package dao;

import java.util.HashMap;
import java.util.Map;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;

import dao.entities.DMPDaoImpl;
import dao.entities.DMPProfileDaoImpl;
import dao.entities.DMPResearcherDaoImpl;
import dao.entities.DataRepositoryDaoImpl;
import dao.entities.DatasetDaoImpl;
import dao.entities.DatasetProfileDaoImpl;
import dao.entities.DatasetProfileRulesetDaoImpl;
import dao.entities.DatasetProfileViewstyleDaoImpl;
import dao.entities.DatasetRegistryDaoImpl;
import dao.entities.DatasetServiceDaoImpl;
import dao.entities.OrganisationDaoImpl;
import dao.entities.ProjectDaoImpl;
import dao.entities.RegistryDaoImpl;
import dao.entities.ResearcherDaoImpl;
import dao.entities.ServiceDaoImpl;
import entities.DMP;
import entities.DMPProfile;
import entities.DMPResearcher;
import entities.DataRepository;
import entities.Dataset;
import entities.DatasetProfile;
import entities.DatasetProfileRuleset;
import entities.DatasetProfileViewstyle;
import entities.DatasetRegistry;
import entities.DatasetService;
import entities.Organisation;
import entities.Project;
import entities.Registry;
import entities.Researcher;
import entities.Service;


/**
 * A DAO factory for Spring managed environment
 */
public class SpringJpaDaoFactory implements DaoFactory
{
	public static class SpringApplicationContext implements ApplicationContextAware {

		  private static ApplicationContext CONTEXT;

		  /**
		   * This method is called from within the ApplicationContext once it is 
		   * done starting up, it will stick a reference to itself into this bean.
		   * @param context a reference to the ApplicationContext.
		   */
		  public void setApplicationContext(ApplicationContext context) throws BeansException {
		    CONTEXT = context;
		  }

		  /**
		   * This is about the same as context.getBean("beanName"), except it has its
		   * own static handle to the Spring context, so calling this method statically
		   * will give access to the beans by name in the Spring application context.
		   * As in the context.getBean("beanName") call, the caller must cast to the
		   * appropriate target class. If the bean does not exist, then a Runtime error
		   * will be thrown.
		   * @param beanName the name of the bean to get.
		   * @return an Object reference to the named bean.
		   */
		  public static Object getBean(String beanName) {
		    return CONTEXT.getBean(beanName);
		  }
	}
	
	private static String persistenceUnit = null;
	private static Map<String, String> daoImpls = null;
	
	public static void setPersistenceContext(String persistenceUnit)
	{
		SpringJpaDaoFactory.persistenceUnit = persistenceUnit;
	}
	
	private static String getBeanName(String className)
	{
		return Character.toLowerCase(className.charAt(0)) + 
				(className.length() > 1 ? className.substring(1) : "");
	}
	private static void populateMappings()
	{
		daoImpls = new HashMap<String, String>();
		daoImpls.put(DataRepository.class.getName(), getBeanName(DataRepositoryDaoImpl.class.getSimpleName()));
		daoImpls.put(Dataset.class.getName(), getBeanName(DatasetDaoImpl.class.getSimpleName()));
		daoImpls.put(DatasetProfile.class.getName(), getBeanName(DatasetProfileDaoImpl.class.getSimpleName()));
		daoImpls.put(DatasetProfileRuleset.class.getName(), getBeanName(DatasetProfileRulesetDaoImpl.class.getSimpleName()));
		daoImpls.put(DatasetProfileViewstyle.class.getName(), getBeanName(DatasetProfileViewstyleDaoImpl.class.getSimpleName()));
		daoImpls.put(DatasetRegistry.class.getName(), getBeanName(DatasetRegistryDaoImpl.class.getSimpleName()));
		daoImpls.put(DatasetService.class.getName(), getBeanName(DatasetServiceDaoImpl.class.getSimpleName()));
		daoImpls.put(DMP.class.getName(), getBeanName(DMPDaoImpl.class.getSimpleName()));
		daoImpls.put(DMPProfile.class.getName(), getBeanName(DMPProfileDaoImpl.class.getSimpleName()));
		daoImpls.put(DMPResearcher.class.getName(), getBeanName(DMPResearcherDaoImpl.class.getSimpleName()));
		daoImpls.put(Organisation.class.getName(), getBeanName(OrganisationDaoImpl.class.getSimpleName()));
		daoImpls.put(Project.class.getName(), getBeanName(ProjectDaoImpl.class.getSimpleName()));
		daoImpls.put(Registry.class.getName(), getBeanName(RegistryDaoImpl.class.getSimpleName()));
		daoImpls.put(Researcher.class.getName(), getBeanName(ResearcherDaoImpl.class.getSimpleName()));
		daoImpls.put(Service.class.getName(), getBeanName(ServiceDaoImpl.class.getSimpleName()));
	}
	
	@SuppressWarnings("rawtypes")
	public Dao getDao(Class<?> type) throws Exception
	{
		if(daoImpls == null) populateMappings();
		return (Dao)SpringApplicationContext.getBean(daoImpls.get(type.getName()));
	}

	public void overrideMappings(Map<String, String> mappings)
	{
		populateMappings();
		daoImpls.putAll(mappings);
	}
}