Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.joran.conditional;

import java.util.ArrayList;
import java.util.List;
import java.util.Stack;

import org.xml.sax.Attributes;

import ch.qos.logback.core.joran.action.Action;
import ch.qos.logback.core.joran.event.InPlayListener;
import ch.qos.logback.core.joran.event.SaxEvent;
import ch.qos.logback.core.joran.spi.ActionException;
import ch.qos.logback.core.joran.spi.InterpretationContext;

abstract public class ThenOrElseActionBase extends Action {

    Stack<ThenActionState> stateStack = new Stack<ThenActionState>();

    @Override
    public void begin(InterpretationContext ic, String name, Attributes attributes) throws ActionException {

        if (!weAreActive(ic))
            return;

        ThenActionState state = new ThenActionState();
        if (ic.isListenerListEmpty()) {
            ic.addInPlayListener(state);
            state.isRegistered = true;
        }
        stateStack.push(state);
    }

    boolean weAreActive(InterpretationContext ic) {
        Object o = ic.peekObject();
        if (!(o instanceof IfAction))
            return false;
        IfAction ifAction = (IfAction) o;
        return ifAction.isActive();
    }

    @Override
    public void end(InterpretationContext ic, String name) throws ActionException {
        if (!weAreActive(ic))
            return;

        ThenActionState state = stateStack.pop();
        if (state.isRegistered) {
            ic.removeInPlayListener(state);
            Object o = ic.peekObject();
            if (o instanceof IfAction) {
                IfAction ifAction = (IfAction) o;
                removeFirstAndLastFromList(state.eventList);
                registerEventList(ifAction, state.eventList);
            } else {
                throw new IllegalStateException("Missing IfAction on top of stack");
            }
        }
    }

    abstract void registerEventList(IfAction ifAction, List<SaxEvent> eventList);

    void removeFirstAndLastFromList(List<SaxEvent> eventList) {
        eventList.remove(0);
        eventList.remove(eventList.size() - 1);
    }

}

class ThenActionState implements InPlayListener {

    List<SaxEvent> eventList = new ArrayList<SaxEvent>();
    boolean isRegistered = false;

    public void inPlay(SaxEvent event) {
        eventList.add(event);
    }
}