package at.gv.egovernment.moa.id.commons.config;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Enumeration;
import java.util.List;
import java.util.Properties;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Unmarshaller;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import at.gv.egovernment.moa.id.commons.config.persistence.Configuration;
import at.gv.egovernment.moa.id.commons.config.persistence.JsonMapper;
import at.gv.egovernment.moa.id.commons.db.MOAIDConfigurationConstants;
import at.gv.egovernment.moa.id.commons.db.dao.config.MOAIDConfiguration;

import com.fasterxml.jackson.core.JsonProcessingException;

public class ConfigurationUtil {
	
	final boolean isOverwriteData;
	
	public ConfigurationUtil(boolean isOverwriteData){
		this.isOverwriteData = isOverwriteData;
	}

	/**
	 * Read an input MOAID 2 XML file, transfer it to properties and write the
	 * properties to a MOAID 3 property file.
	 * 
	 * @param inStream
	 *            the input stream to read from.
	 * @param outFile
	 *            the output file to write to.
	 * @throws JAXBException
	 */
	public void readFromXMLFileConvertToPropertyFile(FileInputStream inStream, File outFile) throws JAXBException {

		try (FileOutputStream outStream = new FileOutputStream(outFile);) {

			// get config from xml file
			JAXBContext jc = JAXBContext.newInstance("at.gv.egovernment.moa.id.commons.db.dao.config");
			Unmarshaller m = jc.createUnmarshaller();
			MOAIDConfiguration config = (MOAIDConfiguration) m.unmarshal(inStream);

			// serialize config to JSON properties
			Properties result = moaIdConfigToJsonProperties(config);

			// write to output stream
			result.store(outStream, null);

		} catch (FileNotFoundException e) {
			System.out.println("Could not find the output file.");
			System.exit(1);
		} catch (IOException e) {
			System.out.println("Could not write to the output file.");
			System.exit(1);
		}
	}

	/**
	 * Helper method to serialize a {@link MOAIDConfiguration} to Properties
	 * with JSON encoded values.
	 * 
	 * @param config
	 *            the MOAIDConfiguration to serialize
	 * @return {@link Properties} containing the database key and the serialized
	 *         values
	 * @throws JsonProcessingException
	 *             is thrown if problem occurred while serializing one of the
	 *             database values
	 */
	private Properties moaIdConfigToJsonProperties(MOAIDConfiguration config) throws JsonProcessingException {

		Properties result = new Properties();
		boolean prettyPrint = true;
		JsonMapper mapper = new JsonMapper(prettyPrint);

		// serialize config to JSON
		String oaJson = mapper.serialize(config.getOnlineApplication());
		String authCompGeneralJson = mapper.serialize(config.getAuthComponentGeneral());
		String chainingModeJson = mapper.serialize(config.getChainingModes());
		String defaultBKUJson = mapper.serialize(config.getDefaultBKUs());
		String genericConfigJson = mapper.serialize(config.getGenericConfiguration());
		String pvp2RefreshJson = mapper.serialize(config.getPvp2RefreshItem());
		String slRequestTemplatesJson = mapper.serialize(config.getSLRequestTemplates());
		String timestampJson = mapper.serialize(config.getTimestampItem());
		String trustedCaCertJson = mapper.serialize(config.getTrustedCACertificates());

		// add to properties
		result.put(MOAIDConfigurationConstants.ONLINE_APPLICATIONS_KEY, oaJson);
		result.put(MOAIDConfigurationConstants.AUTH_COMPONENT_GENERAL_KEY, authCompGeneralJson);
		result.put(MOAIDConfigurationConstants.CHAINING_MODES_KEY, chainingModeJson);
		result.put(MOAIDConfigurationConstants.DEFAULT_BKUS_KEY, defaultBKUJson);
		result.put(MOAIDConfigurationConstants.GENERIC_CONFIGURATION_KEY, genericConfigJson);
		result.put(MOAIDConfigurationConstants.PVP2REFRESH_ITEM_KEY, pvp2RefreshJson);
		result.put(MOAIDConfigurationConstants.SLREQUEST_TEMPLATES_KEY, slRequestTemplatesJson);
		result.put(MOAIDConfigurationConstants.TIMESTAMP_ITEM_KEY, timestampJson);
		result.put(MOAIDConfigurationConstants.TRUSTED_CERTIFICATES_KEY, trustedCaCertJson);

		return result;
	}

	/**
	 * Exports a key-value database to a property file, where keys are the same
	 * as in the database, and the values are serialized JSON objects.
	 * 
	 * @param inputDBConfigFilePath
	 *            the path to the database properties, for the db the data is
	 *            read from.
	 * @param outFile
	 *            the destination file for the exported data.
	 */
	public void readFromDBWriteToFile(String inputDBConfigFilePath, File outFile) {

		try (FileOutputStream outStream = new FileOutputStream(outFile);) {

			Properties result = new Properties();

			System.getProperties().setProperty("location", "file:" + inputDBConfigFilePath);
			ApplicationContext context = new ClassPathXmlApplicationContext("configuration.beans.xml");
			Configuration dbConfiguration = (Configuration) context.getBean("config");
			boolean prettyPrint = true;
			at.gv.egovernment.moa.id.commons.config.persistence.JsonMapper mapper = new JsonMapper(prettyPrint);

			for (String key : MOAIDConfigurationConstants.getAllMOAIDConfigurationKeys()) {

				// extract database value
				Object value = dbConfiguration.get(key);

				// serialize value to JSON
				String json = mapper.serialize(value);

				// add to properties
				result.setProperty(key, json);
			}

			// write to output stream
			result.store(outStream, null);

			System.out.println("Property configuration written to:");
			System.out.println(outFile.getAbsolutePath());

		} catch (FileNotFoundException e) {
			System.out.println("Could not find the output file.");
			System.exit(1);
		} catch (IOException e) {
			System.out.println("Could not write to the output file.");
			System.exit(1);
		}
	}

	/**
	 * Read an input property file, deserialize it's values and write them to
	 * the given database.
	 * 
	 * @param inStream
	 *            the FileInputStream to read from.
	 * @param outputDBConfigFilePath
	 *            the path to the database properties, for the db which is
	 *            written.
	 * @throws IOException
	 *             is thrown in case the properties could not be loaded from the
	 *             stream
	 */
	public void readFromFileWriteToDB(FileInputStream inStream, String outputDBConfigFilePath) throws IOException {

		Properties inProperties = new Properties();
		inProperties.load(inStream);

		System.getProperties().setProperty("location", "file:" + outputDBConfigFilePath);
		ApplicationContext context = new ClassPathXmlApplicationContext("configuration.beans.xml");
		Configuration dbConfiguration = (Configuration) context.getBean("config");
		boolean prettyPrint = true;
		JsonMapper mapper = new JsonMapper(prettyPrint);

		List<String> keys = dbConfiguration.getAllKeys();

		if (keys == null) {
			System.out.println("Database can not be read.");
			System.exit(1);
		}

		if (!keys.isEmpty() && !isOverwriteData) {
			System.out.println("The database already contains configuration data.");
			System.out.println("Use force switch if you want to override data)");
			System.exit(1);
		}

		if (isOverwriteData) {
			// remove existing entries
			for (String key : keys) {
				dbConfiguration.set(key, null);
			}
		}

		Enumeration<?> propertyNames = inProperties.propertyNames();

		while (propertyNames.hasMoreElements()) {
			String key = (String) propertyNames.nextElement();
			// extract database value
			String json = inProperties.getProperty(key);

			// deserialize value to object
			Object value = mapper.deserialize(json, null);

			// add to database
			boolean result = dbConfiguration.set(key, value);
			if (!result) {
				System.out.println("Could NOT persist the configuration file's information in the database.");
			}
		}
		System.out.println("Data has been successfully written to the database.");
	}

	private static void readFromDBWriteToDB(String inputDBConfigFilePath, String outputDBConfigFilePath) {
		//TODO: implement
	}
	
}