NotTrigger.java

/*
 * Copyright 2015 Collective, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 */
package com.collective.celos.trigger;


import com.collective.celos.ScheduledTime;
import com.collective.celos.database.StateDatabaseConnection;
import com.collective.celos.Util;

import java.util.Collections;

/**
 * Trigger that takes a nested trigger and does a logical NOT.
 */
public class NotTrigger extends Trigger {

    private final Trigger trigger;
    
    public NotTrigger(Trigger trigger) throws Exception {
        this.trigger = Util.requireNonNull(trigger);
    }

    @Override
    public TriggerStatus getTriggerStatus(StateDatabaseConnection connection, ScheduledTime now, ScheduledTime scheduledTime) throws Exception {
        TriggerStatus status = trigger.getTriggerStatus(connection, now, scheduledTime);
        boolean ready = !status.isReady();
        return makeTriggerStatus(ready, humanReadableDescription(ready), Collections.singletonList(status));
    }

    private String humanReadableDescription(boolean ready) {
        if (ready) {
            return "Ready, nested trigger isn't ready";
        } else {
            return "Not ready, nested trigger is ready";
        }
    }

    public Trigger getTrigger() {
        return trigger;
    }

}