#!/usr/bin/env python

import threading
import time
import os
import uuid
import glob
import copy

from dm.common.constants import dmProcessingStatus
from dm.common.exceptions.invalidRequest import InvalidRequest
from dm.common.objects.childProcess import ChildProcess
from dm.common.objects.processingJob import ProcessingJob
from dm.common.utility.loggingManager import LoggingManager
from dm.common.utility.configurationManager import ConfigurationManager
from dm.common.utility.objectUtility import ObjectUtility
from dm.common.utility.valueUtility import ValueUtility
from dm.common.utility.timeUtility import TimeUtility
from dm.common.utility.threadingUtility import ThreadingUtility
from dm.common.utility.timeBasedProcessingQueue import TimeBasedProcessingQueue
from dm.common.utility.singleton import Singleton
from executionThread import ExecutionThread
from processingJobTracker import ProcessingJobTracker

class ExecutionManager(Singleton):

    CONFIG_SECTION_NAME = 'ExecutionManager'
    NUMBER_OF_EXECUTION_THREADS_KEY = 'numberofexecutionthreads'
    DEFAULT_NUMBER_OF_EXECUTION_THREADS = 3

    FILE_PATH_LIST_KEY = 'filePathList'
    FILE_PATH_PATTERN_KEY = 'filePathPattern'
    FILE_QUERY_DICT_KEY = 'fileQueryDict'

    PROCESSING_JOB_START_DELAY_IN_SECONDS = 10
    MAX_NUMBER_OF_CHILD_PROCESSES = 10
    CHILD_PROCESSES_EVENT_TIMEOUT_IN_SECONDS = 10

    # Singleton.
    __instanceLock = threading.RLock()
    __instance = None

    def __init__(self):
        ExecutionManager.__instanceLock.acquire()
        try:
            if ExecutionManager.__instance:
                return
            ExecutionManager.__instance = self
            self.logger = LoggingManager.getInstance().getLogger(self.__class__.__name__)

            self.logger.debug('Initializing')
            self.lock = threading.RLock()
            self.executionThreadDict = {}
            self.eventFlag = threading.Event()
            self.executionQueue = TimeBasedProcessingQueue()
            self.__configure()
            self.logger.debug('Initialization complete')
        finally:
            ExecutionManager.__instanceLock.release()

    def __configure(self):
        cm = ConfigurationManager.getInstance()
        configItems = cm.getConfigItems(ExecutionManager.CONFIG_SECTION_NAME)
        self.logger.debug('Got config items: %s' % configItems)
        self.nExecutionThreads = int(cm.getConfigOption(ExecutionManager.CONFIG_SECTION_NAME, ExecutionManager.NUMBER_OF_EXECUTION_THREADS_KEY, ExecutionManager.DEFAULT_NUMBER_OF_EXECUTION_THREADS))

    def resolveFileSpec(self, processingJob):
        if processingJob.has_key('filePathList'):
            return self.resolveFilePathList(processingJob)
        elif processingJob.has_key('filePathPattern'):
            return self.resolveFilePathPattern(processingJob)
        elif processingJob.has_key('fileQueryDict'):
            return self.resolveFileQueryDict(processingJob)
        else:
            raise InvalidRequest('Invalid input file specification.')

    def resolveFilePathList(self, processingJob):
        return processingJob.get('filePathList')

    def resolveFilePathPattern(self, processingJob):
        if not processingJob.has_key('filePathList'):
             globPattern = processingJob.get('filePathPattern')
             dataDir = processingJob.get('dataDir')
             currentDir = os.getcwd()
             if dataDir:
                 os.chdir(dataDir)     
             processingJob['filePathList'] = glob.glob(globPattern)
             os.chdir(currentDir)     
        return processingJob.get('filePathList', [])

    def resolveFileQueryDict(self, processingJob):
        return []

    def startProcessingJob(self, processingJob):
        workflow = processingJob.get('workflow')
        self.logger.debug('Submitted processing job for workflow %s' % workflow.get('name'))
        jobId = str(uuid.uuid4())
        processingJob['id'] =  jobId
        startTime = time.time()
        processingJob['startTime'] = startTime
        processingJob['startTimestamp'] = TimeUtility.formatLocalTimestamp(startTime)

        processingJob['nFiles'] = 0
        processingJob['status'] = dmProcessingStatus.DM_PROCESSING_STATUS_PENDING
        ProcessingJobTracker.getInstance().put(jobId, processingJob)
        self.logger.debug('Starting processing job %s timer' % jobId)

        timer = threading.Timer(self.PROCESSING_JOB_START_DELAY_IN_SECONDS, self.runProcessingJob, args=[processingJob])
        timer.start()
        return processingJob

    def runProcessingJob(self, processingJob):
        try:
            childProcessEvent = threading.Event()
            processingJob.childProcessEvent = childProcessEvent
            jobId = processingJob['id']
            self.logger.debug('Timer started for processing job %s.' % jobId)

            # Resolve files
            filePathList = self.resolveFileSpec(processingJob)
            if not filePathList:
                raise InvalidRequest('There are no input files available for processing.')
            self.logger.debug('There are %s files for processing job %s.' % (len(filePathList), jobId))
            processingJob['nFiles'] = len(filePathList)
            workflowStages = processingJob.get('workflow').get('stages')
            workflowStageKeys = workflowStages.keys()
            workflowStageKeys.sort()
            processingJob['status'] = dmProcessingStatus.DM_PROCESSING_STATUS_RUNNING
            childProcessNumber = 0
            workingDir = processingJob.get('workingDir')
            for stageKey in workflowStageKeys:
                if processingJob['status'] != dmProcessingStatus.DM_PROCESSING_STATUS_RUNNING:
                    self.logger.debug('Processing job %s status is %s, exiting workflow at stage %s' % (jobId, processingJob['status'], stageKey))
                    break

                self.logger.debug('Starting stage %s for processing job %s.' % (stageKey,jobId))
                workflowStage = workflowStages.get(stageKey)
                workflowStage['childProcesses'] = {}
                workflowStage['nRunningChildProcesses'] = 0
                workflowStage['nQueuedChildProcesses'] = 0
                command = workflowStage.get('command')
                processingJob['activeStage'] = stageKey
                variableNames = [word for word in command.split() if word.startswith('$')]
                self.logger.debug('Variables found for stage %s: ' % variableNames)
                iterateOverFiles = False
                for v in variableNames:
                    variableName = v[1:] # remove '$'
                    variableValue = processingJob.get(variableName)
                    if variableName == 'filePathList':
                        variableValue = ' '.join(filePathList)
                    if variableValue is not None:
                        command = command.replace(v, variableValue)
                    if variableName == 'filePath':
                        iterateOverFiles = True

                if iterateOverFiles:
                    # We iterate over all files
                    for f in filePathList:
                        childProcessEvent.clear()
                        if processingJob['status'] != dmProcessingStatus.DM_PROCESSING_STATUS_RUNNING:
                            self.logger.debug('Processing job %s status is %s, exiting workflow at stage %s' % (jobId, processingJob['status'], stageKey))
                            break

                        # Wait until we can queue child process
                        while True:
                            nQueuedChildProcesses = workflowStage.get('nQueuedChildProcesses')
                            nRunningChildProcesses = workflowStage.get('nRunningChildProcesses')
                            nChildProcesses = nQueuedChildProcesses + nRunningChildProcesses
                            if nChildProcesses < self.MAX_NUMBER_OF_CHILD_PROCESSES:
                                break
                            else:
                                self.logger.debug('There are %s child processes for stage %s (processing job %s), cannot create new one' % (nChildProcesses, stageKey, jobId))
                            childProcessEvent.wait(self.CHILD_PROCESSES_EVENT_TIMEOUT_IN_SECONDS)


                        childCommand = command.replace('$filePath', f)
                        self.logger.debug('Execution command for stage %s, child process %s: %s' % (stageKey, childProcessNumber, childCommand))
                        childProcess = self.createChildProcess(stageKey, childProcessNumber, childCommand, workingDir)
                        self.pushToExecutionQueue(processingJob, childProcess)
                        childProcessNumber += 1

                else:
                    childCommand = command
                    self.logger.debug('Execution command for stage %s, child process %s: %s' % (stageKey, childProcessNumber, childCommand))
                    childProcess = self.createChildProcess(stageKey, childProcessNumber, childCommand, workingDir)
                    self.pushToExecutionQueue(processingJob, childProcess)
                    childProcessNumber += 1

                # Child processed queued, wait until they finish
                while True:
                    childProcessEvent.clear()
                    nQueuedChildProcesses = workflowStage.get('nQueuedChildProcesses')
                    nRunningChildProcesses = workflowStage.get('nRunningChildProcesses')
                    nChildProcesses = nQueuedChildProcesses + nRunningChildProcesses
                    if nChildProcesses == 0:
                        self.logger.debug('No more queued/running child processes for stage %s (processing job %s)' % (stageKey, jobId))
                        break
                    else:
                        self.logger.debug('There are %s queued/running child processes for stage %s (processing job %s)' % (nChildProcesses, stageKey, jobId))
                        childProcessEvent.wait(self.CHILD_PROCESSES_EVENT_TIMEOUT_IN_SECONDS)
                 
                
        except Exception, ex:
            processingJob['status'] = dmProcessingStatus.DM_PROCESSING_STATUS_FAILED
            processingJob['errorMessage'] = str(ex)
            self.logger.error('Processing job %s failed: %s' % (jobId,str(ex)))
        if processingJob['status'] == dmProcessingStatus.DM_PROCESSING_STATUS_RUNNING:
            processingJob['status'] = dmProcessingStatus.DM_PROCESSING_STATUS_DONE
            self.logger.debug('Processing job %s is done.' % jobId)
        self.logger.debug('Processing job: %s' % processingJob)

    def pushToExecutionQueue(self, processingJob, childProcess):
        self.executionQueue.push((processingJob, childProcess))
        processingJob.childProcessQueued(childProcess)
        self.setEvent()
   
    def createChildProcess(self, stageId, childProcessNumber, command, workingDir):
        childProcess = ChildProcess({
            'stageId' : stageId,
            'childProcessNumber' : childProcessNumber,
            'command' : command,
            'workingDir' : workingDir,
        })
        return childProcess

    @ThreadingUtility.synchronize
    def start(self):
        self.logger.debug('Starting execution threads')
        for i in range(0, self.nExecutionThreads):
            tName = 'ExecutionThread-%s' % i
            t = ExecutionThread(tName, self, self.executionQueue)
            t.start()
            self.executionThreadDict[tName] = t

    def stop(self):
        self.logger.debug('Stopping execution threads')
        for (tName, t) in self.executionThreadDict.items():
            t.stop()
        self.setEvent()
        for (tName, t) in self.executionThreadDict.items():
            t.join()

    @ThreadingUtility.synchronize
    def setEvent(self):
         self.eventFlag.set()

    @ThreadingUtility.synchronize
    def clearEvent(self):
        self.eventFlag.clear()

    def waitOnEvent(self, timeoutInSeconds=None):
        self.eventFlag.wait(timeoutInSeconds)

####################################################################
# Testing

if __name__ == '__main__':
    LoggingManager.getInstance().configure()
    LoggingManager.getInstance().setConsoleLogLevel('DEBUG')
    em = ExecutionManager.getInstance()
    print em
    em.start()
    # Stage Keys
    #   command (required)
    #   execOutFormat (optional, to be parsed for variables like $jobId )
    #   workingDir (optional, default .)
    #   dataDir (optional, default $workingDir)
    #   monitorCmd (optional, if exists, will execute monitoring in a timer)
    #   parallelExec (optional, default False)
    #   filePathList, filePathPattern, or fileQueryDict (one must be present)

    # If $filePathList or $filePath is in the argument list, and
    # job spec contains filePathPattern or fileQueryDict, files will be
    # resolved into filePathList
    # If $filePath is in the argument list, filePathList is iterated over
    # for a particular stage 

    # Variables that get filled automatically
    #     $username : DM username
    #     $execHost : execution host
    #     $id : job id
    #     $startTime : procesing start time
    #     $endTime : procesing end time
     
    workflow = {u'owner': u'sveseli', u'stages': {
        '1' : {u'command': u'/bin/date', 'stopOnFailure' : False}, 
        '2' : {u'command': u'/bin/ls -l $filePath', 'parallelExec' : True},
        '3' : {u'command': u'/bin/ls -c1 $filePathList'},
        '4' : {u'command': u'/bin/echo Energy is $energyArg current is $CURRENT_ARG'},
        }, u'description': u'My first workflow', u'name': u'workflow-01', u'id': u'589396e0e20bf2465e3a6bf0'}

    processingJob = ProcessingJob({ 
        'workflow' : workflow,
        'experimentName' : 'exp-01',
        'energyArg' : '2TeV', 
        'CURRENT_ARG' : '2mA',
        'filePathList' : [ 'testfile01', 'testfile02', 'testfile03' ],
        'dataDir' : '/tmp/data',
        'workingDir' : '/tmp/data',
    })
    em.startProcessingJob(processingJob)

    time.sleep(180)
    em.stop()