From e4eafb5dd8a317a312605539ecd884366d7b9b89 Mon Sep 17 00:00:00 2001
From: Daniel Tsvetkov <danieltcv@gmail.com>
Date: Thu, 12 Dec 2019 17:01:33 +0100
Subject: [PATCH] added time library

---
 src/tww/time_lib.py | 263 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 263 insertions(+)
 create mode 100644 src/tww/time_lib.py

diff --git a/src/tww/time_lib.py b/src/tww/time_lib.py
new file mode 100644
index 0000000..20dcb82
--- /dev/null
+++ b/src/tww/time_lib.py
@@ -0,0 +1,263 @@
+import datetime
+import os
+from datetime import datetime, timedelta
+
+import pytz
+from dateparser import parse as parse_dt
+from dateparser.timezone_parser import StaticTzInfo
+from dateutil.tz import tzlocal, gettz
+from tww import parse_query, solve_query, TZ_OFFSETS
+
+
+def tzinfo_from_offset(offset):
+    if ':' in offset:
+        ''.join(offset.split(':'))
+    tznames = TZ_OFFSETS.get(offset)
+    if not tznames:
+        return pytz.timezone("utc")
+    for tzname in tznames:
+        if tzname.startswith('Etc/GMT'):
+            return pytz.timezone(tzname)
+    return pytz.timezone(tznames[0])
+
+
+def time_ago(date=None, diff=None):
+    """
+    Get a datetime object, timedelta object or a int() Epoch timestamp and return a
+    pretty string like 'an hour ago', 'Yesterday', '3 months ago',
+    'just now', etc
+    Modified from: http://stackoverflow.com/a/1551394/141084
+    """
+    now = get_utcnow()
+    if not date:
+        if diff:
+            diff = timedelta(seconds=diff)
+        else:
+            diff = now - now
+    else:
+        if type(date) is str:
+            parsed_dt = parse_dt(date)
+            if parsed_dt.tzinfo is not None:
+                now = get_utcnow(tzaware=True)
+            diff = now - parsed_dt
+        elif type(date) is timedelta:
+            diff = date
+        elif type(date) is int:
+            diff = now - datetime.fromtimestamp(date)
+        elif isinstance(date, datetime):
+            if date.tzinfo is not None:
+                now = get_utcnow(tzaware=True)
+            diff = now - date
+        else:
+            raise ValueError('invalid date %s of type %s' % (date, type(date)))
+
+    sign = ''
+    if diff.days < 0:
+        diff = -diff
+        sign = '-'
+    second_diff = diff.seconds
+    day_diff = diff.days
+
+    if day_diff == 0:
+        if second_diff < 60:
+            return str("{}{:02d}".format(sign, second_diff))
+        seconds = second_diff % 60
+        if second_diff < 3600:
+            min_diff = second_diff // 60
+            return str("{}{:02d}:{:02d}".format(sign, min_diff, seconds))
+        minutes = second_diff % 3600 // 60
+        if second_diff < 86400:
+            hrs_diff = second_diff // 3600
+            return str("{}{:02d}:{:02d}:{:02d}".format(sign, hrs_diff, minutes, seconds))
+    seconds = second_diff % 60
+    minutes = second_diff % 3600 // 60
+    hours = second_diff // 3600
+    if day_diff < 365:
+        if day_diff < 30:
+            return str("{}{}d{:02d}:{:02d}:{:02d}".format(sign, day_diff, hours, minutes, seconds))
+        months, days = day_diff // 30, day_diff % 30
+        return str("{}{}m{}d{:02d}:{:02d}:{:02d}".format(sign, months, days, hours, minutes, seconds))
+    years = day_diff // 365
+    days = day_diff % 365
+    months, days = days // 30, days % 30
+    return str("{}{}y{}m{}d{:02d}:{:02d}:{:02d}".format(sign, years, months, days, hours, minutes, seconds))
+
+
+def query_to_dt(query):
+    human_dt, human_tz_loc = parse_query(query)
+    return solve_query(human_dt, human_tz_loc)
+
+
+# ==================
+def dateparser_parse_dt(s: str):
+    print("Dateparser query: {}".format(s))
+    parsed = parse_dt(s)
+    print("Dateparser parsed query: {}".format(parsed))
+    return parsed
+
+
+def get_utcnow(tzaware: bool = False):
+    if tzaware:
+        return datetime.utcnow().replace(tzinfo=pytz.UTC)
+    return datetime.utcnow()
+
+
+def dt_tz_translation(dt: datetime, to_tz: str, from_tz: str = "+00:00"):
+    if ':' in to_tz:
+        to_shh, to_mm = to_tz.split(':')
+    else:
+        to_shh, to_mm = to_tz[:-2], to_tz[-2:]
+    if ':' in from_tz:
+        from_shh, from_mm = from_tz.split(':')
+    else:
+        from_shh, from_mm = from_tz[:-2], to_tz[-2:]
+    tzinfo = tzinfo_from_offset(to_tz)
+    if dt.tzinfo:
+        return dt.astimezone(tzinfo)
+    r_dt = dt + timedelta(hours=int(to_shh), minutes=int(to_mm)) - timedelta(hours=int(from_shh), minutes=int(from_mm))
+    r_dt.replace(tzinfo=tzinfo)
+    return r_dt
+
+
+def format_offset_from_timedelta(tdelta: timedelta):
+    sign = "+" if tdelta.seconds >= 0 else "-"
+    h = tdelta.seconds // 3600
+    m = (tdelta.seconds // 60) - h * 60
+    return "{}{:02d}:{:02d}".format(sign, h, m)
+
+
+def get_local_tzname_iana():
+    return '/'.join(os.path.realpath(gettz()._filename).split('/')[-2:])
+
+
+def get_local_tz_offset():
+    return format_offset_from_timedelta(datetime.now(tzlocal()).tzinfo._std_offset)
+
+
+def tzname_to_tz_offset(tzname_iana: str):
+    return format_offset_from_timedelta(pytz.timezone(tzname_iana).utcoffset(get_utcnow()))
+
+
+def get_dt_tz_offset(dt: datetime):
+    if dt.tzinfo is not None:
+        if type(dt.tzinfo) is StaticTzInfo:
+            tzoffset = dt.tzinfo._StaticTzInfo__offset
+        else:
+            tzoffset = dt.tzinfo._utcoffset
+        return format_offset_from_timedelta(tzoffset)
+    return "+00:00"
+
+
+def get_seconds_since_epoch(dt):
+    return int(dt.timestamp())
+
+
+def epoch_to_dt(seconds):
+    return datetime.fromtimestamp(seconds)
+
+
+def time_to_emoji(dt):
+    seconds = get_seconds_since_epoch(dt)
+    a = int((seconds / 900 - 3) / 2 % 24)
+    return chr(128336 + a // 2 + a % 2 * 12)
+
+
+if __name__ == "__main__":
+    print(get_local_tzname_iana())
+
+    print(get_local_tz_offset())
+
+    print(tzname_to_tz_offset(
+        get_local_tzname_iana()
+    ))
+
+    print(dt_tz_translation(
+        get_utcnow(),
+        get_local_tz_offset()
+    ))
+
+    print(time_to_emoji(
+        dt_tz_translation(
+            get_utcnow(),
+            get_local_tz_offset()
+        )
+    ))
+
+    print(get_seconds_since_epoch(
+        dateparser_parse_dt("2019-12-11 15:53:40+0000")
+    ))
+
+    # QUERIES....
+
+    "<TIME>"
+    "================="
+    "2019-12-12T03:14:15"  # ISO-8601 Naive time
+    "2019-12-12T03:14:15+0000"  # ISO-8601 Timezone aware
+    "in 3 hours"  # Time:relative:future
+    "5 days ago"  # Time:relative:past
+
+    "<TIME> IN <WHEREVER>"
+    "================="
+    "Now in epoch"  # Absolute:Epoch
+    "Now in New York"  # Location:City
+    "Now in Bulgaria"  # Location:Country
+    "Now in USA"  # Location:Country       - multiple timezones
+    "Now in CET"  # Timezone:Abbreviation  - https://en.wikipedia.org/wiki/List_of_time_zone_abbreviations
+    "Now in Europe/Zurich"  # Timezone:IANA          - tz db, https://en.wikipedia.org/wiki/List_of_tz_database_time_zones, timezone database
+    "Now in Alfa"  # Timezone:Military      - https://en.wikipedia.org/wiki/List_of_military_time_zones
+    "Now in +02:00"  # Timezone:Offset        - https://en.wikipedia.org/wiki/List_of_UTC_time_offsets
+
+    "<TIMEDELTA>"
+    "================="
+    "Time since <TIME>"  # Timedelta:past
+    "Time until <TIME>"  # Timedelta:future
+
+    # strptime: str -> datetime
+    # strftime: datetime -> str
+
+    #     %Y  Year with century as a decimal number.
+    #     %m  Month as a decimal number [01,12].
+    #     %d  Day of the month as a decimal number [01,31].
+    #     %H  Hour (24-hour clock) as a decimal number [00,23].
+    #     %M  Minute as a decimal number [00,59].
+    #     %S  Second as a decimal number [00,61].
+    #     %z  Time zone offset from UTC.
+    #     %a  Locale's abbreviated weekday name.
+    #     %A  Locale's full weekday name.
+    #     %b  Locale's abbreviated month name.
+    #     %B  Locale's full month name.
+    #     %c  Locale's appropriate date and time representation.
+    #     %I  Hour (12-hour clock) as a decimal number [01,12].
+    #     %p  Locale's equivalent of either AM or PM.
+
+    # https://docs.python.org/3/library/datetime.html
+    #
+    # %a		Weekday as locale’s abbreviated name.		                           "Sun, Mon, …, Sat (en_US); So, Mo, …, Sa (de_DE)
+    # %A		Weekday as locale’s full name.		                                    Sunday, Monday, …, Saturday (en_US);	Sonntag, Montag, …, Samstag (de_DE)
+    # %w		Weekday as a decimal number, where 0 is Sunday and 6 is Saturday.		0, 1, …, 6
+    # %d		Day of the month as a zero-padded decimal number.	                   	01, 02, …, 31
+    # %b		Month as locale’s abbreviated name.		                                Jan, Feb, …, Dec (en_US);	Jan, Feb, …, Dez (de_DE)
+    # %B		Month as locale’s full name.	                                    	January, February, …, December (en_US);	Januar, Februar, …, Dezember (de_DE)
+    # %m		Month as a zero-padded decimal number.	                            	01, 02, …, 12
+    # %y		Year without century as a zero-padded decimal number.	            	00, 01, …, 99
+    # %Y		Year with century as a decimal number.		                            0001, 0002, …, 2013, 2014, …, 9998, 9999
+    # %H		Hour (24-hour clock) as a zero-padded decimal number.	            	00, 01, …, 23
+    # %I		Hour (12-hour clock) as a zero-padded decimal number.	            	01, 02, …, 12
+    # %p		Locale’s equivalent of either AM or PM.		                            AM, PM (en_US);	am, pm (de_DE)
+    # %M		Minute as a zero-padded decimal number.		                            00, 01, …, 59
+    # %S		Second as a zero-padded decimal number.		                            00, 01, …, 59
+    # %f		Microsecond as a decimal number, zero-padded on the left.		        000000, 000001, …, 999999
+    # %z		UTC offset in the form ±HHMM[SS[.ffffff]]
+    #           (empty string if the object is naive).	                            	(empty), +0000, -0400, +1030, +063415, -030712.345216
+    # %Z		Time zone name (empty string if the object is naive).		            (empty), UTC, EST, CST
+    # %j		Day of the year as a zero-padded decimal number.		                001, 002, …, 366
+    # %U		Week number of the year (Sunday as the first day of the week)
+    #           as a zero padded decimal number. All days in a new year
+    #           preceding the first Sunday are considered to be in week                 0.		00, 01, …, 53
+    # %W		Week number of the year (Monday as the first day of the week)
+    #           as a decimal number. All days in a new year preceding the
+    #           first Monday are considered to be in week 0.	            	        00, 01, …, 53
+    # %c		Locale’s appropriate date and time representation.		                Tue Aug 16 21:30:00 1988 (en_US);	Di 16 Aug 21:30:00 1988 (de_DE)
+    # %x		Locale’s appropriate date representation.	                           	08/16/1988 (en_US);	16.08.1988 (de_DE)
+    # %X		Locale’s appropriate time representation.	                        	21:30:00 (en_US);	21:30:00 (de_DE)
+    # %%		A literal '%' character.	                                        	%