#!/usr/bin/env python

# pywws - Python software for USB Wireless Weather Stations
# http://github.com/jim-easterbrook/pywws
# Copyright (C) 2008-14  Jim Easterbrook  jim@jim-easterbrook.me.uk

# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program 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 General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

"""Routines to perform common tasks such as plotting gaphs or uploading files."""

from __future__ import absolute_import

from collections import deque
from datetime import datetime, timedelta
import logging
import os
import shutil
import threading

from .calib import Calib
from . import Plot
from . import Template
from .TimeZone import STDOFFSET, Local
from .toservice import ToService
from . import Upload
from . import WindRose
from . import YoWindow

class RegularTasks(object):
    def __init__(self, params, status,
                 raw_data, calib_data, hourly_data, daily_data, monthly_data,
                 asynch=False):
        self.logger = logging.getLogger('pywws.Tasks.RegularTasks')
        self.params = params
        self.status = status
        self.raw_data = raw_data
        self.calib_data = calib_data
        self.hourly_data = hourly_data
        self.daily_data = daily_data
        self.monthly_data = monthly_data
        self.asynch = asynch
        self.flush = eval(self.params.get('config', 'frequent writes', 'False'))
        # get directories
        self.work_dir = self.params.get('paths', 'work', '/tmp/weather')
        self.template_dir = self.params.get(
            'paths', 'templates', os.path.expanduser('~/weather/templates/'))
        self.graph_template_dir = self.params.get(
            'paths', 'graph_templates', os.path.expanduser('~/weather/graph_templates/'))
        self.local_dir = self.params.get(
            'paths', 'local_files', os.path.expanduser('~/weather/results/'))
        # create calibration object
        self.calibrator = Calib(self.params, self.raw_data)
        # create templater object
        self.templater = Template.Template(
            self.params, self.status, self.calib_data, self.hourly_data,
            self.daily_data, self.monthly_data)
        # create plotter objects
        self.plotter = Plot.GraphPlotter(
            self.params, self.status, self.calib_data, self.hourly_data,
            self.daily_data, self.monthly_data, self.work_dir)
        self.roseplotter = WindRose.RosePlotter(
            self.params, self.status, self.calib_data, self.hourly_data,
            self.daily_data, self.monthly_data, self.work_dir)
        # create FTP uploader object
        self.uploader = Upload.Upload(self.params)
        self.uploads_directory = os.path.join(self.work_dir, 'uploads')
        if not os.path.isdir(self.uploads_directory):
            os.makedirs(self.uploads_directory)
        # delay creation of a Twitter object until we know it's needed
        self.twitter = None
        # create a YoWindow object
        self.yowindow = YoWindow.YoWindow(self.calib_data)
        # get daytime end hour, in UTC
        self.day_end_hour = eval(params.get('config', 'day end hour', '21'))
        self.day_end_hour = (self.day_end_hour - (STDOFFSET.seconds // 3600)) % 24
        # parse "cron" sections
        self.cron = {}
        for section in self.params._config.sections():
            if section.split()[0] != 'cron':
                continue
            import croniter
            self.cron[section] = croniter.croniter(
                self.params.get(section, 'format', ''))
            self.cron[section].get_prev()
            last_update = self.status.get_datetime('last update', section)
            if last_update:
                last_update = last_update + Local.utcoffset(last_update)
                while self.cron[section].get_current(datetime) <= last_update:
                    self.cron[section].get_next()
        # create service uploader objects
        self.services = {}
        for section in self.cron.keys() + [
                       'live', 'logged', 'hourly', '12 hourly', 'daily']:
            for name in eval(self.params.get(section, 'services', '[]')):
                if name not in self.services:
                    self.services[name] = ToService(
                        self.params, self.status, self.calib_data,
                        service_name=name)
            # check for deprecated syntax
            if self.params.get(section, 'twitter') not in (None, '[]'):
                self.logger.warning(
                    'Deprecated twitter entry in [%s]', section)
            if self.params.get(section, 'yowindow'):
                self.logger.warning(
                    'Deprecated yowindow entry in [%s]', section)
        # create queues for things to upload / send
        self.tweet_queue = deque()
        self.service_queue = {}
        for name in self.services:
            self.service_queue[name] = deque()
        self.uploads_queue = deque()
        # start asynchronous thread to do uploads
        if self.asynch:
            self.logger.info('Starting asynchronous thread')
            self.shutdown_thread = threading.Event()
            self.wake_thread = threading.Event()
            self.thread = threading.Thread(target=self._asynch_thread)
            self.thread.start()

    def stop_thread(self):
        if not self.asynch:
            return
        self.shutdown_thread.set()
        self.wake_thread.set()
        self.thread.join()
        self.logger.debug('Asynchronous thread terminated')

    def _asynch_thread(self):
        try:
            while not self.shutdown_thread.isSet():
                timeout = 600
                while True:
                    self.wake_thread.wait(timeout)
                    if not self.wake_thread.isSet():
                        # main thread has stopped putting things on the queue
                        break
                    self.wake_thread.clear()
                    timeout = 2
                self.logger.debug('Doing asynchronous tasks')
                self._do_queued_tasks()
        except Exception, ex:
            self.logger.exception(ex)

    def _do_queued_tasks(self):
        while self.tweet_queue:
            tweet = self.tweet_queue[0]
            self.logger.info("Tweeting")
            if not self.twitter.Upload(tweet):
                break
            self.tweet_queue.popleft()
        for name in self.service_queue:
            service = self.services[name]
            count = 0
            while self.service_queue[name]:
                timestamp, prepared_data = self.service_queue[name][0]
                if len(self.service_queue[name]) > 1 and service.catchup <= 0:
                    # don't send queued 'catchup' records
                    pass
                elif service.send_data(timestamp, prepared_data):
                    count += 1
                else:
                    break
                self.service_queue[name].popleft()
            if count > 0:
                service.logger.info('%d records sent', count)
        while self.uploads_queue:
            file = self.uploads_queue.popleft()
            targ = os.path.join(self.uploads_directory, os.path.basename(file))
            if os.path.exists(targ):
                os.unlink(targ)
            shutil.move(file, self.uploads_directory)
        self._do_uploads()

    def has_live_tasks(self):
        if self.cron:
            return True
        yowindow_file = self.params.get('live', 'yowindow')
        if yowindow_file:
            return True
        if self.params.get('live', 'twitter') not in (None, '[]'):
            return True
        for name in eval(self.params.get('live', 'services', '[]')):
            return True
        for template in eval(self.params.get('live', 'plot', '[]')):
            return True
        for template in eval(self.params.get('live', 'text', '[]')):
            return True
        return False

    def _parse_templates(self, section, option):
        for template in eval(self.params.get(section, option, '[]')):
            if isinstance(template, (list, tuple)):
                yield template
            else:
                yield template, ''

    def _do_common(self, sections, live_data=None):
        if self.asynch and not self.thread.isAlive():
            raise RuntimeError('Asynchronous thread terminated unexpectedly')
        for section in sections:
            yowindow_file = self.params.get(section, 'yowindow')
            if yowindow_file:
                self.yowindow.write_file(yowindow_file)
                break
        for section in sections:
            templates = self.params.get(section, 'twitter')
            if templates not in (None, '[]'):
                for template in eval(templates):
                    self.do_twitter(template)
        uploads = []
        local_files = []
        service_done = []
        for section in sections:
            for name in eval(self.params.get(section, 'services', '[]')):
                if name not in service_done:
                    self._do_service(name, live_data)
                    service_done.append(name)
            for template, flags in self._parse_templates(section, 'text'):
                if 'T' in flags:
                    self.do_twitter(template, live_data)
                    continue
                upload = self.do_template(template, live_data)
                if 'L' in flags:
                    if upload not in local_files:
                        local_files.append(upload)
                elif upload not in uploads:
                    uploads.append(upload)
            for template, flags in self._parse_templates(section, 'plot'):
                upload = self.do_plot(template)
                if not upload:
                    continue
                if 'L' in flags:
                    if upload not in local_files:
                        local_files.append(upload)
                elif upload not in uploads:
                    uploads.append(upload)
        if local_files:
            if not os.path.isdir(self.local_dir):
                os.makedirs(self.local_dir)
            for file in local_files:
                targ = os.path.join(
                    self.local_dir, os.path.basename(file))
                if os.path.exists(targ):
                    os.unlink(targ)
                shutil.move(file, self.local_dir)
        for file in uploads:
            self.uploads_queue.append(file)
        if self.asynch:
            self.wake_thread.set()
        else:
            self._do_queued_tasks()

    def _do_cron(self, live_data=None):
        if not self.cron:
            return
        # get timestamp of latest data
        if live_data:
            now = live_data['idx']
        else:
            now = self.calib_data.before(datetime.max)
        if not now:
            now = datetime.utcnow()
        # convert to local time
        local_now = now + Local.utcoffset(now)
        # get list of due sections
        sections = []
        for section in self.cron:
            if self.cron[section].get_current(datetime) > local_now:
                continue
            sections.append(section)
            while self.cron[section].get_current(datetime) <= local_now:
                self.cron[section].get_next()
        if not sections:
            return
        # do it!
        self._do_common(sections, live_data)
        for section in sections:
            self.status.set('last update', section, now.isoformat(' '))

    def do_live(self, data):
        calib_data = self.calibrator.calib(data)
        self._do_common(['live'], calib_data)
        self._do_cron(calib_data)

    def do_tasks(self):
        sections = ['logged']
        self.params.unset('logged', 'last update')
        now = self.calib_data.before(datetime.max)
        if now:
            now += timedelta(minutes=self.calib_data[now]['delay'])
        else:
            now = datetime.utcnow().replace(microsecond=0)
        threshold = (now + STDOFFSET).replace(minute=0, second=0) - STDOFFSET
        last_update = self.params.get_datetime('hourly', 'last update')
        if last_update:
            self.params.unset('hourly', 'last update')
            self.status.set('last update', 'hourly', last_update.isoformat(' '))
        last_update = self.status.get_datetime('last update', 'hourly')
        if (not last_update) or (last_update < threshold):
            # time to do hourly tasks
            sections.append('hourly')
            # set 12 hourly threshold
            threshold -= timedelta(hours=(threshold.hour - self.day_end_hour) % 12)
            last_update = self.params.get_datetime('12 hourly', 'last update')
            if last_update:
                self.params.unset('12 hourly', 'last update')
                self.status.set('last update', '12 hourly', last_update.isoformat(' '))
            last_update = self.status.get_datetime('last update', '12 hourly')
            if (not last_update) or (last_update < threshold):
                # time to do 12 hourly tasks
                sections.append('12 hourly')
            # set daily threshold
            threshold -= timedelta(hours=(threshold.hour - self.day_end_hour) % 24)
            last_update = self.params.get_datetime('daily', 'last update')
            if last_update:
                self.params.unset('daily', 'last update')
                self.status.set('last update', 'daily', last_update.isoformat(' '))
            last_update = self.status.get_datetime('last update', 'daily')
            if (not last_update) or (last_update < threshold):
                # time to do daily tasks
                sections.append('daily')
        self._do_common(sections)
        for section in sections:
            self.status.set('last update', section, now.isoformat(' '))
        self._do_cron()
        if self.flush or 'hourly' in sections:
            # save any unsaved data
            self.params.flush()
            self.status.flush()
            self.raw_data.flush()
            self.calib_data.flush()
            self.hourly_data.flush()
            self.daily_data.flush()
            self.monthly_data.flush()

    def _do_uploads(self):
        # get list of pending uploads
        uploads = []
        for name in os.listdir(self.uploads_directory):
            path = os.path.join(self.uploads_directory, name)
            if os.path.isfile(path):
                uploads.append(path)
        if not uploads:
            return True
        # upload files
        if not self.uploader.connect():
            return
        for path in uploads:
            if self.uploader.upload_file(path):
                os.unlink(path)
        self.uploader.disconnect()

    def _do_service(self, name, live_data):
        service = self.services[name]
        if len(self.service_queue[name]) >= 50:
            return
        for data in service.next_data(True, live_data):
            prepared_data = service.prepare_data(data)
            if not prepared_data:
                continue
            self.service_queue[name].append((data['idx'], prepared_data))
            if len(self.service_queue[name]) >= 50:
                break
        if self.asynch:
            self.wake_thread.set()

    def do_twitter(self, template, data=None):
        if not self.twitter:
            from . import ToTwitter
            self.twitter = ToTwitter.ToTwitter(self.params)
        self.logger.info("Templating %s", template)
        input_file = os.path.join(self.template_dir, template)
        tweet = self.templater.make_text(input_file, live_data=data)[:140]
        self.tweet_queue.append(tweet)
        if self.asynch:
            self.wake_thread.set()

    def do_plot(self, template):
        self.logger.info("Graphing %s", template)
        input_file = os.path.join(self.graph_template_dir, template)
        output_file = os.path.join(self.work_dir, os.path.splitext(template)[0])
        input_xml = Plot.GraphFileReader(input_file)
        if (input_xml.get_children(self.plotter.plot_name) and
                        self.plotter.DoPlot(input_xml, output_file) == 0):
            return output_file
        if (input_xml.get_children(self.roseplotter.plot_name) and
                        self.roseplotter.DoPlot(input_xml, output_file) == 0):
            return output_file
        self.logger.warning('nothing to graph in %s', input_file)
        return None

    def do_template(self, template, data=None):
        self.logger.info("Templating %s", template)
        input_file = os.path.join(self.template_dir, template)
        output_file = os.path.join(self.work_dir, template)
        self.templater.make_file(input_file, output_file, live_data=data)
        return output_file
