package pl.matsuo.core.web.scope;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   import org.springframework.beans.factory.ObjectFactory;
   import org.springframework.beans.factory.config.Scope;
   import org.springframework.core.NamedThreadLocal;
   import org.springframework.web.context.request.AbstractRequestAttributesScope;
   import org.springframework.web.context.request.RequestAttributes;
  import org.springframework.web.context.request.RequestContextHolder;
  
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Session scope modification that provides bean even outside of http request processing.
   *
   * Created by marek on 19.07.14.
   */
  public class WideSessionScope extends AbstractRequestAttributesScope implements Scope {
    private static final Logger logger = LoggerFactory.getLogger(WideSessionScope.class);
  
  
    protected Map<String, ThreadLocal<Object>> objectHolders = new HashMap<>();
  
  
    @Override
    protected int getScope() {
      // constant higher than values from RequestAttributes.
      return 13;
    }
  
  
    @Override
    public String getConversationId() {
      try {
        return RequestContextHolder.currentRequestAttributes().getSessionId();
      } catch (IllegalStateException e) {
        logger.debug("outside web session");
        e.printStackTrace();
        return "non_web_";
      }
    }
  
  
    @Override
    public Object get(String name, ObjectFactory<?> objectFactory) {
      try {
        Object mutex = RequestContextHolder.currentRequestAttributes().getSessionMutex();
        synchronized (mutex) {
          return super.get(name, objectFactory);
        }
      } catch (IllegalStateException e) {
        logger.debug("outside web session");
        ThreadLocal<Object> objectHolder = objectHolders.get(name);
        if (objectHolder == null) {
          objectHolders.put(name, new NamedThreadLocal<>("wideScopeObjectHolder_" + name));
          objectHolder = objectHolders.get(name);
        }
  
        if (objectHolder.get() == null) {
          objectHolder.set(objectFactory.getObject());
        }
        return objectHolder.get();
      }
    }
  
  
    @Override
    public Object remove(String name) {
      try {
        Object mutex = RequestContextHolder.currentRequestAttributes().getSessionMutex();
        synchronized (mutex) {
          return super.remove(name);
        }
      } catch (IllegalStateException e) {
        logger.debug("outside web session");
        Object object = objectHolders.get(name).get();
        objectHolders.get(name).set(null);
        return object;
      }
    }
  
  
    @Override
    public void registerDestructionCallback(String name, Runnable callback) {
      try {
        logger.debug("outside web session");
        RequestAttributes attributes = RequestContextHolder.currentRequestAttributes();
        attributes.registerDestructionCallback(name, callback, getScope());
      } catch (IllegalStateException e) {
  
      }
    }
  }