#!/usr/bin/env python

#
# Implementation for experiment session controller.
#

import os
import time

from dm.common.objects.experiment import Experiment
from dm.common.objects.dmObjectManager import DmObjectManager
from dm.common.exceptions.invalidRequest import InvalidRequest
from dm.common.utility.osUtility import OsUtility
from dm.common.objects.observedFile import ObservedFile
from dm.common.processing.fileProcessingManager import FileProcessingManager
from dm.ds_web_service.api.dsRestApiFactory import DsRestApiFactory
from experimentTracker import ExperimentTracker
from fileSystemObserver import FileSystemObserver

class ExperimentSessionControllerImpl(DmObjectManager):
    """ Experiment session controller implementation class. """

    def __init__(self):
        DmObjectManager.__init__(self)
        self.dsExperimentApi = DsRestApiFactory.getExperimentRestApi()

    def startDaq(self, experimentName, dataDirectory, daqInfo):
        if not os.path.exists(dataDirectory):
           os.makedirs(dataDirectory)
        if daqInfo is None:
           daqInfo={}
	   daqInfo['experimentName'] = experimentName
	   daqInfo['dataDirectory'] = dataDirectory
        experiment = ExperimentTracker.getInstance().get(experimentName)
        if experiment is not None:
            oldDaqInfo = experiment.get('daqInfo')
            if oldDaqInfo.get('daqEndTime') is None:
                raise InvalidRequest('DAQ for experiment %s is already active in directory %s.' % (experimentName,oldDaqInfo.get('dataDirectory')))

        experiment = self.dsExperimentApi.getExperimentByName(experimentName)
        storageDirectory = experiment.get('storageDirectory')
        if storageDirectory is None:
            raise InvalidRequest('Experiment %s has not been started.' % experimentName)
        startTime = time.time()
        daqInfo['daqStartTime'] = startTime
        experiment['daqInfo'] = daqInfo
        self.logger.debug('Starting DAQ %s' % daqInfo)
        FileSystemObserver.getInstance().startObservingPath(dataDirectory, experiment)
        ExperimentTracker.getInstance().put(experimentName, experiment)
        return experiment

    def stopDaq(self, experimentName):
        experiment = ExperimentTracker.getInstance().get(experimentName)
        if experiment is not None:
            daqInfo = experiment.get('daqInfo')
        if experiment is None or daqInfo.get('daqEndTime') is not None:
            raise InvalidRequest('Experiment %s is not active.' % experimentName)
        dataDirectory = daqInfo.get('dataDirectory')
        daqInfo['daqEndTime'] = time.time()
        FileSystemObserver.getInstance().stopObservingPath(dataDirectory, experiment)
        return experiment

    def upload(self, daqInfo):
        experimentName = daqInfo.get('experimentName')
        experiment = self.dsExperimentApi.getExperimentByName(experimentName)
        experiment['daqInfo'] = daqInfo
        storageDirectory = experiment.get('storageDirectory')
        if storageDirectory is None:
            raise InvalidRequest('Experiment %s has not been started.' % experimentName)
        dataDirectory = daqInfo.get('dataDirectory')
        filePaths = OsUtility.findFiles(dataDirectory)
        fileProcessingManager = FileProcessingManager.getInstance()
        for filePath in filePaths:
            fileInfo = ObservedFile(filePath=filePath, dataDirectory=dataDirectory, experiment=experiment)
            fileProcessingManager.processFile(fileInfo)
        ExperimentTracker.getInstance().put(experimentName, experiment)
        return experiment