[V3] Report Tool (#1281)

* Okay, let's fix the issues here hopefully.

* This is working now

* Unfinished, and needs a lot of testing.

* more work

* working

* minor thing to remove

* improve i18n and usage feedback

redbot/core/utils/antispam.py

@@ -0,0 +1,62 @@
+from datetime import datetime, timedelta
+from typing import Tuple, List
+from collections import namedtuple
+
+Interval = Tuple[timedelta, int]
+AntiSpamInterval = namedtuple('AntiSpamInterval', ['period', 'frequency'])
+
+
+class AntiSpam:
+    """
+    Custom class which is more flexible than using discord.py's
+    `commands.cooldown()`
+
+    Can be intialized with a custom set of intervals
+    These should be provided as a list of tuples in the form
+    (timedelta, quantity)
+
+    Where quantity represents the maximum amount of times
+    something should be allowed in an interval.
+    """
+    # TODO : Decorator interface for command check using `spammy`
+    # with insertion of the antispam element into context
+    # for manual stamping on succesful command completion
+
+    default_intervals = [
+        (timedelta(seconds=5), 3),
+        (timedelta(minutes=1), 5),
+        (timedelta(hours=1), 10),
+        (timedelta(days=1), 24)
+    ]
+
+    def __init__(self, intervals: List[Interval]):
+        self.__event_timestamps = []
+        _itvs = intervals if intervals else self.default_intervals
+        self.__intervals = [
+            AntiSpamInterval(*x) for x in _itvs
+        ]
+        self.__discard_after = max([x.period for x in self.__intervals])
+
+    def __interval_check(self, interval: AntiSpamInterval):
+        return len(
+            [t for t in self.__event_timestamps
+             if (t + interval.period) > datetime.utcnow()]
+        ) >= interval.frequency
+
+    @property
+    def spammy(self):
+        """
+        use this to check if any interval criteria are met
+        """
+        return any(self.__interval_check(x) for x in self.__intervals)
+
+    def stamp(self):
+        """
+        Use this to mark an event that counts against the intervals
+        as happening now
+        """
+        self.__event_timestamps.append(datetime.utcnow())
+        self.__event_timestamps = [
+            t for t in self.__event_timestamps
+            if t + self.__discard_after > datetime.utcnow()
+        ]