1# -*- coding: utf-8 -*-
2"""Cocoa timestamp implementation."""
3
4import decimal
5
6from dfdatetime import definitions
7from dfdatetime import factory
8from dfdatetime import interface
9
10
11class CocoaTimeEpoch(interface.DateTimeEpoch):
12  """Cocoa time epoch."""
13
14  def __init__(self):
15    """Initializes a Cocoa time epoch."""
16    super(CocoaTimeEpoch, self).__init__(2001, 1, 1)
17
18
19class CocoaTime(interface.DateTimeValues):
20  """Cocoa timestamp.
21
22  The Cocoa timestamp is a floating point value that contains the number of
23  seconds since 2001-01-01 00:00:00 (also known as the Cocoa epoch).
24  Negative values represent date and times predating the Cocoa epoch.
25
26  Attributes:
27    is_local_time (bool): True if the date and time value is in local time.
28  """
29  # The difference between January 1, 2001 and January 1, 1970 in seconds.
30  _COCOA_TO_POSIX_BASE = -978307200
31
32  _EPOCH = CocoaTimeEpoch()
33
34  def __init__(self, time_zone_offset=None, timestamp=None):
35    """Initializes a Cocoa timestamp.
36
37    Args:
38      time_zone_offset (Optional[int]): time zone offset in number of minutes
39          from UTC or None if not set.
40      timestamp (Optional[float]): Cocoa timestamp.
41    """
42    super(CocoaTime, self).__init__(time_zone_offset=time_zone_offset)
43    self._precision = definitions.PRECISION_1_SECOND
44    self._timestamp = timestamp
45
46  @property
47  def timestamp(self):
48    """float: Cocoa timestamp or None if not set."""
49    return self._timestamp
50
51  def _GetNormalizedTimestamp(self):
52    """Retrieves the normalized timestamp.
53
54    Returns:
55      float: normalized timestamp, which contains the number of seconds since
56          January 1, 1970 00:00:00 and a fraction of second used for increased
57          precision, or None if the normalized timestamp cannot be determined.
58    """
59    if self._normalized_timestamp is None:
60      if self._timestamp is not None:
61        self._normalized_timestamp = (
62            decimal.Decimal(self._timestamp) - self._COCOA_TO_POSIX_BASE)
63
64        if self._time_zone_offset:
65          self._normalized_timestamp -= self._time_zone_offset * 60
66
67    return self._normalized_timestamp
68
69  def CopyFromDateTimeString(self, time_string):
70    """Copies a Cocoa timestamp from a date and time string.
71
72    Args:
73      time_string (str): date and time value formatted as:
74          YYYY-MM-DD hh:mm:ss.######[+-]##:##
75
76          Where # are numeric digits ranging from 0 to 9 and the seconds
77          fraction can be either 3 or 6 digits. The time of day, seconds
78          fraction and time zone offset are optional. The default time zone
79          is UTC.
80
81    Raises:
82      ValueError: if the time string is invalid or not supported.
83    """
84    date_time_values = self._CopyDateTimeFromString(time_string)
85
86    year = date_time_values.get('year', 0)
87    month = date_time_values.get('month', 0)
88    day_of_month = date_time_values.get('day_of_month', 0)
89    hours = date_time_values.get('hours', 0)
90    minutes = date_time_values.get('minutes', 0)
91    seconds = date_time_values.get('seconds', 0)
92    microseconds = date_time_values.get('microseconds', None)
93    time_zone_offset = date_time_values.get('time_zone_offset', 0)
94
95    timestamp = self._GetNumberOfSecondsFromElements(
96        year, month, day_of_month, hours, minutes, seconds)
97    timestamp += self._COCOA_TO_POSIX_BASE
98
99    timestamp = float(timestamp)
100    if microseconds is not None:
101      timestamp += float(microseconds) / definitions.MICROSECONDS_PER_SECOND
102
103    self._normalized_timestamp = None
104    self._timestamp = timestamp
105    self._time_zone_offset = time_zone_offset
106
107  def CopyToDateTimeString(self):
108    """Copies the Cocoa timestamp to a date and time string.
109
110    Returns:
111      str: date and time value formatted as: YYYY-MM-DD hh:mm:ss.###### or
112          None if the timestamp cannot be copied to a date and time string.
113    """
114    if self._timestamp is None:
115      return None
116
117    number_of_days, hours, minutes, seconds = self._GetTimeValues(
118        int(self._timestamp))
119
120    year, month, day_of_month = self._GetDateValuesWithEpoch(
121        number_of_days, self._EPOCH)
122
123    microseconds = int(
124        (self._timestamp % 1) * definitions.MICROSECONDS_PER_SECOND)
125
126    return '{0:04d}-{1:02d}-{2:02d} {3:02d}:{4:02d}:{5:02d}.{6:06d}'.format(
127        year, month, day_of_month, hours, minutes, seconds, microseconds)
128
129
130factory.Factory.RegisterDateTimeValues(CocoaTime)
131