, indentLevel, writer);
		writer.print("}");
	}
	
	@Override
	public void writeElement(String elementName, String itemName, Object value, Field f, int indentLevel, PrintWriter writer) {
		Class<?> fieldType = f.getType();
		if(!serializer.isComposite(fieldType)) {
			if(fieldType == Date.class) {
				if(value != null) {
					indent(true, indentLevel, writer);
					writer.print(elementName + ":\"");
					writer.print(DateHelper.getGMTDateFormat("yyyy-MM-dd").format((Date)value) + "T" 
						+ DateHelper.getGMTDateFormat("HH:mm:ss").format((Date)value) + ".000Z");
					writer.print("\"");
				} else {
					if(!serializer.omitNullField(f)) {
						indent(true, indentLevel, writer);
						writer.print(elementName + ":null");
					}
				}
			} else if(fieldType == Calendar.class) {
				if(value != null) {
					indent(true, indentLevel, writer);
					
					Date dt = ((Calendar)value).getTime();
					writer.print(elementName + ":\"");
					writer.print(DateHelper.getGMTDateFormat("yyyy-MM-dd").format(dt) + "T" 
						+ DateHelper.getGMTDateFormat("HH:mm:ss").format(dt) + ".000Z");
					writer.print("\"");
				} else {
					if(!serializer.omitNullField(f)) {
						indent(true, indentLevel, writer);
						writer.print(elementName + ":null");
					}
				}
			} else {
				if(value != null) {
					indent(true, indentLevel, writer);
					writer.print(elementName + ":\"");
					writer.print(value);
					writer.print("\"");
				} else {
					if(!serializer.omitNullField(f)) {
						indent(true, indentLevel, writer);
						writer.print(elementName + ":null");
					}
				}
			}
		} else if(fieldType.isArray()) {
			if(value != null) {
				indent(true, indentLevel, writer);
				writer.print(elementName + ":[");
				indentLevel++;
	
				Object[] array = (Object[])value;
				
				for(int i = 0; i < array.length; i++) {
					serializer.serializeTo(array[i], "", null, indentLevel, writer);
					
					if(i < array.length - 1)
						writeSeparator(indentLevel, writer);
				}
				
				indentLevel--;
				indent(true, indentLevel, writer);
				writer.print("]");
			} else {
				if(!serializer.omitNullField(f)) {
					indent(true, indentLevel, writer);
					writer.print(elementName + ":null");
				}
			}
		}  else if (Collection.class.isAssignableFrom(fieldType)) {
			if(value != null) {
				indent(true, indentLevel, writer);
				writer.print(elementName + ":[");
				indentLevel++;
				
				Iterator it = ((Collection)value).iterator();
				if(it != null) {
					while(it.hasNext()) {
						Object sub = it.next();
						serializer.serializeTo(sub, "", null, indentLevel, writer);
						
						if(it.hasNext())
							writeSeparator(indentLevel, writer);
					}
				}
				
				indentLevel--;
				indent(true, indentLevel, writer);
				writer.print("]");
			} else {
				if(!serializer.omitNullField(f)) {
					indent(true, indentLevel, writer);
					writer.print(elementName + ":null");
				}
			}
		} else {
			serializer.serializeTo(value, elementName, null, indentLevel, writer);
		}
	}
	
	@Override
	public void writeSeparator(int indentLevel, PrintWriter writer) {
		writer.print(",");
	}
	
	private void indent(boolean newLine, int indentLevel, PrintWriter writer) {
		if(newLine)
			writer.println("");
		for(int i = 0; i < indentLevel; i++)
			writer.append("    ");
	}
}