From e3f40c4beede1df1296288aa13d84787c9cd11eb Mon Sep 17 00:00:00 2001
From: Alex Root Junior <jroot.junior@gmail.com>
Date: Fri, 26 May 2017 10:55:07 +0300
Subject: [PATCH] Add skeleton for Dispatcher.

---
 aiogram/dispatcher/__init__.py | 62 ++++++++++++++++++++++++++++++++++
 aiogram/dispatcher/handler.py  | 44 ++++++++++++++++++++++++
 2 files changed, 106 insertions(+)
 create mode 100644 aiogram/dispatcher/__init__.py
 create mode 100644 aiogram/dispatcher/handler.py

diff --git a/aiogram/dispatcher/__init__.py b/aiogram/dispatcher/__init__.py
new file mode 100644
index 00000000..d99775a8
--- /dev/null
+++ b/aiogram/dispatcher/__init__.py
@@ -0,0 +1,62 @@
+import asyncio
+import logging
+
+from .handler import Handler
+from ..bot import AIOGramBot
+
+log = logging.getLogger(__name__)
+
+
+class Dispatcher:
+    def __init__(self, bot):
+        self.bot: AIOGramBot = bot
+
+        self.last_update_id = 0
+        self.updates = Handler(self)
+        self.messages = Handler(self)
+        self.commands = Handler(self)
+
+        self.updates.register(self.process_update)
+
+        self._pooling = False
+
+    async def skip_updates(self):
+        total = 0
+        updates = await self.bot.get_updates(offset=self.last_update_id, timeout=1)
+        while updates:
+            total += len(updates)
+            for update in updates:
+                if update.update_id > self.last_update_id:
+                    self.last_update_id = update.update_id
+            updates = await self.bot.get_updates(offset=self.last_update_id + 1, timeout=1)
+        return total
+
+    async def process_updates(self, updates):
+        for update in updates:
+            self.bot.loop.create_task(self.updates.notify(update))
+
+    async def process_update(self, update):
+        if update.message:
+            await self.messages.notify(update.message)
+
+    async def start_pooling(self, timeout=20, relax=0.1):
+        if self._pooling:
+            raise RuntimeError('Pooling already started')
+        self._pooling = True
+        offset = None
+        while self._pooling:
+            try:
+                updates = await self.bot.get_updates(offset=offset, timeout=timeout)
+            except Exception as e:
+                log.exception('Cause exception while getting updates')
+                await asyncio.sleep(relax)
+                continue
+
+            if updates:
+                offset = updates[-1].update_id + 1
+                await self.process_updates(updates)
+
+            await asyncio.sleep(relax)
+
+    def stop_pooling(self):
+        self._pooling = False
diff --git a/aiogram/dispatcher/handler.py b/aiogram/dispatcher/handler.py
new file mode 100644
index 00000000..006c199e
--- /dev/null
+++ b/aiogram/dispatcher/handler.py
@@ -0,0 +1,44 @@
+import inspect
+
+
+async def check_filter(filter_, args, kwargs):
+    if inspect.iscoroutinefunction(filter_):
+        return await filter_(*args, **kwargs)
+    elif callable(filter_):
+        return filter_(*args, **kwargs)
+    else:
+        return True
+
+
+async def check_filters(filters, args, kwargs):
+    if filters is not None:
+        for filter_ in filters:
+            f = await check_filter(filter_, args, kwargs)
+            if not f:
+                return False
+    return True
+
+
+class Handler:
+    def __init__(self, dispatcher):
+        self.dispatcher = dispatcher
+
+        self.handlers = []
+
+    def register(self, handler, filters=None):
+        if filters and not isinstance(filters, (list, tuple, set)):
+            filters = [filters]
+        self.handlers.append((filters, handler))
+
+    def unregister(self, handler):
+        for handler_with_filters in self.handlers:
+            _, registered = handler_with_filters
+            if handler is registered:
+                self.handlers.remove(handler_with_filters)
+                return True
+        raise ValueError('This handler is not registered!')
+
+    async def notify(self, *args, **kwargs):
+        for filters, handler in self.handlers:
+            if await check_filters(filters, args, kwargs):
+                await handler(*args, **kwargs)