# Author: Nic Wolfe <nic@wolfeden.ca>
# URL: http://code.google.com/p/sickbeard/
#
# This file is part of SickGear.
#
# SickGear 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 3 of the License, or
# (at your option) any later version.
#
# SickGear 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 SickGear.  If not, see <http://www.gnu.org/licenses/>.

from lib.six import iteritems

from lib.dateutil import tz, zoneinfo
from lib.tzlocal import get_localzone
from sickbeard import db
from sickbeard import helpers
from sickbeard import logger
from sickbeard import encodingKludge as ek
from os.path import basename, join, isfile
from itertools import chain
import os
import re
import datetime
import sickbeard

# regex to parse time (12/24 hour format)
time_regex = re.compile(r'(\d{1,2})(([:.](\d{2}))? ?([PA][. ]? ?M)|[:.](\d{2}))\b', flags=re.I)
am_regex = re.compile(r'(A[. ]? ?M)', flags=re.I)
pm_regex = re.compile(r'(P[. ]? ?M)', flags=re.I)

network_dict = None
network_dupes = None
last_failure = {'datetime': datetime.datetime.fromordinal(1), 'count': 0}
max_retry_time = 900
max_retry_count = 3

country_timezones = {
    'AU': 'Australia/Sydney', 'AR': 'America/Buenos_Aires', 'AUSTRALIA': 'Australia/Sydney', 'BR': 'America/Sao_Paulo',
    'CA': 'Canada/Eastern', 'CZ': 'Europe/Prague', 'DE': 'Europe/Berlin', 'ES': 'Europe/Madrid',
    'FI': 'Europe/Helsinki', 'FR': 'Europe/Paris', 'HK': 'Asia/Hong_Kong', 'IE': 'Europe/Dublin',
    'IS': 'Atlantic/Reykjavik', 'IT': 'Europe/Rome', 'JP': 'Asia/Tokyo', 'MX': 'America/Mexico_City',
    'MY': 'Asia/Kuala_Lumpur', 'NL': 'Europe/Amsterdam', 'NZ': 'Pacific/Auckland', 'PH': 'Asia/Manila',
    'PT': 'Europe/Lisbon', 'RU': 'Europe/Kaliningrad', 'SE': 'Europe/Stockholm', 'SG': 'Asia/Singapore',
    'TW': 'Asia/Taipei', 'UK': 'Europe/London', 'US': 'US/Eastern', 'ZA': 'Africa/Johannesburg'}


def reset_last_retry():
    global last_failure
    last_failure = {'datetime': datetime.datetime.fromordinal(1), 'count': 0}


def update_last_retry():
    global last_failure
    last_failure = {'datetime': datetime.datetime.now(), 'count': last_failure.get('count', 0) + 1}


def should_try_loading():
    global last_failure
    if last_failure.get('count', 0) >= max_retry_count and \
            (datetime.datetime.now() - last_failure.get('datetime', datetime.datetime.fromordinal(1))).seconds < max_retry_time:
        return False
    return True


def tz_fallback(t):
    return t if isinstance(t, datetime.tzinfo) else tz.tzlocal()


def get_tz():
    t = get_localzone()
    if isinstance(t, datetime.tzinfo) and hasattr(t, 'zone') and t.zone and hasattr(sickbeard, 'ZONEINFO_DIR'):
        try:
            t = tz_fallback(tz.gettz(t.zone, zoneinfo_priority=True))
        except:
            t = tz_fallback(t)
    else:
        t = tz_fallback(t)
    return t

sb_timezone = get_tz()


# helper to remove failed temp download
def _remove_zoneinfo_failed(filename):
    try:
        ek.ek(os.remove, filename)
    except:
        pass


# helper to remove old unneeded zoneinfo files
def _remove_old_zoneinfo():
    zonefilename = zoneinfo.ZONEFILENAME
    if None is zonefilename:
        return
    cur_zoneinfo = ek.ek(basename, zonefilename)

    cur_file = helpers.real_path(ek.ek(join, sickbeard.ZONEINFO_DIR, cur_zoneinfo))

    for (path, dirs, files) in chain.from_iterable(ek.ek(os.walk,
                                     helpers.real_path(di)) for di in (sickbeard.ZONEINFO_DIR, ek.ek(os.path.dirname, zoneinfo.__file__))):
        for filename in files:
            if filename.endswith('.tar.gz'):
                file_w_path = ek.ek(join, path, filename)
                if file_w_path != cur_file and ek.ek(isfile, file_w_path):
                    try:
                        ek.ek(os.remove, file_w_path)
                        logger.log(u'Delete unneeded old zoneinfo File: %s' % file_w_path)
                    except:
                        logger.log(u'Unable to delete: %s' % file_w_path, logger.ERROR)


# update the dateutil zoneinfo
def _update_zoneinfo():
    if not should_try_loading():
        return

    global sb_timezone
    sb_timezone = get_tz()

    # now check if the zoneinfo needs update
    url_zv = 'https://raw.githubusercontent.com/Prinz23/sb_network_timezones/master/zoneinfo.txt'

    url_data = helpers.getURL(url_zv)
    if url_data is None:
        update_last_retry()
        # When urlData is None, trouble connecting to github
        logger.log(u'Loading zoneinfo.txt failed, this can happen from time to time. Unable to get URL: %s' % url_zv,
                   logger.WARNING)
        return
    else:
        reset_last_retry()

    zonefilename = zoneinfo.ZONEFILENAME
    cur_zoneinfo = zonefilename
    if None is not cur_zoneinfo:
        cur_zoneinfo = ek.ek(basename, zonefilename)
    zonefile = helpers.real_path(ek.ek(join, sickbeard.ZONEINFO_DIR, cur_zoneinfo))
    zonemetadata = zoneinfo.gettz_db_metadata() if ek.ek(os.path.isfile, zonefile) else None
    (new_zoneinfo, zoneinfo_md5) = url_data.decode('utf-8').strip().rsplit(u' ')
    newtz_regex = re.search(r'(\d{4}[^.]+)', new_zoneinfo)
    if not newtz_regex or len(newtz_regex.groups()) != 1:
        return
    newtzversion = newtz_regex.group(1)

    if cur_zoneinfo is not None and zonemetadata is not None and 'tzversion' in zonemetadata and zonemetadata['tzversion'] == newtzversion:
        return

    # now load the new zoneinfo
    url_tar = u'https://raw.githubusercontent.com/Prinz23/sb_network_timezones/master/%s' % new_zoneinfo

    zonefile_tmp = re.sub(r'\.tar\.gz$', '.tmp', zonefile)

    if ek.ek(os.path.exists, zonefile_tmp):
        try:
            ek.ek(os.remove, zonefile_tmp)
        except:
            logger.log(u'Unable to delete: %s' % zonefile_tmp, logger.ERROR)
            return

    if not helpers.download_file(url_tar, zonefile_tmp):
        return

    if not ek.ek(os.path.exists, zonefile_tmp):
        logger.log(u'Download of %s failed.' % zonefile_tmp, logger.ERROR)
        return

    new_hash = str(helpers.md5_for_file(zonefile_tmp))

    if zoneinfo_md5.upper() == new_hash.upper():
        logger.log(u'Updating timezone info with new one: %s' % new_zoneinfo, logger.MESSAGE)
        try:
            # remove the old zoneinfo file
            if cur_zoneinfo is not None:
                old_file = helpers.real_path(
                    ek.ek(join, sickbeard.ZONEINFO_DIR, cur_zoneinfo))
                if ek.ek(os.path.exists, old_file):
                    ek.ek(os.remove, old_file)
            # rename downloaded file
            ek.ek(os.rename, zonefile_tmp, zonefile)
            from dateutil.zoneinfo import gettz
            if '_CLASS_ZONE_INSTANCE' in gettz.func_globals:
                gettz.func_globals.__setitem__('_CLASS_ZONE_INSTANCE', list())

            sb_timezone = get_tz()
        except:
            _remove_zoneinfo_failed(zonefile_tmp)
            return
    else:
        _remove_zoneinfo_failed(zonefile_tmp)
        logger.log(u'MD5 hash does not match: %s File: %s' % (zoneinfo_md5.upper(), new_hash.upper()), logger.ERROR)
        return


# update the network timezone table
def update_network_dict():
    if not should_try_loading():
        return

    _remove_old_zoneinfo()
    _update_zoneinfo()
    load_network_conversions()

    d = {}

    # network timezones are stored on github pages
    url = 'https://raw.githubusercontent.com/Prinz23/sb_network_timezones/master/network_timezones.txt'

    url_data = helpers.getURL(url)
    if url_data is None:
        update_last_retry()
        # When urlData is None, trouble connecting to github
        logger.log(u'Updating network timezones failed, this can happen from time to time. URL: %s' % url, logger.WARNING)
        load_network_dict(load=False)
        return
    else:
        reset_last_retry()

    try:
        for line in url_data.splitlines():
            (key, val) = line.decode('utf-8').strip().rsplit(u':', 1)
            if key is None or val is None:
                continue
            d[key] = val
    except (IOError, OSError):
        pass

    my_db = db.DBConnection('cache.db')

    # load current network timezones
    old_d = dict(my_db.select('SELECT * FROM network_timezones'))

    # list of sql commands to update the network_timezones table
    cl = []
    for cur_d, cur_t in iteritems(d):
        h_k = cur_d in old_d
        if h_k and cur_t != old_d[cur_d]:
            # update old record
            cl.append(
                ['UPDATE network_timezones SET network_name=?, timezone=? WHERE network_name=?', [cur_d, cur_t, cur_d]])
        elif not h_k:
            # add new record
            cl.append(['INSERT INTO network_timezones (network_name, timezone) VALUES (?,?)', [cur_d, cur_t]])
        if h_k:
            del old_d[cur_d]

    # remove deleted records
    if len(old_d) > 0:
        old_items = list(va for va in old_d)
        cl.append(['DELETE FROM network_timezones WHERE network_name IN (%s)' % ','.join(['?'] * len(old_items)), old_items])

    # change all network timezone infos at once (much faster)
    if len(cl) > 0:
        my_db.mass_action(cl)
        load_network_dict()


# load network timezones from db into dict
def load_network_dict(load=True):
    global network_dict, network_dupes

    my_db = db.DBConnection('cache.db')
    sql_name = 'REPLACE(LOWER(network_name), " ", "")'
    try:
        sql = 'SELECT %s AS network_name, timezone FROM [network_timezones] ' % sql_name + \
              'GROUP BY %s HAVING COUNT(*) = 1 ORDER BY %s;' % (sql_name, sql_name)
        cur_network_list = my_db.select(sql)
        if load and (cur_network_list is None or len(cur_network_list) < 1):
            update_network_dict()
            cur_network_list = my_db.select(sql)
        network_dict = dict(cur_network_list)
    except:
        network_dict = {}

    try:

        case_dupes = my_db.select('SELECT * FROM [network_timezones] WHERE %s IN ' % sql_name +
                                  '(SELECT %s FROM [network_timezones]' % sql_name +
                                  ' GROUP BY %s HAVING COUNT(*) > 1)' % sql_name +
                                  ' ORDER BY %s;' % sql_name)
        network_dupes = dict(case_dupes)
    except:
        network_dupes = {}


# get timezone of a network or return default timezone
def get_network_timezone(network):
    if network is None:
        return sb_timezone

    timezone = None

    try:
        if zoneinfo.ZONEFILENAME is not None:
            if not network_dict:
                load_network_dict()
            try:
                timezone = tz.gettz(network_dupes.get(network) or network_dict.get(network.replace(' ', '').lower()),
                                    zoneinfo_priority=True)
            except:
                pass

            if timezone is None:
                cc = re.search(r'\(([a-z]+)\)$', network, flags=re.I)
                try:
                    timezone = tz.gettz(country_timezones.get(cc.group(1).upper()), zoneinfo_priority=True)
                except:
                    pass
    except:
        pass

    return timezone if isinstance(timezone, datetime.tzinfo) else sb_timezone


def parse_time(t):
    mo = time_regex.search(t)
    if mo is not None and len(mo.groups()) >= 5:
        if mo.group(5) is not None:
            try:
                hr = helpers.tryInt(mo.group(1))
                m = helpers.tryInt(mo.group(4))
                ap = mo.group(5)
                # convert am/pm to 24 hour clock
                if ap is not None:
                    if pm_regex.search(ap) is not None and hr != 12:
                        hr += 12
                    elif am_regex.search(ap) is not None and hr == 12:
                        hr -= 12
            except:
                hr = 0
                m = 0
        else:
            try:
                hr = helpers.tryInt(mo.group(1))
                m = helpers.tryInt(mo.group(6))
            except:
                hr = 0
                m = 0
    else:
        hr = 0
        m = 0
    if hr < 0 or hr > 23 or m < 0 or m > 59:
        hr = 0
        m = 0

    return hr, m


# parse date and time string into local time
def parse_date_time(d, t, network):

    if isinstance(t, tuple) and len(t) == 2 and isinstance(t[0], int) and isinstance(t[1], int):
        (hr, m) = t
    else:
        (hr, m) = parse_time(t)

    te = datetime.datetime.fromordinal(helpers.tryInt(d))
    try:
        if isinstance(network, datetime.tzinfo):
            foreign_timezone = network
        else:
            foreign_timezone = get_network_timezone(network)
        foreign_naive = datetime.datetime(te.year, te.month, te.day, hr, m, tzinfo=foreign_timezone)
        return foreign_naive
    except:
        return datetime.datetime(te.year, te.month, te.day, hr, m, tzinfo=sb_timezone)


def test_timeformat(t):
    mo = time_regex.search(t)
    if mo is None or len(mo.groups()) < 2:
        return False
    else:
        return True


def standardize_network(network, country):
    my_db = db.DBConnection('cache.db')
    sql_results = my_db.select('SELECT * FROM network_conversions WHERE tvrage_network = ? and tvrage_country = ?',
                               [network, country])
    if len(sql_results) == 1:
        return sql_results[0]['tvdb_network']
    else:
        return network


def load_network_conversions():

    if not should_try_loading():
        return

    conversions = []

    # network conversions are stored on github pages
    url = 'https://raw.githubusercontent.com/prinz23/sg_network_conversions/master/conversions.txt'

    url_data = helpers.getURL(url)
    if url_data is None:
        update_last_retry()
        # When urlData is None, trouble connecting to github
        logger.log(u'Updating network conversions failed, this can happen from time to time. URL: %s' % url, logger.WARNING)
        return
    else:
        reset_last_retry()

    try:
        for line in url_data.splitlines():
            (tvdb_network, tvrage_network, tvrage_country) = line.decode('utf-8').strip().rsplit(u'::', 2)
            if not (tvdb_network and tvrage_network and tvrage_country):
                continue
            conversions.append({'tvdb_network': tvdb_network, 'tvrage_network': tvrage_network, 'tvrage_country': tvrage_country})
    except (IOError, OSError):
        pass

    my_db = db.DBConnection('cache.db')

    old_d = my_db.select('SELECT * FROM network_conversions')
    old_d = helpers.build_dict(old_d, 'tvdb_network')

    # list of sql commands to update the network_conversions table
    cl = []

    for n_w in conversions:
        cl.append(['INSERT OR REPLACE INTO network_conversions (tvdb_network, tvrage_network, tvrage_country)'
                   'VALUES (?,?,?)', [n_w['tvdb_network'], n_w['tvrage_network'], n_w['tvrage_country']]])
        try:
            del old_d[n_w['tvdb_network']]
        except:
            pass

    # remove deleted records
    if len(old_d) > 0:
        old_items = list(va for va in old_d)
        cl.append(['DELETE FROM network_conversions WHERE tvdb_network'
                   ' IN (%s)' % ','.join(['?'] * len(old_items)), old_items])

    # change all network conversion info at once (much faster)
    if len(cl) > 0:
        my_db.mass_action(cl)