package com.foundation.util.json;

import java.io.IOException;
import java.io.StringWriter;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.common.comparison.Comparator;
import com.common.debug.Debug;
import com.common.exception.InvalidArgumentException;
import com.common.util.IIterator;
import com.common.util.LiteHashMap;
import com.common.util.LiteHashSet;
import com.common.util.LiteList;
import com.foundation.common.Entity;
import com.foundation.common.MetadataContainer;

/**
 * Reads and writes JSON formatted data.
 * Uses hashmaps and lists for the java side data structure.
 */
public class JsonBuilder {
private JsonBuilder() {
}//JsonBuilder()//
private static LiteHashMap readObject(JSONObject object) throws JSONException {
	String[] keys = JSONObject.getNames(object);
	LiteHashMap result = new LiteHashMap(keys.length > 10 ? keys.length : 10);
	
	for(int index = 0; index < keys.length; index++) {
		Object value = object.get(keys[index]);
		
		if(value instanceof JSONObject) {
			value = readObject((JSONObject) value);
		}//if//
		else if(value instanceof JSONArray) {
			value = readArray((JSONArray) value);
		}//else if//
		else if(value == JSONObject.NULL) {
			value = null;
		}//else if//
		
		result.put(keys[index], value);
	}//for//
	
	return result;
}//readObject()//
private static LiteList readArray(JSONArray array) throws JSONException {
	LiteList result = new LiteList(array.length() > 10 ? array.length() : 10);
	
	for(int index = 0; index < array.length(); index++) {
		Object value = array.get(index);
		
		if(value instanceof JSONObject) {
			value = readObject((JSONObject) value);
		}//if//
		else if(value instanceof JSONArray) {
			value = readArray((JSONArray) value);
		}//else if//
		else if(value == JSONObject.NULL) {
			value = null;
		}//else if//
		
		result.add(value);
	}//for//
	
	return result;
}//readArray()//
/**
 * Converts the JSON string into a collection of LiteHashMap and LiteList instances.
 * @param json
 * @return
 */
public static LiteHashMap readJson(String json) {
	try {
		JSONTokener tokener = new JSONTokener(json);
		//TODO: It may be an array starting the JSON, not an object.
		JSONObject object = new JSONObject(tokener);
		
		return readObject(object);
	}//try//
	catch(JSONException e) {
		Debug.log(e);
		throw new InvalidArgumentException("Invalid JSON string.");
	}//catch//
}//readJson()//
private static JSONObject writeObject(LiteHashMap object) throws JSONException {
	JSONObject result = new JSONObject();
	
	for(IIterator iterator = object.keyIterator(); iterator.hasNext(); ) {
		String key = (String) iterator.next();
		Object value = object.get(key);
		
		if(value instanceof LiteHashMap) {
			value = writeObject((LiteHashMap) value);
		}//if//
		else if(value instanceof LiteList) {
			value = writeArray((LiteList) value);
		}//else if//
		else if(value == null) {
			value = JSONObject.NULL;
		}//else if//
		
		result.put(key, value);
	}//for//
	
	return result;
}//writeObject()//
private static JSONArray writeArray(LiteList array) throws JSONException {
	JSONArray result = new JSONArray();
	
	for(int index = 0; index < array.getSize(); index++) {
		Object value = array.get(index);
		
		if(value instanceof LiteHashMap) {
			value = writeObject((LiteHashMap) value);
		}//if//
		else if(value instanceof LiteList) {
			value = writeArray((LiteList) value);
		}//else if//
		else if(value == null) {
			value = JSONObject.NULL;
		}//else if//
		
		result.put(value);
	}//for//
	
	return result;
}//writeArray()//
/**
 * Converts the value into a compact JSON string.
 * Includes all attributes that are not cyclical.
 * @param value The value to be converted (it will delve into collections and examine Entity objects to build the JSON string).
 * @return The JSON formatted string for the tree of objects.
 */
public static String writeJson(Object value) {
	return writeJson(value, null, null);
}//writeJson()//
/**
 * Converts the value into a JSON string.
 * Includes all attributes that are not cyclical.
 * @param indent The indent string to be used, or null if spacing should be minimized.
 * @return The JSON formatted string for the tree of objects.
 */
public static String writeJson(Object value, String indent) {
	return writeJson(value, null, indent);
}//toJson()//
/**
 * Converts the value into a compact JSON string.
 * Includes all attributes that are not cyclical.
 * @param metadataContainer The container containing metadata on what to include in the JSON.
 * @return The JSON formatted string for the tree of objects.
 */
public static String writeJson(Object value, MetadataContainer metadataContainer) {
	return writeJson(value, metadataContainer, null);
}//toJson()//
/**
 * Converts the value into a JSON string.
 * Includes all attributes that are not cyclical.
 * @param metadataContainer The container containing metadata on what to include in the JSON.
 * @param indent The indent string to be used, or null if spacing should be minimized.
 * @return The JSON formatted string for the tree of objects.
 */
public static String writeJson(Object value, MetadataContainer metadataContainer, String indent) {
	StringWriter writer = new StringWriter(10000);
	
	if(value != null) {
		try {
			Entity.jsonValue(value, metadataContainer, indent, 0, new LiteHashSet(100, Comparator.getIdentityComparator(), LiteHashSet.STYLE_NO_DUPLICATES), writer);
		}//try//
		catch(IOException e) {
			//Shouldn't ever occur.//
			Debug.log(e);
		}//catch//
		catch(Throwable e) {
			Debug.log(e);
		}//catch//
	}//if//
	
	return writer.toString();
}//toJson()//
}//JsonBuilder//