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

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.regex.Pattern;

import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import at.gv.egiz.components.configuration.api.AbstractConfigurationImpl;
import at.gv.egiz.components.configuration.api.ConfigurationException;
import at.gv.egovernment.moa.util.MiscUtil;

/**
 * Database backed implementation of the DAO interface
 * 
 */
@Repository
@Transactional("transactionManager")
public class DatabaseConfigPropertyImpl extends AbstractConfigurationImpl {

	private Logger log = LoggerFactory.getLogger(getClass());

	@PersistenceContext(unitName = "config")
	private EntityManager em;
	
	@Autowired(required=true)
	private ApplicationContext appContext;

	static protected String dataBaseEntityName;
		
	@PostConstruct
	void postConstructor() {
		dataBaseEntityName = appContext.getBean(AbstractConfigProperty.class).getImplementationName();
		log.info("DB-Entity for config: " + dataBaseEntityName);
		
	}
	
	/**
	 * 
	 * @return EntityManager for database access
	 */
	protected EntityManager getPersistenceContext() {
		return em;
	}
	
	@Override
	protected List<String> getAllKeys() throws ConfigurationException {
		if (null == em) {
			log.error("No EntityManager set!");
			throw new ConfigurationException("No EntityManager set!");
		}
		TypedQuery<String> query = em.createQuery("select key from " + dataBaseEntityName, String.class);
		List<String> result = query.getResultList();
		return result;
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#getValue(java.lang.String)
	 */
	@Override
	protected String getValue(String key) throws ConfigurationException {
		AbstractConfigProperty property = getProperty(key);
		if (property == null)
			return null;
			
		 else {
			 if (MiscUtil.isEmpty(property.getValue()))
				 return new String();
			 else
				 return property.getValue();
			 
		 }
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#containsKey(java.lang.String)
	 */
	@Override
	protected boolean containsKey(String key) throws ConfigurationException {
		AbstractConfigProperty property = getProperty(key);
		if (property == null)
			return false;
		else
			return true;
				
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#storeKey(java.lang.String, java.lang.String)
	 */
	@Override
	@Transactional("transactionManager")
	protected void storeKey(String key, String value) throws ConfigurationException {
		if (null == em) {
			log.error("No EntityManager set!");
			throw new ConfigurationException("No EntityManager set!");
			
		}
		AbstractConfigProperty property = appContext.getBean(AbstractConfigProperty.class);
		property.setKey(key);
		property.setValue(value);		
		log.debug("Storing '{}'.", property.toString());
//		em.persist(property);
		em.merge(property);
		
	}
	
	protected void deleteKey(String key) {
		log.debug("Deleting entry with key '{}'.", key);
		AbstractConfigProperty el = em.find(appContext.getBean(AbstractConfigProperty.class).getClass(), key);
		if (el != null)
			em.remove(el);
			
	}
	
	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#findConfigurationId(java.lang.String)
	 */
	@Override
	public String[] findConfigurationId(String searchString)
			throws ConfigurationException {				
		if (null == em) {
			log.error("No EntityManager set!");
			throw new ConfigurationException("No EntityManager set!");
		}
		
		TypedQuery<String> query = em.createQuery("select key from " + dataBaseEntityName + " dbconfig where dbconfig.key like :key", String.class);
		query.setParameter("key", searchString.replace("*", "%"));
		List<String> result = query.getResultList();
		if (result == null)
			return null;
		else
			return result.toArray(new String[result.size()]);
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#findByValue(java.lang.String)
	 */
	@Override
	public String[] findByValue(String searchString)
			throws ConfigurationException {
		if (null == em) {
			log.error("No EntityManager set!");
			throw new ConfigurationException("No EntityManager set!");
		}
		
		TypedQuery<AbstractConfigProperty> query = em.createQuery("select * from " + dataBaseEntityName + " dbconfig", AbstractConfigProperty.class);
		List<AbstractConfigProperty> all = query.getResultList();
		
		searchString = searchString.replace(".", "\\.");
		String regex = searchString.replace("*", ".*");
		regex = regex.replace("%", "\\w*");
		log.debug("Searching with regex: {}", regex);	
		Pattern pattern = Pattern.compile(regex);
		
		List<String> keyList = new ArrayList<String>();	
		Iterator<AbstractConfigProperty> keyIt;
		if (all != null) {
			keyIt = all.iterator();
			while(keyIt.hasNext()) {
				AbstractConfigProperty entry = keyIt.next();
				String value = entry.getValue();
				String key = entry.getKey();
				
				if(pattern.matcher(value).matches()) {
					keyList.add(key);
				}								
			}
		}
				
		String[] result = new String[keyList.size()];		
		return keyList.toArray(result);
			
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#synchronize()
	 */
	@Override
	public void synchronize() throws ConfigurationException {
		//INFO: no implementation required 
		
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#getName()
	 */
	@Override
	public String getName() {
		return "DatabaseConfiguration";
	}
	
	
	private AbstractConfigProperty getProperty(String key) {
		log.trace("Looking for configuration property for key '{}'.", key);
								
		AbstractConfigProperty result = em.find(appContext.getBean(AbstractConfigProperty.class).getClass(), key); 
		if (result != null) {
			log.trace("Found configuration property {}.", result);
		} else {
			log.debug("Unable to find configuration property for key '{}'.", key);
		}
		return result;
	}

	/* (non-Javadoc)
	 * @see at.gv.egiz.components.configuration.api.AbstractConfigurationImpl#deleteIds(java.lang.String)
	 */
	@Override
	@Transactional("transactionManager")
	public void deleteIds(String idSearch) throws ConfigurationException {
		String[] keyList = findConfigurationId(idSearch);
		for (String el : keyList) {
			deleteKey(el);
			
		}
	}
	
}