import re
import datetime

class Snapshot(object):
    def __init__(self, snapshot_string):
        self.snapshot_string = snapshot_string
        self.re_split_tabs = re.compile(r'\t+')
        self.re_name = re.compile(r"[^/]+$")
        self.re_zvol = re.compile(r"^.*[\\/]")
        self.snapshot_tuple = self.parse_string_to_table()
        self.disk_name = self.get_snapshot_name().split("@")[0]

    def __repr__(self):
        return self.get_snapshot_name()

    def get_snapshot_string(self):
        return self.snapshot_string

    def parse_string_to_table(self):
        array = re.split(self.re_split_tabs, self.snapshot_string)
        return tuple(array)

    def get_snapshot_name(self):
        name_str = self.snapshot_tuple[0]
        name = next(self.re_name.finditer(name_str))
        return name.group()

    def get_snapshot_zvol(self):
        name_str = self.snapshot_tuple[0]
        zvol = next(self.re_zvol.finditer(name_str))
        return zvol.group()

    def get_snapshot_creation_time(self):
        time_epoch = int(self.snapshot_tuple[1])
        return str(datetime.datetime.utcfromtimestamp(time_epoch))

    def get_snapshot_used_size(self):
        used_str = self.snapshot_tuple[2]
        return self.sizeof_fmt(int(used_str))

    def get_snapshot_referenced_size(self):
        referenced_str = self.snapshot_tuple[3]
        return self.sizeof_fmt(int(referenced_str))

    def get_disk_name(self):
        return self.disk_name

    @staticmethod
    def sizeof_fmt(num, suffix='B'):
    ## FIXME WOW taken from stack but it's too fucking slow. Probably because of division. Have to profile
        for unit in ['','Ki','Mi','Gi','Ti','Pi','Ei','Zi']:
            if abs(num) < 1024.0:
                return "%3.1f%s%s" % (num, unit, suffix)
            num /= 1024.0
        return "%.1f%s%s" % (num, 'Yi', suffix)