1 files changed, 133 insertions, 0 deletions
diff --git a/vk/tracking/online_sessions.py b/vk/tracking/online_sessions.py
new file mode 100644
index 0000000..debf1e6
--- /dev/null
+++ b/vk/tracking/online_sessions.py
@@ -0,0 +1,133 @@
+# Copyright 2016 Egor Tensin <Egor.Tensin@gmail.com>
+# This file is licensed under the terms of the MIT License.
+# See LICENSE.txt for details.
+
+from collections import OrderedDict
+from collections.abc import MutableMapping
+from datetime import timedelta
+from enum import Enum
+
+class Weekday(Enum):
+    MONDAY = 0
+    TUESDAY = 1
+    WEDNESDAY = 2
+    THURSDAY = 3
+    FRIDAY = 4
+    SATURDAY = 5
+    SUNDAY = 6
+
+    def __str__(self):
+        return self.name[0] + self.name[1:].lower()
+
+class OnlineSessionEnumerator(MutableMapping):
+    def __init__(self, time_from=None, time_to=None):
+        self._records = {}
+        self._time_from = time_from
+        self._time_to = time_to
+
+    def __getitem__(self, user):
+        return self._records[user]
+
+    def __setitem__(self, user, record):
+        self._records[user] = record
+
+    def __delitem__(self, user):
+        del self._records[user]
+
+    def __iter__(self):
+        return iter(self._records)
+
+    def __len__(self):
+        return len(self._records)
+
+    def _trim_or_drop_session(self, session):
+        user, started_at, ended_at = session
+        if self._time_from is not None:
+            if ended_at < self._time_from:
+                return None
+            if started_at < self._time_from:
+                started_at = self._time_from
+        if self._time_to is not None:
+            if started_at > self._time_to:
+                return None
+            if ended_at > self._time_to:
+                ended_at = self._time_to
+        return user, started_at, ended_at
+
+    def read_database(self, db_reader):
+        for record in db_reader:
+            session = self._process_database_record(record)
+            if session is not None:
+                session = self._trim_or_drop_session(session)
+            if session is not None:
+                yield session
+
+    def group_by_user(self, db_reader):
+        by_user = {}
+        for user, started_at, ended_at in self.read_database(db_reader):
+            if user not in by_user:
+                by_user[user] = timedelta()
+            by_user[user] += ended_at - started_at
+        return by_user
+
+    def group_by_date(self, db_reader):
+        by_date = {}
+        for _, started_at, ended_at in self.read_database(db_reader):
+            for date, duration in self._split_into_days(started_at, ended_at):
+                if date not in by_date:
+                    by_date[date] = timedelta()
+                by_date[date] += duration
+        return by_date
+
+    def group_by_weekday(self, db_reader):
+        by_weekday = OrderedDict()
+        for weekday in Weekday:
+            by_weekday[weekday] = timedelta()
+        for _, started_at, ended_at in self.read_database(db_reader):
+            for date, duration in self._split_into_days(started_at, ended_at):
+                by_weekday[Weekday(date.weekday())] += duration
+        return by_weekday
+
+    def group_by_hour(self, db_reader):
+        by_hour = OrderedDict()
+        for i in range(24):
+            by_hour[i] = timedelta()
+        for _, started_at, ended_at in self.read_database(db_reader):
+            for hour, duration in self._split_into_hours(started_at, ended_at):
+                by_hour[hour] += duration
+        return by_hour
+
+    @staticmethod
+    def _split_into_days(a, b):
+        while a.date() != b.date():
+            next_day = a.date() + timedelta(days=1)
+            yield a.date(), next_day - a
+            a = next_day
+        yield b.date(), b - a
+
+    @staticmethod
+    def _split_into_hours(a, b):
+        while a.date() != b.date() or a.hour != b.hour:
+            next_hour = a.replace(minute=0, second=0) + timedelta(hours=1)
+            yield a.hour, next_hour - a
+            a = next_hour
+        yield b.hour, b - a
+
+    def _process_database_record(self, record):
+        return self._close_user_session(record.to_user())
+
+    def _known_user(self, user):
+        return user.get_uid() in self._records
+
+    def _unknown_user(self, user):
+        return not self._known_user(user)
+
+    def _close_user_session(self, user):
+        if user not in self or self[user].is_offline():
+            self[user] = user
+            return None
+        if user.is_online():
+            return None
+        session = user, self[user].get_last_seen_time(), user.get_last_seen_time()
+        self[user] = user
+        return session