import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.faces.context.FacesContext;
import org.jboss.seam.ScopeType;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import org.jboss.seam.annotations.Logger;
import org.jboss.seam.annotations.Observer;
import org.jboss.seam.annotations.Scope;
import org.jboss.seam.log.Log;

@Scope(ScopeType.EVENT)
@Name("conversationTimeoutWorkaround")
public class ConversationTimeoutWorkaround {

    private List<String> timeoutIds = new ArrayList<String>();

    @Logger 
    private Log log;

    @In(required=false)
    private FacesContext facesContext;

    @Observer("org.jboss.seam.conversationTimeout")
    public void conversationTimeout(String id) {
        if (log.isDebugEnabled()) {
            log.debug("conversationTimeout(): id: " + id + ", this: " + this);
        }
        timeoutIds.add(id);
    }

    @Observer("org.jboss.seam.preDestroyContext.EVENT")
    public void cleanOrphan() {
        if (facesContext == null || timeoutIds.isEmpty()) {
            return;
        }
        for (Iterator<String> it = timeoutIds.iterator(); it.hasNext(); ) {
            String id = it.next();
            Map<String, Object> sessionMap = facesContext.getExternalContext().getSessionMap();
            removeIfExists(sessionMap, ScopeType.CONVERSATION.getPrefix() + '#' + id + "$org.jboss.seam.persistence.persistenceContexts");
            removeIfExists(sessionMap, ScopeType.CONVERSATION.getPrefix() + '#' + id + "$org.jboss.seam.bpm.businessProcess");
        }
        timeoutIds.clear();
    }

    private void removeIfExists(Map<String, Object> sessionMap, String key) {
        if (log.isDebugEnabled()) {
            log.debug("cleanOrphan(): key: " + key + ", this: " + this);
            log.debug("sessionMap: " + sessionMap);
        }
        if (sessionMap.containsKey(key)) {
            sessionMap.remove(key);
            if (log.isDebugEnabled()) {
                log.debug("removed, key: " + key);
            }
        }
    }
}