package foundation.handler.envelop;

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;

import javax.servlet.http.HttpServletResponse;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.json.JSONObject;

import com.google.gson.JsonObject;

import foundation.handler.ExistsError;
import foundation.handler.MessageList;
import foundation.handler.ResultItem;
import foundation.handler.ResultPool;
import foundation.handler.Validation;
import foundation.json.IJSONProvider;
import foundation.json.JSONWriter;

public class EnvelopWriter {

	public final static String Code_URL = "url";

	protected static Logger logger;
	private HttpServletResponse response;
	protected JSONWriter writer;    		// 响应字符流
	protected OutputStream outputStream; 	// 响应字节流
	private Stack<Boolean> notEmpty;

	static {
		logger = LogManager.getLogger(EnvelopWriter.class);
	}

	public EnvelopWriter(HttpServletResponse response) throws IOException {
		this.response = response;
		notEmpty = new Stack<Boolean>();
	}
	
	public void replay(ResultPool result) throws Exception {
		if (response.isCommitted()) {
			return;
		}
		
		createJsonWriter();
		
		writer.beginObject();
		try {
			//1. write success
			writer.write(IEnvelop.ResultCode_Success, result.isSuccess());
			
			//2. write validation
			writeValidation(writer, result.getValidation());
			
			//3. write message list
			writeMessageList(writer, result.getMessageList());
			
			//4. write message list
			writeExistsErrors(writer, result.getExistsErrors());			
			
			//2. write letter
			ILetterWriter letterWriter = result.getLetterWriter();
			
			if (letterWriter != null) {
				try {
					 letterWriter.write(writer);
				} catch(Exception e) {
					 System.out.println(e.getMessage());
				}
				
				List<ResultItem> attachments = letterWriter.getItemList();
				writeResultItems(attachments);
			}
			//3. write item list
			else {
				writer.beginObject("data");
				List<ResultItem> itemList = result.getItemList();
				writeResultItems(itemList);
				writer.endObject();
			}
		}
		finally {
			writer.endObject();
		}
	}

	private void writeValidation(JSONWriter writer, Validation validation) {
		if (validation == null) {
			writer.writeNull("validation");
			return;
		}
		
		validation.writeJSON(writer);
	}

	private void writeMessageList(JSONWriter writer, MessageList messageList) {
		if (messageList == null) {
			writer.writeNull("messages");
			return;
		}
		
		messageList.writeJSON(writer);
	}
	
	private void writeExistsErrors(JSONWriter writer, List<ExistsError> existsErrors) {
		if (existsErrors == null) {
			writer.writeNull("exists_errors");
			return;
		}
		
		writer.beginArray("exists_errors");
		
		for (ExistsError error: existsErrors) {
			writer.beginObject();
			writer.write("error_type", error.getErrorType());
			writer.write("title", error.getTitle());
			writer.write("errors", error.getErrorSet());
			writer.endObject();
		}
		
		writer.endArray();
	}
	
	private void writeResultItems(List<ResultItem> itemList) throws Exception {
		for (ResultItem item: itemList) {
			String name = item.getName(); 
			Object value = item.getValue();
			writeData(name, value);
		}		
	}

	private void writeData(String name, Object value) throws Exception {
		if (value == null) {
			writer.writeNull(name);
			return;
		}
		
		//1. entity、entitySet、entityTree、page ...
		if (value instanceof IJSONProvider) {
			writeJsonProvider(name, (IJSONProvider) value);
		}
		//2. collection
		else if (value instanceof Collection) {
			writeCollection(name, (Collection<?>) value);
		}
		//3. iterator
		else if (value instanceof Iterable<?>) {
			writeIterable(name, (Iterable<?>) value);
		}	
		//4. map
		else if (value instanceof Map<?, ?>) {
			writeMap(name, (Map<?, ?>)value);
		}
		else if (value instanceof IRawJson) {
            JSONObject jsonObject = new JSONObject(value);
            this.writer.writeJSON(name, jsonObject.toString());
        } 
		else if (value instanceof JSONObject || value instanceof JsonObject) {
            this.writer.writeJSON(name, value.toString());
        } 		
		//6. string、integer、double、decimal、boolean、date、object ...
		else {
			writeObject(name, value);
		}
	}

	private void writeMap(String name, Map<?, ?> value) throws Exception {
		//1. name
		if (name != null) {
			writer.writeName(name);
		}
		
		//2. null data 
		if (value == null) {
			writer.writeNull();
			return;
		}
		
		//3. collection data
		writer.beginObject();
		Set<?> keySet = value.keySet();
		
		for (Object key : keySet) {
			Object obj = value.get(key);
			writeData(key.toString(), obj);
		}

		writer.endObject();
		
	}

	private void writeJsonProvider(String name, IJSONProvider jsonProvider) {
		//1. name
		if (name != null) {
			writer.writeName(name);
			
			if (jsonProvider == null) {
				writer.writeNull();
				return;
			}
		}
		
		//2. data
		jsonProvider.writeJSON(writer);
	}
	
	private void writeCollection(String name, Collection<?> collection) throws Exception {
		//1. name
		if (name != null) {
			writer.writeName(name);
		}
		
		//2. null data 
		if (collection == null) {
			writer.writeNull();
			return;
		}
		
		//3. collection data
		writer.beginArray();
		
		//何飞侠修改20210728
		for (Object obj : collection) {
			 writeData(null, obj);
		}

		writer.endArray();
	}

	private void writeIterable(String name, Iterable<?> iterable) throws Exception {
		//1. name
		if (name != null) {
			writer.writeName(name);
		}
		
		//2. null data 
		if (iterable == null) {
			writer.writeNull();
			return;
		}
		
		//3. collection data
		writer.beginArray();
		
		Iterator<?> iterator = iterable.iterator();
		
		while(iterator.hasNext()) {
			Object obj = iterator.next();
			writeData(null, obj);
		}

		writer.endArray();		
	}

	private void writeObject(String name, Object value) throws Exception {
		//1. null data 
		if (value == null) {
			writer.writeNull(name);
			return;
		}
		
		if (value instanceof String) {
			writer.write(name, (String) value);
		}
		else if (value instanceof Integer) {
			writer.write(name, (Integer) value);
		}
		else if (value instanceof Long) {
			writer.write(name, (Long) value);
		}
		else if (value instanceof Double) {
			writer.write(name, (Double) value);
		}		
		else if (value instanceof BigDecimal) {
			writer.write(name, (BigDecimal) value);
		}
		else if (value instanceof Date) {
			writer.write(name, (Date) value);
		}
		else if (value instanceof Boolean) {
			writer.write(name, (Boolean) value);
		}
		else if (value instanceof Enum) {
			writer.write(name, value.toString());
		}
		else if (value instanceof IJSONProvider) {
			writer.writeName(name);
			IJSONProvider jsonAvailable = (IJSONProvider) value;
			jsonAvailable.writeJSON(writer);
		}
	}

	public void flush() {
		if (writer != null) {
			try {
				writer.flush();
				writer.close();
			}
			catch (Exception e) {
				logger.error(e);
			}
		}

		if (outputStream != null) {
			try {
				outputStream.flush();
				outputStream.close();
			}
			catch (Exception e) {
				logger.error(e);
			}
		}
	}

	private void createJsonWriter() throws IOException {// 获取指向浏览器的字符输出流
		response.setCharacterEncoding("UTF-8");
		
		PrintWriter printerWriter = response.getWriter();
		writer = new JSONWriter(printerWriter);
		
		notEmpty.clear();
		notEmpty.add(false);
	}


}