import datetime

from cloudbot.util import formatting


def timesince(d, now=None, count=2, accuracy=6, simple=False):
    """
    Takes two datetime objects and returns the time between d and now
    as a nicely formatted string, e.g. "10 minutes". If d occurs after now,
    then "0 minutes" is returned.
    This function has a number of optional arguments that can be combined:

    SIMPLE: displays the time in a simple format
    >> timesince(SECONDS)
    1 hour, 2 minutes and 34 seconds
    >> timesince(SECONDS, simple=True)
    1h 2m 34s

    COUNT: how many periods should be shown (default 3)
    >> timesince(SECONDS)
    147 years, 9 months and 8 weeks
    >> timesince(SECONDS, count=6)
    147 years, 9 months, 7 weeks, 18 hours, 12 minutes and 34 seconds
    """

    # Convert int or float (unix epoch) to datetime.datetime for comparison
    if isinstance(d, int) or isinstance(d, float):
        d = datetime.datetime.fromtimestamp(d)

    if isinstance(now, int) or isinstance(now, float):
        now = datetime.datetime.fromtimestamp(now)

    # Convert datetime.date to datetime.datetime for comparison.
    if not isinstance(d, datetime.datetime):
        d = datetime.datetime(d.year, d.month, d.day)
    if now and not isinstance(now, datetime.datetime):
        now = datetime.datetime(now.year, now.month, now.day)

    if not now:
        now = datetime.datetime.now()

    # ignore microsecond part of 'd' since we removed it from 'now'
    delta = now - (d - datetime.timedelta(0, 0, d.microsecond))
    since = delta.days * 24 * 60 * 60 + delta.seconds

    if since <= 0:
        # d is in the future compared to now, stop processing.
        return '0 ' + 'minutes'

    # pass the number in seconds on to format_time to make the output string
    return format_time(since, count, accuracy, simple)


def timeuntil(d, now=None, count=2, accuracy=6, simple=False):
    """
    Like timesince, but returns a string measuring the time until
    the given time.
    """
    if not now:
        now = datetime.datetime.now()
    return timesince(now, d, count, accuracy, simple)


def format_time(seconds, count=3, accuracy=6, simple=False):
    """
    Takes a length of time in seconds and returns a string describing that length of time.
    This function has a number of optional arguments that can be combined:

    SIMPLE: displays the time in a simple format
    >> format_time(SECONDS)
    1 hour, 2 minutes and 34 seconds
    >> format_time(SECONDS, simple=True)
    1h 2m 34s

    COUNT: how many periods should be shown (default 3)
    >> format_time(SECONDS)
    147 years, 9 months and 8 weeks
    >> format_time(SECONDS, count=6)
    147 years, 9 months, 7 weeks, 18 hours, 12 minutes and 34 seconds
    """

    if simple:
        periods = [
            ('c', 60 * 60 * 24 * 365 * 100),
            ('de', 60 * 60 * 24 * 365 * 10),
            ('y', 60 * 60 * 24 * 365),
            ('m', 60 * 60 * 24 * 30),
            ('d', 60 * 60 * 24),
            ('h', 60 * 60),
            ('m', 60),
            ('s', 1)
        ]
    else:
        periods = [
            (('century', 'centuries'), 60 * 60 * 24 * 365 * 100),
            (('decade', 'decades'), 60 * 60 * 24 * 365 * 10),
            (('year', 'years'), 60 * 60 * 24 * 365),
            (('month', 'months'), 60 * 60 * 24 * 30),
            (('day', 'days'), 60 * 60 * 24),
            (('hour', 'hours'), 60 * 60),
            (('minute', 'minutes'), 60),
            (('second', 'seconds'), 1)
        ]

    periods = periods[-accuracy:]

    strings = []
    i = 0
    for period_name, period_seconds in periods:
        print(i, period_name)
        if i < count:
            if seconds > period_seconds:
                period_value, seconds = divmod(seconds, period_seconds)
                i += 1
                if simple:
                    strings.append("{}{}".format(period_value, period_name))
                else:
                    if period_value == 1:
                        strings.append("{} {}".format(period_value, period_name[0]))
                    else:
                        strings.append("{} {}".format(period_value, period_name[1]))
        else:
            break

    if simple:
        return " ".join(strings)
    else:
        return formatting.get_text_list(strings, "and")