package com.atlassian.sal.spring.component;
   
   import java.util.HashMap;
   import java.util.Map;
   
   import org.apache.commons.logging.Log;
   import org.apache.commons.logging.LogFactory;
   import org.springframework.beans.BeansException;
   import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
  import org.springframework.beans.factory.support.DefaultListableBeanFactory;
  import org.springframework.context.ApplicationContext;
  import org.springframework.context.ApplicationContextAware;
  import org.springframework.context.support.AbstractApplicationContext;
  import org.springframework.transaction.PlatformTransactionManager;
  import org.springframework.transaction.TransactionDefinition;
  import org.springframework.transaction.TransactionStatus;
  import org.springframework.transaction.support.DefaultTransactionDefinition;
  
  import com.atlassian.sal.spi.HostContextAccessor;
  
  /**
   * Implements the host context accessor for Spring environments
   */
  public class SpringHostContextAccessor implements HostContextAccessor, ApplicationContextAware
  {
      private ApplicationContext applicationContext;
      private final PlatformTransactionManager transactionManager;
      private static final Log log = LogFactory.getLog(SpringHostContextAccessor.class);
  
      public SpringHostContextAccessor(final PlatformTransactionManager transactionManager)
      {
          this.transactionManager = transactionManager;
      }
  
      @SuppressWarnings("unchecked")
  	public <T> Map<String, T> getComponentsOfType(final Class<T> iface)
      {
          try
  		{
          	return applicationContext.getBeansOfType(iface);
  		} catch (final RuntimeException ex)
  		{
  			// This exception will start occuring after removing bean from the context (eg: disabling plugin)
  			// until next restart of Confluence. See https://studio.atlassian.com/browse/JST-509
  			log.debug(ex,ex);
              final Map<String, T> results = new HashMap<String, T>();
              if (applicationContext instanceof AbstractApplicationContext)
              {
                  final AbstractApplicationContext abstractApplicationContext = (AbstractApplicationContext) applicationContext;
                  final ConfigurableListableBeanFactory beanFactory = abstractApplicationContext.getBeanFactory();
                  if (beanFactory instanceof DefaultListableBeanFactory)
                  {
                      final DefaultListableBeanFactory defaultListableBeanFactory = (DefaultListableBeanFactory) beanFactory;
                      final String[] beanDefinitionNames = defaultListableBeanFactory.getBeanDefinitionNames();
                      for (final String beanName : beanDefinitionNames)
  					{
                          try
                          {
                              final Object bean = defaultListableBeanFactory.getBean(beanName);
                              if (bean != null && iface.isAssignableFrom(bean.getClass()))
                              {
                                  results.put(beanName, (T) bean);
                              }
                          } catch (final BeansException e)
                          {
                              // ignore
                          }
                      }
                  }
              }
              return results;
          }
  
  
  
      }
  
      public Object doInTransaction(final HostTransactionCallback callback)
      {
          final org.springframework.transaction.support.TransactionTemplate txTemplate =
                  new org.springframework.transaction.support.TransactionTemplate(transactionManager, getTransactionDefinition());
          return txTemplate.execute(new org.springframework.transaction.support.TransactionCallback()
          {
              public Object doInTransaction(final TransactionStatus transactionStatus)
              {
                  try
                  {
                      return callback.doInTransaction();
                  }
                  catch (final RuntimeException e)
                  {
                      //rollback if something weird happened.
                      transactionStatus.setRollbackOnly();
                      throw e;
                  }
              }
          });
      }
  
     public void setApplicationContext(final ApplicationContext applicationContext) throws BeansException
     {
         this.applicationContext = applicationContext;
     }
 
     protected DefaultTransactionDefinition getTransactionDefinition()
     {
         final DefaultTransactionDefinition def = new DefaultTransactionDefinition();
         def.setName("PluginReadWriteTx");
         def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRED);
         def.setReadOnly(false);
         return def;
     }
 
 
 
 }