Allow datetime in limit parameters for logs_from.

Add time_snowflake to convert a datetime to a "snowflake".

discord/client.py

@@ -51,6 +51,7 @@ import logging, traceback
 import sys, re
 import tempfile, os, hashlib
 import itertools
+import datetime
 from random import randint as random_integer
 
 PY35 = sys.version_info >= (3, 5)
@@ -1167,10 +1168,12 @@ class Client:
             The channel to obtain the logs from.
         limit : int
             The number of messages to retrieve.
-        before : :class:`Message`
-            The message before which all returned messages must be.
-        after : :class:`Message`
-            The message after which all returned messages must be.
+        before : :class:`Message` or `datetime`
+            The message or date before which all returned messages must be.
+            If a date is provided it must be a timezone-naive datetime representing UTC time.
+        after : :class:`Message` or `datetime`
+            The message or date after which all returned messages must be.
+            If a date is provided it must be a timezone-naive datetime representing UTC time.
 
         Raises
         ------
@@ -1210,9 +1213,15 @@ class Client:
         }
 
         if before:
-            params['before'] = before.id
+            if isinstance(before, datetime.datetime):
+                params['before'] = utils.time_snowflake(before, high=False)
+            else:
+                params['before'] = before.id
         if after:
-            params['after'] = after.id
+            if isinstance(after, datetime.datetime):
+                params['after'] = utils.time_snowflake(after, high=True)
+            else:
+                params['after'] = after.id
 
         response = yield from self.session.get(url, params=params, headers=self.headers)
         log.debug(request_logging_format.format(method='GET', response=response))

discord/utils.py

@@ -106,6 +106,24 @@ def snowflake_time(id):
     """Returns the creation date in UTC of a discord id."""
     return datetime.datetime.utcfromtimestamp(((int(id) >> 22) + DISCORD_EPOCH) / 1000)
 
+def time_snowflake(datetime_obj, high=False):
+    """Returns a numeric snowflake pretending to be created at the given date.
+
+    When using as the lower end of a range, use time_snowflake(high=False) - 1 to be inclusive, high=True to be exclusive
+    When using as the higher end of a range, use time_snowflake(high=True) + 1 to be inclusive, high=False to be exclusive
+
+    Parameters
+    -----------
+    datetime_obj
+        A timezone-naive datetime object representing UTC time.
+    high
+        Whether or not to set the lower 22 bit to high or low.
+    """
+    unix_seconds = (datetime_obj - type(datetime_obj)(1970, 1, 1)).total_seconds()
+    discord_millis = int(unix_seconds * 1000 - DISCORD_EPOCH)
+
+    return (discord_millis << 22) + (2**22-1 if high else 0)
+
 def find(predicate, seq):
     """A helper to return the first element found in the sequence
     that meets the predicate. For example: ::