/*
 *  Copyright 2014 Anyware Services
 *
 *  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 org.ametys.cms.alerts;

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.List;
import java.util.Timer;
import java.util.TimerTask;

import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.ContextException;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.LogEnabled;
import org.apache.avalon.framework.logger.Logger;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.cocoon.environment.Request;
import org.apache.commons.lang.StringUtils;

import org.ametys.runtime.config.Config;

/**
 * Alerts scheduler: launches a cron which sends the alerts each night.
 */
public class AlertScheduler extends TimerTask implements Initializable, LogEnabled, Serviceable, Disposable, Contextualizable, Configurable, Component
{
    /** The Avalon role */
    public static final String ROLE = AlertScheduler.class.getName();
    
    /** The service manager. */
    protected ServiceManager _manager;
    
    /** The component configuration. */
    protected Configuration _configuration;
    
    /** The avalon context. */
    protected Context _context;
    
    /** The logger. */
    protected Logger _logger;
    
    /** The timer. */
    protected Timer _timer;
    
    @Override
    public void service(ServiceManager manager) throws ServiceException
    {
        _manager = manager;
    }
    
    @Override
    public void contextualize(Context context) throws ContextException
    {
        _context = context;
    }
    
    @Override
    public void configure(Configuration configuration) throws ConfigurationException
    {
        _configuration = configuration;
    }
    
    @Override
    public void enableLogging(Logger logger)
    {
        _logger = logger;
    }
    
    @Override
    public void initialize() throws Exception
    {
        if (!Config.getInstance().getValueAsBoolean("remind.content.enabled"))
        {
            return;
        }
         
        if (_logger.isDebugEnabled())
        {
            _logger.debug("Initializing the alert scheduler...");
        }
        
        // Schedule a timer to run each night.
        String hourStr = Config.getInstance().getValueAsString("alerts.scheduler.hour");
        int hour = 0;
        int minute = 0;
        if (StringUtils.isNotEmpty(hourStr) && hourStr.indexOf(':') > 0)
        {
            String[] hourArray = StringUtils.split(hourStr, ':');
            hour = Integer.parseInt(hourArray[0]);
            minute = Integer.parseInt(hourArray[1]);
        }
        
        GregorianCalendar calendar = new GregorianCalendar();
        calendar.set(Calendar.AM_PM, hour < 12 ? Calendar.AM : Calendar.PM);
        calendar.set(Calendar.HOUR, hour % 12);
        calendar.set(Calendar.MINUTE, minute);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        
        // Each day.
        long period = 86400000;
        Date firstTime = calendar.getTime();

        Date now = new Date();

        // If the given time today is past, schedule for tomorrow.
        if (firstTime.compareTo(now) < 0)
        {
            calendar.add(Calendar.DAY_OF_MONTH, 1);
            firstTime = calendar.getTime();
        }
        
        if (_logger.isInfoEnabled())
        {
            _logger.info("Alerts scheduler: the alerts engine will run each day, starting " + firstTime.toString());
        }
        
        _timer = new Timer("AlertsScheduler", true);
        _timer.schedule(this, firstTime, period);
    }
    
    @Override
    public void run()
    {
        AlertEngine alertEngine = new AlertEngine();
        
        try
        {
            // Initialize and configure the engine.
            alertEngine.initialize(_manager, _context);
            alertEngine.configure(_configuration);
        }
        catch (Exception e)
        {
            throw new RuntimeException("Unable to initialize the alerts engine", e);
        }
        
        // The thread will be started as daemon, as the scheduler is marked daemon itself.
        new Thread(alertEngine, "AlertEngine").start();
    }
    
    /**
     * Run the scheduler to send instant alerts on contents
     * @param contentIds The ids of concerned contents
     * @param message the message to send to authorized users
     */
    public void sendInstantAlerts (List<String> contentIds, String message)
    {
        AlertEngine alertEngine = new AlertEngine(contentIds, message);
        
        try
        {
            // Initialize and configure the engine.
            alertEngine.initialize(_manager, _context);
            alertEngine.configure(_configuration);
        }
        catch (Exception e)
        {
            throw new RuntimeException("Unable to initialize the alerts engine", e);
        }
        
        // The thread will be started as daemon, as the scheduler is marked daemon itself.
        new Thread(alertEngine, "AlertEngine").start();
    }
    
    /**
     * Get the request URI.
     * @param request the request object.
     * @return the full request URI.
     */
    protected String _getRequestURI(Request request)
    {
        StringBuilder sb = new StringBuilder();
        sb.append(request.getScheme());
        sb.append("://");
        sb.append(request.getServerName());
        
        // Construire une uri sans :80 en http et sans :443 en https
        if (request.isSecure())
        {
            if (request.getServerPort() != 443)
            {
                sb.append(":");
                sb.append(request.getServerPort());
            }
        }
        else
        {
            if (request.getServerPort() != 80)
            {
                sb.append(":");
                sb.append(request.getServerPort());
            }
        }
        
        sb.append(request.getContextPath());
        
        return sb.toString();
    }
        
    @Override
    public void dispose()
    {
        _context = null;
        _logger = null;
        _manager = null;
        _configuration = null;
        
        cancel();
        if (_timer != null)
        {
            _timer.cancel();
            _timer = null;
        }
    }
    
}