# coding=utf-8
"""Earthdiagnostics workflow manager"""
import time
import datetime
import operator
import sys
import threading
import traceback

# noinspection PyCompatibility
from concurrent.futures import ThreadPoolExecutor
from functools import cmp_to_key
from threading import Thread
import six

from bscearth.utils.log import Log

from earthdiagnostics.datafile import StorageStatus, LocalStatus
from earthdiagnostics.diagnostic import (
    DiagnosticStatus,
    Diagnostic,
    DiagnosticOptionError,
)
from earthdiagnostics.utils import Utils, TempFile


class WorkManager(object):
    """
    Class to produce and control the workflow of EarthDiagnostics

    Parameters
    ----------
    config: Config
    data_manager: DataManager
    """

    def __init__(self, config, data_manager):
        self.jobs = {}
        self.jobs[DiagnosticStatus.WAITING] = []
        self.jobs[DiagnosticStatus.READY] = []
        self.jobs[DiagnosticStatus.RUNNING] = []
        self.jobs[DiagnosticStatus.COMPLETED] = []
        self.jobs[DiagnosticStatus.FAILED] = []

        self.config = config
        self.time = {}
        self.had_errors = False
        self.data_manager = data_manager
        self.uploads_failed = []

    def prepare_job_list(self):
        """Create the list of jobs to run"""
        self._register_diagnostics()
        for fulldiag in self.config.get_commands():
            Log.info("Adding {0} to diagnostic list", fulldiag)
            diag_options = fulldiag.split(",")
            diag_class = Diagnostic.get_diagnostic(diag_options[0])
            if diag_class:
                try:
                    for job in diag_class.generate_jobs(self, diag_options):
                        self.add_job(job)
                        for subjob in job.subjobs:
                            self.add_job(subjob)
                except DiagnosticOptionError as ex:
                    Log.error(
                        "Can not configure diagnostic {0}: {1}",
                        diag_options[0],
                        ex,
                    )
                    self.had_errors = True
            else:
                Log.error(
                    "{0} is not an available diagnostic", diag_options[0]
                )
                self.had_errors = True

    def add_job(self, job, old_status=None):
        if old_status is not None:
            self.jobs[old_status].remove(job)
        if job not in self.jobs[job.status]:
            self.jobs[job.status].append(job)

    def run(self):
        """
        Run all the diagnostics

        Returns
        -------
        bool
            Only True if all diagnostic were correctly executed
        """
        if (
            not self.jobs[DiagnosticStatus.WAITING]
            and not self.jobs[DiagnosticStatus.READY]
        ):
            Log.result("No diagnostics to run")
            return True

        start_time = datetime.datetime.now()
        Log.info("Starting to compute at {0}", start_time)
        self.threads = Utils.available_cpu_count()
        if 0 < self.config.max_cores < self.threads:
            self.threads = self.config.max_cores
        Log.info("Using {0} threads", self.threads)

        self.downloader = Downloader()
        self.uploader = ThreadPoolExecutor(self.config.parallel_uploads)
        self.executor = ThreadPoolExecutor(self.threads)

        self.lock = threading.Lock()
        self.lock.acquire()

        for job in self.jobs[DiagnosticStatus.WAITING].copy():
            job.request_data()
            job.declare_data_generated()
            job.subscribe(self, self._job_status_changed)
            if self.config.skip_diags_done:
                if job.can_skip_run():
                    Log.info("Diagnostic {0} already done. Skipping !", job)
                    job.status = DiagnosticStatus.COMPLETED
                    continue
            job.check_is_ready()

        for file_object in self.data_manager.requested_files.values():
            file_object.subscribe(self, self._file_object_status_changed)
            if file_object.download_required():
                self.downloader.submit(file_object)

        self.downloader.start()
        printer_lock = threading.Lock()
        printer_lock.acquire()
        printer = Thread(
            target=self._print_status, name="Printer", args=(printer_lock,)
        )
        printer.start()

        self.lock.acquire()
        printer_lock.release()
        self.downloader.shutdown()
        self.executor.shutdown()
        self.uploader.shutdown(True)
        printer.join()

        TempFile.clean()
        finish_time = datetime.datetime.now()
        Log.result("Diagnostics finished at {0}", finish_time)
        Log.result("Elapsed time: {0}\n", finish_time - start_time)
        self._print_errors()
        self._print_stats()
        return not self.had_errors

    def _print_status(self, lock):
        interval = 60
        while True:
            if six.PY3:
                if lock.acquire(blocking=True, timeout=interval):
                    return
            else:
                step = 0.5
                for _ in range(int(interval / step)):
                    if lock.acquire(False):
                        return
                    time.sleep(step)

            Log.info("Current status:")
            Log.info("===============")
            Log.info(
                "Waiting:      {0:4}", len(self.jobs[DiagnosticStatus.WAITING])
            )
            Log.info(
                "Ready to run: {0:4}", len(self.jobs[DiagnosticStatus.READY])
            )
            Log.info(
                "Running:      {0:4}", len(self.jobs[DiagnosticStatus.RUNNING])
            )
            Log.info(
                "Completed:    {0:4}",
                len(self.jobs[DiagnosticStatus.COMPLETED]),
            )
            Log.info(
                "Failed:       {0:4}", len(self.jobs[DiagnosticStatus.FAILED])
            )
            Log.info("===============")

    def _job_status_changed(self, job, old_status):
        self.add_job(job, old_status)
        if job.status == DiagnosticStatus.READY:
            self.executor.submit(self._run_job, job)
        for request in job._requests:
            if request.only_suscriber(self):
                del self.data_manager.requested_files[request.remote_file]
                request.unsubscribe(self)
                request.clean_local()
        self._check_completion()

    def _file_object_status_changed(self, file_object):
        Log.debug(
            "Checking file {0}. Local status {0.local_status} "
            "Storage status{0.storage_status}",
            file_object,
        )
        if file_object.download_required():
            self.downloader.submit(file_object)
            return
        if file_object.upload_required():
            file_object.storage_status = StorageStatus.UPLOADING
            self.uploader.submit(file_object.upload)
            return
        if file_object.storage_status == StorageStatus.FAILED:
            self.uploads_failed.append(file_object)
        if (
            file_object.local_status != LocalStatus.COMPUTING
            and file_object.storage_status != StorageStatus.UPLOADING
            and file_object.only_suscriber(self)
        ):
            del self.data_manager.requested_files[file_object.remote_file]
            file_object.unsubscribe(self)
            file_object.clean_local()
        self._check_completion()

    def _check_completion(self):
        self._pause_downloader_if_required()

        if self._jobs_running_or_ready():
            return False
        if self._data_downloading_or_uploading():
            return False

        try:
            self.lock.release()
        except threading.ThreadError:
            pass
        return True

    def _jobs_running_or_ready(self):
        if (
            self.jobs[DiagnosticStatus.READY]
            or self.jobs[DiagnosticStatus.RUNNING]
        ):
            return True

        for job in self.jobs[DiagnosticStatus.WAITING]:
            if job.all_requests_in_storage():
                return True
        return False

    def _data_downloading_or_uploading(self):
        for request in self.data_manager.requested_files.values():
            if request.storage_status == StorageStatus.UPLOADING:
                return True
            if request.local_status == LocalStatus.DOWNLOADING:
                return True
            if request.upload_required():
                return True
            if request.download_required():
                return True
        return False

    def _pause_downloader_if_required(self):
        self.downloader.on_hold = len(self.jobs[DiagnosticStatus.READY]) > 20

    def _print_stats(self):
        Log.info("Time consumed by each diagnostic class")
        Log.info("--------------------------------------")

        times = {}
        for job in (
            self.jobs[DiagnosticStatus.COMPLETED]
            + self.jobs[DiagnosticStatus.FAILED]
        ):
            job_type = job.alias
            if job_type in times.keys():
                times[job_type] += job.consumed_time
            else:
                times[job_type] = job.consumed_time

        for diag in sorted(times, key=operator.itemgetter(1)):
            Log.info("{0:23} {1:}", diag, times[diag])

    def _print_errors(self):
        if self.jobs[DiagnosticStatus.FAILED]:
            self.had_errors = True
            Log.error("Failed jobs")
            Log.error("-----------")
            for job in self.jobs[DiagnosticStatus.FAILED]:
                Log.error("{0}: {0.message}", job)
            Log.error(
                "Total wasted time: {0}",
                sum(
                    [
                        job.consumed_time
                        for job in self.jobs[DiagnosticStatus.FAILED]
                    ],
                    datetime.timedelta(),
                ),
            )
            Log.info("")

        if self.uploads_failed:
            self.had_errors = True
            Log.error("Failed uploads")
            Log.error("--------------")
            for file_object in self.uploads_failed:
                Log.error("{0}", file_object.remote_file)
            Log.info("")

    @staticmethod
    def _run_job(job):
        start_time = datetime.datetime.now()
        try:
            Log.info("Starting {0}", job)
            job.status = DiagnosticStatus.RUNNING
            job.compute()
        except Exception as ex:
            job.consumed_time = datetime.datetime.now() - start_time
            exc_type, _, exc_traceback = sys.exc_info()
            job.message = "{0}\n{1}".format(
                ex, "".join(traceback.format_tb(exc_traceback))
            )
            Log.error("Job {0} failed ({2}): {1}", job, job.message, exc_type)
            job.status = DiagnosticStatus.FAILED
            return False

        job.consumed_time = datetime.datetime.now() - start_time
        Log.result("Finished {0}", job)
        job.status = DiagnosticStatus.COMPLETED
        return True

    count = 0

    @staticmethod
    def _register_diagnostics():
        WorkManager._register_ocean_diagnostics()
        WorkManager._register_general_diagnostics()
        WorkManager._register_stats_diagnostics()

    @staticmethod
    def _register_stats_diagnostics():
        from earthdiagnostics.statistics.monthlypercentile import (
            MonthlyPercentile,
        )
        from earthdiagnostics.statistics.climatologicalpercentile import (
            ClimatologicalPercentile,
        )
        from earthdiagnostics.statistics.daysoverpercentile import (
            DaysOverPercentile,
        )
        from earthdiagnostics.statistics.discretize import Discretize

        Diagnostic.register(MonthlyPercentile)
        Diagnostic.register(ClimatologicalPercentile)
        Diagnostic.register(DaysOverPercentile)
        Diagnostic.register(Discretize)

    @staticmethod
    def _register_general_diagnostics():
        from earthdiagnostics.general.attribute import Attribute
        from earthdiagnostics.general.timemean import (
            DailyMean,
            MonthlyMean,
            YearlyMean,
        )
        from earthdiagnostics.general.module import Module
        from earthdiagnostics.general.rewrite import Rewrite
        from earthdiagnostics.general.scale import Scale
        from earthdiagnostics.general.verticalmeanmetersiris import (
            VerticalMeanMetersIris,
        )
        from earthdiagnostics.general.simplify_dimensions import (
            SimplifyDimensions,
        )

        Diagnostic.register(DailyMean)
        Diagnostic.register(MonthlyMean)
        Diagnostic.register(YearlyMean)
        Diagnostic.register(Rewrite)
        Diagnostic.register(Scale)
        Diagnostic.register(Attribute)
        Diagnostic.register(Module)
        Diagnostic.register(VerticalMeanMetersIris)
        Diagnostic.register(SimplifyDimensions)

    @staticmethod
    def _register_ocean_diagnostics():
        from .ocean.mixedlayerheatcontent import MixedLayerHeatContent
        from .ocean.mixedlayersaltcontent import MixedLayerSaltContent
        from .ocean.siasiesiv import Siasiesiv
        from .ocean.verticalmean import VerticalMean
        from .ocean.verticalmeanmeters import VerticalMeanMeters
        from .ocean.verticalgradient import VerticalGradient
        from .ocean.indices import Indices
        from .ocean.interpolate import Interpolate
        from .ocean.interpolatecdo import InterpolateCDO
        from .ocean.moc import Moc
        from .ocean.areamoc import AreaMoc
        from .ocean.maxmoc import MaxMoc
        from .ocean.psi import Psi
        from .ocean.gyres import Gyres
        from .ocean.convectionsites import ConvectionSites
        from .ocean.cutsection import CutSection
        from .ocean.averagesection import AverageSection
        from .ocean.heatcontentlayer import HeatContentLayer
        from .ocean.heatcontent import HeatContent
        from .ocean.regionmean import RegionMean
        from .ocean.regionsum import RegionSum
        from .ocean.rotation import Rotation
        from .ocean.sivolume import Sivolume
        from .ocean.sivol2d import Sivol2d
        from .ocean.zonalmean import ZonalMean
        from .ocean.density import Density

        Diagnostic.register(MixedLayerSaltContent)
        Diagnostic.register(Siasiesiv)
        Diagnostic.register(VerticalMean)
        Diagnostic.register(VerticalMeanMeters)
        Diagnostic.register(Indices)
        Diagnostic.register(Interpolate)
        Diagnostic.register(InterpolateCDO)
        Diagnostic.register(Moc)
        Diagnostic.register(AreaMoc)
        Diagnostic.register(MaxMoc)
        Diagnostic.register(Psi)
        Diagnostic.register(Gyres)
        Diagnostic.register(ConvectionSites)
        Diagnostic.register(CutSection)
        Diagnostic.register(AverageSection)
        Diagnostic.register(MixedLayerHeatContent)
        Diagnostic.register(HeatContentLayer)
        Diagnostic.register(HeatContent)
        Diagnostic.register(RegionMean)
        Diagnostic.register(RegionSum)
        Diagnostic.register(Rotation)
        Diagnostic.register(VerticalGradient)
        Diagnostic.register(Sivolume)
        Diagnostic.register(Sivol2d)
        Diagnostic.register(ZonalMean)
        Diagnostic.register(Density)


class Downloader(object):
    """
    Download manager for EarthDiagnostics

    We are not using a ThreadPoolExecutor because we want to be able to
    control priorities in the download
    """

    def __init__(self):
        self._downloads = []
        self._lock = threading.Lock()
        self.stop = False
        self.on_hold = False

    def start(self):
        """Create the downloader thread and initialize it"""
        self._thread = threading.Thread(target=self._downloader)
        self._thread.start()

    def submit(self, datafile):
        """Add a datafile to the download queue"""
        self._lock.acquire()
        self._downloads.append(datafile)
        self._lock.release()

    def _downloader(self):
        try:
            while True:
                with self._lock:
                    if not self._downloads or self.on_hold:
                        if self.stop:
                            return
                        time.sleep(0.1)
                        continue
                    self._downloads.sort(
                        key=cmp_to_key(Downloader._prioritize)
                    )
                    datafile = self._downloads[0]
                    self._downloads.remove(datafile)
                datafile.download()
        except Exception as ex:
            Log.critical(
                "Unhandled error at downloader: {0}\n{1}",
                ex,
                traceback.print_exc(),
            )

    @staticmethod
    def _suscribers_waiting(datafile):
        waiting = 0
        for diag in datafile.suscribers:
            if not isinstance(diag, Diagnostic):
                continue
            if diag.pending_requests() == 1:
                waiting += 1
        return waiting

    @staticmethod
    def _prioritize(datafile1, datafile2):
        waiting = Downloader._suscribers_waiting(
            datafile1
        ) - Downloader._suscribers_waiting(datafile2)
        if waiting:
            return -waiting

        suscribers2 = len(datafile2.suscribers)
        if datafile1.suscribers is None:
            suscribers1 = 0
        else:
            suscribers1 = len(datafile1.suscribers)

        if datafile2.suscribers is None:
            suscribers2 = 0
        else:
            suscribers2 = len(datafile2.suscribers)

        suscribers = suscribers1 - suscribers2
        if suscribers:
            return -suscribers
        return 0

    def shutdown(self):
        """Stop the downloader after all downloads have finished"""
        self.stop = True
        self._thread.join()