# -*- coding: utf-8 -*-

import time
import datetime


def iso_2_utc(iso_ts):
    if not iso_ts or iso_ts is None:
        return 0
    delim = -1
    if not iso_ts.endswith('Z'):
        delim = iso_ts.rfind('+')
        if delim == -1:
            delim = iso_ts.rfind('-')
    if delim > -1:
        ts = iso_ts[:delim]
        sign = iso_ts[delim]
        tz = iso_ts[delim + 1:]
    else:
        ts = iso_ts
        tz = None
    if ts.find('.') > -1:
        ts = ts[:ts.find('.')]
    try:
        d = datetime.datetime.strptime(ts, '%Y-%m-%dT%H:%M:%S')
    except TypeError:
        d = datetime.datetime(*(time.strptime(ts, '%Y-%m-%dT%H:%M:%S')[0:6]))
    dif = datetime.timedelta()
    if tz:
        hours, minutes = tz.split(':')
        hours = int(hours)
        minutes = int(minutes)
        if sign == '-':
            hours = -hours
            minutes = -minutes
        dif = datetime.timedelta(minutes=minutes, hours=hours)
    utc_dt = d - dif
    epoch = datetime.datetime.utcfromtimestamp(0)
    delta = utc_dt - epoch
    try:
        seconds = delta.total_seconds()  # works only on 2.7
    except:
        seconds = delta.seconds + delta.days * 24 * 3600  # close enough
    return seconds


def uk_datetime():
    dt = datetime.datetime.utcnow() + datetime.timedelta(hours=0)
    d = datetime.datetime(dt.year, 4, 1)
    dston = d - datetime.timedelta(days=d.weekday() + 1)
    d = datetime.datetime(dt.year, 11, 1)
    dstoff = d - datetime.timedelta(days=d.weekday() + 1)
    if dston <=  dt < dstoff:
        return dt + datetime.timedelta(hours=1)
    else:
        return dt