<?php
// Copyright (C) 2010-2016 Combodo SARL
//
//   This file is part of iTop.
//
//   iTop is free software; you can redistribute it and/or modify	
//   it under the terms of the GNU Affero General Public License as published by
//   the Free Software Foundation, either version 3 of the License, or
//   (at your option) any later version.
//
//   iTop is distributed in the hope that it will be useful,
//   but WITHOUT ANY WARRANTY; without even the implied warranty of
//   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//   GNU Affero General Public License for more details.
//
//   You should have received a copy of the GNU Affero General Public License
//   along with iTop. If not, see <http://www.gnu.org/licenses/>

/**
 * Heart beat of the application (process asynchron tasks such as broadcasting email)
 *
 * @copyright   Copyright (C) 2010-2016 Combodo SARL
 * @license     http://opensource.org/licenses/AGPL-3.0
 */

if (!defined('__DIR__')) define('__DIR__', dirname(__FILE__));
require_once(__DIR__.'/../approot.inc.php');
require_once(APPROOT.'/application/application.inc.php');
require_once(APPROOT.'/application/nicewebpage.class.inc.php');
require_once(APPROOT.'/application/webpage.class.inc.php');
require_once(APPROOT.'/application/clipage.class.inc.php');
require_once(APPROOT.'/core/background.inc.php');

$sConfigFile = APPCONF.ITOP_DEFAULT_ENV.'/'.ITOP_CONFIG_FILE;
if (!file_exists($sConfigFile))
{
	echo "iTop is not yet installed. Exiting...\n";
	exit(-1);
}

require_once(APPROOT.'/application/startup.inc.php');

$oCtx = new ContextTag('CRON');

function ReadMandatoryParam($oP, $sParam, $sSanitizationFilter = 'parameter')
{
	$sValue = utils::ReadParam($sParam, null, true /* Allow CLI */, $sSanitizationFilter);
	if (is_null($sValue))
	{
		$oP->p("ERROR: Missing argument '$sParam'\n");
		UsageAndExit($oP);
	}
	return trim($sValue);
}

function UsageAndExit($oP)
{
	$bModeCLI = utils::IsModeCLI();

	if ($bModeCLI)
	{
		$oP->p("USAGE:\n");
		$oP->p("php cron.php --auth_user=<login> --auth_pwd=<password> [--param_file=<file>] [--verbose=1] [--debug=1] [--status_only=1]\n");		
	}
	else
	{
		$oP->p("Optional parameters: verbose, param_file, status_only\n");		
	}
	$oP->output();
	exit -2;
}

function RunTask($oProcess, BackgroundTask $oTask, $oStartDate, $iTimeLimit)
{
	$oNow = new DateTime();
	$fStart = microtime(true);
	try
	{
		$sMessage = $oProcess->Process($iTimeLimit);
	}
	catch(Exception $e)
	{
		$sMessage = 'Processing failed with message: '.$e->getMessage();
	}
	$fDuration = microtime(true) - $fStart;
	if ($oTask->Get('total_exec_count') == 0)
	{
		// First execution
		$oTask->Set('first_run_date', $oNow->format('Y-m-d H:i:s'));
	}
	$oTask->ComputeDurations($fDuration); // does increment the counter and compute statistics
	$oTask->Set('latest_run_date', $oNow->format('Y-m-d H:i:s'));

	$oRefClass = new ReflectionClass(get_class($oProcess));
	if ($oRefClass->implementsInterface('iScheduledProcess'))
	{
		// Schedules process do repeat at specific moments
		$oPlannedStart = $oProcess->GetNextOccurrence();
	}
	else
	{
		// Background processes do repeat periodically
		$oPlannedStart = new DateTime($oTask->Get('latest_run_date'));
		// Let's assume that the task was started exactly when planned so that the schedule does no shift each time
		// this allows to schedule a task everyday "around" 11:30PM for example
		$oPlannedStart->modify('+'.$oProcess->GetPeriodicity().' seconds');
		$oEnd = new DateTime();
		if ($oPlannedStart->format('U') < $oEnd->format('U'))
		{
			// Huh, next planned start is already in the past, shift it of the periodicity !
			$oPlannedStart = $oEnd->modify('+'.$oProcess->GetPeriodicity().' seconds');
		}
	}

	$oTask->Set('next_run_date', $oPlannedStart->format('Y-m-d H:i:s'));
	$oTask->DBUpdate();
	return $sMessage;
}

function CronExec($oP, $aProcesses, $bVerbose)
{
	$iStarted = time();
	$iMaxDuration = MetaModel::GetConfig()->Get('cron_max_execution_time');
	$iTimeLimit = $iStarted + $iMaxDuration;
	
	if ($bVerbose)
	{
		$oP->p("Planned duration = $iMaxDuration seconds");
	}

	// Reset the next planned execution to take into account new settings
	$oSearch = new DBObjectSearch('BackgroundTask');
	$oTasks = new DBObjectSet($oSearch);
	while($oTask = $oTasks->Fetch())
	{
		$sTaskClass = $oTask->Get('class_name');
		$oRefClass = new ReflectionClass($sTaskClass);
		$oNow = new DateTime();
		if($oRefClass->implementsInterface('iScheduledProcess') && (($oTask->Get('status') != 'active') || ($oTask->Get('next_run_date') > $oNow->format('Y-m-d H:i:s'))))
		{
			if ($bVerbose)
			{
				$oP->p("Resetting the next run date for $sTaskClass");
			}
			$oProcess = $aProcesses[$sTaskClass];
			$oNextOcc = $oProcess->GetNextOccurrence();
			$oTask->Set('next_run_date', $oNextOcc->format('Y-m-d H:i:s'));
			$oTask->DBUpdate();
		}
	}

	$iCronSleep = MetaModel::GetConfig()->Get('cron_sleep');
	
	$oSearch = new DBObjectSearch('BackgroundTask');
	while (time() < $iTimeLimit)
	{
		$oTasks = new DBObjectSet($oSearch);
		$aTasks = array();
		while($oTask = $oTasks->Fetch())
		{
			$aTasks[$oTask->Get('class_name')] = $oTask;
		}
		foreach ($aProcesses as $oProcess)
		{
			$sTaskClass = get_class($oProcess);
			$oNow = new DateTime();
			if (!array_key_exists($sTaskClass, $aTasks))
			{
				// New entry, let's create a new BackgroundTask record, and plan the first execution
				$oTask = new BackgroundTask();
				$oTask->Set('class_name', get_class($oProcess));
				$oTask->Set('total_exec_count', 0);
				$oTask->Set('min_run_duration', 99999.999);
				$oTask->Set('max_run_duration', 0);
				$oTask->Set('average_run_duration', 0);
				$oRefClass = new ReflectionClass($sTaskClass);
				if ($oRefClass->implementsInterface('iScheduledProcess'))
				{
					$oNextOcc = $oProcess->GetNextOccurrence();
					$oTask->Set('next_run_date', $oNextOcc->format('Y-m-d H:i:s'));
				}
				else
				{
					// Background processes do start asap, i.e. "now"
					$oTask->Set('next_run_date', $oNow->format('Y-m-d H:i:s'));
				}
				if ($bVerbose)
				{
					$oP->p('Creating record for: '.$sTaskClass);
					$oP->p('First execution planned at: '.$oTask->Get('next_run_date'));
				}
				$oTask->DBInsert();
				$aTasks[$oTask->Get('class_name')] = $oTask;
			}

			if( ($aTasks[$sTaskClass]->Get('status') == 'active') && ($aTasks[$sTaskClass]->Get('next_run_date') <= $oNow->format('Y-m-d H:i:s')))
			{
				// Run the task and record its next run time
				if ($bVerbose)
				{
					$oP->p(">> === ".$oNow->format('Y-m-d H:i:s').sprintf(" Starting:%-'=40s", ' '.$sTaskClass.' '));
				}
				$sMessage = RunTask($oProcess, $aTasks[$sTaskClass], $oNow, $iTimeLimit);
				if ($bVerbose)
				{
					if(!empty($sMessage))
					{
						$oP->p("$sTaskClass: $sMessage");
					}
					$oEnd = new DateTime();
					$oP->p("<< === ".$oEnd->format('Y-m-d H:i:s').sprintf(" End of:  %-'=40s", ' '.$sTaskClass.' '));
				}
			}
			else 
			{
				// will run later
				if (($aTasks[$sTaskClass]->Get('status') == 'active') && $bVerbose)
				{
					$oP->p("Skipping asynchronous task: $sTaskClass until ".$aTasks[$sTaskClass]->Get('next_run_date'));
				}
			}
		}
		if ($bVerbose)
		{
			$oP->p("Sleeping");
		}
		sleep($iCronSleep);
	}
	if ($bVerbose)
	{
		$oP->p("Reached normal execution time limit (exceeded by ".(time()-$iTimeLimit)."s)");
	}
}

function DisplayStatus($oP)
{
	$oSearch = new DBObjectSearch('BackgroundTask');
	$oTasks = new DBObjectSet($oSearch);
	$oP->p('+---------------------------+---------+---------------------+---------------------+--------+-----------+');
	$oP->p('| Task Class                | Status  | Last Run            | Next Run            | Nb Run | Avg. Dur. |');
	$oP->p('+---------------------------+---------+---------------------+---------------------+--------+-----------+');
	while($oTask = $oTasks->Fetch())
	{
		$sTaskName = $oTask->Get('class_name');
		$sStatus = $oTask->Get('status');
		$sLastRunDate = $oTask->Get('latest_run_date');
		$sNextRunDate = $oTask->Get('next_run_date');
		$iNbRun = (int)$oTask->Get('total_exec_count');
		$sAverageRunTime = $oTask->Get('average_run_duration');
		$oP->p(sprintf('| %1$-25.25s | %2$-7s | %3$-19s | %4$-19s | %5$6d | %6$7s s |', $sTaskName, $sStatus, $sLastRunDate, $sNextRunDate, $iNbRun, $sAverageRunTime));
	}	
	$oP->p('+---------------------------+---------+---------------------+---------------------+--------+-----------+');
}

////////////////////////////////////////////////////////////////////////////////
//
// Main
//

set_time_limit(0); // Some background actions may really take long to finish (like backup)

if (utils::IsModeCLI())
{
	$oP = new CLIPage("iTop - CRON");
}
else
{
	$oP = new WebPage("iTop - CRON");
}

try
{
	utils::UseParamFile();
}
catch(Exception $e)
{
	$oP->p("Error: ".$e->GetMessage());
	$oP->output();
	exit -2;
}

if (utils::IsModeCLI())
{
	// Next steps:
	//   specific arguments: 'csvfile'
	//   
	$sAuthUser = ReadMandatoryParam($oP, 'auth_user', 'raw_data');
	$sAuthPwd = ReadMandatoryParam($oP, 'auth_pwd', 'raw_data');
	if (UserRights::CheckCredentials($sAuthUser, $sAuthPwd))
	{
		UserRights::Login($sAuthUser); // Login & set the user's language
	}
	else
	{
		$oP->p("Access wrong credentials ('$sAuthUser')");
		$oP->output();
		exit -1;
	}
}
else
{
	$_SESSION['login_mode'] = 'basic';
	require_once(APPROOT.'/application/loginwebpage.class.inc.php');
	LoginWebPage::DoLogin(); // Check user rights and prompt if needed
}

if (!UserRights::IsAdministrator())
{
	$oP->p("Access restricted to administrators");
	$oP->Output();
	exit -1;
}

// Enumerate classes implementing BackgroundProcess
//
$aProcesses = array();
foreach(get_declared_classes() as $sPHPClass)
{
	$oRefClass = new ReflectionClass($sPHPClass);
	$oExtensionInstance = null;
	if ($oRefClass->implementsInterface('iProcess'))
	{
		if (is_null($oExtensionInstance))
		{
			$oExecInstance = new $sPHPClass;
		}
		$aProcesses[$sPHPClass] = $oExecInstance;
	}
}


$bVerbose = utils::ReadParam('verbose', false, true /* Allow CLI */);
$bDebug = utils::ReadParam('debug', false, true /* Allow CLI */);

if ($bVerbose)
{
	$aDisplayProcesses = array();
	foreach ($aProcesses as $oExecInstance)
	{
		$aDisplayProcesses[] = get_class($oExecInstance);
	}
	$sDisplayProcesses = implode(', ', $aDisplayProcesses);
	$oP->p("Background processes: ".$sDisplayProcesses);
}
if (utils::ReadParam('status_only', false, true /* Allow CLI */))
{
	// Display status and exit
	DisplayStatus($oP);
	exit(0);
}

require_once(APPROOT.'core/mutex.class.inc.php');
$oP->p("Starting: ".time().' ('.date('Y-m-d H:i:s').')');

try
{
	$oConfig = utils::GetConfig();
	$oMutex = new iTopMutex('cron');
	if ($oMutex->TryLock())
	{
		// Note: testing this now in case some of the background processes forces the read-only mode for a while
		//       in that case it is better to exit with the check on reentrance (mutex)
		if (!MetaModel::DBHasAccess(ACCESS_ADMIN_WRITE))
		{
			$oP->p("A database maintenance is ongoing (read-only mode even for admins).");
			$oP->Output();
			exit -1;
		}

		CronExec($oP, $aProcesses, $bVerbose);

		$oMutex->Unlock();
	}
	else
	{
		// Exit silently
		$oP->p("Already running...");
	}
}
catch (Exception $e)
{
	$oP->p("ERROR: '".$e->getMessage()."'");
	if ($bDebug)
	{
		// Might contain verb parameters such a password...
		$oP->p($e->getTraceAsString());
	}
}

$oP->p("Exiting: ".time().' ('.date('Y-m-d H:i:s').')');

$oP->Output();
?>