From a1b7d0b1ab2ad63a26616b54a7fc64b035f4334b Mon Sep 17 00:00:00 2001
From: Ville Ranki <ville.ranki@iki.fi>
Date: Mon, 9 Dec 2019 20:24:51 +0200
Subject: [PATCH] Added echo module

---
 README.md       |  9 ++++++
 bot.py          | 77 +++++++++++++++++++++++++++++++++++++++++++++----
 modules/echo.py | 16 ++++++++++
 3 files changed, 96 insertions(+), 6 deletions(-)
 create mode 100644 modules/echo.py

diff --git a/README.md b/README.md
index 0de54d1..c52632e 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,14 @@
 # Hemppa - generic Matrix bot
 
+## Module list
+
+Write !modulename in Matrix room where the bot is to use modules.
+
+### Echo
+
+Simple example module that just echoes what user said. Can be used as an
+example for writing own modules.
+
 ## First
 
 * Create a Matrix user
diff --git a/bot.py b/bot.py
index 210e5d6..4037f56 100755
--- a/bot.py
+++ b/bot.py
@@ -1,14 +1,20 @@
 import asyncio
 import os
 import json
+import glob
+import traceback
+import importlib
+import sys
+import re
 from nio import (AsyncClient, RoomMessageText, RoomMessageUnknown, JoinError, InviteEvent)
 
 
 class Bot:
     client = None
     join_on_invite = False
+    modules = dict()
 
-    async def send_html(self, body, client, room):
+    async def send_text(self, room, body):
         msg = {
             "body": body,
             "msgtype": "m.text"
@@ -16,14 +22,29 @@ class Bot:
         await self.client.room_send(self.get_room_id(room), 'm.room.message', msg)
 
     def get_room_id(self, room):
-        for roomid in client.rooms:
+        for roomid in self.client.rooms:
             if self.client.rooms[roomid].named_room_name() == room.named_room_name():
                 return roomid
         print('Cannot find id for room', room.named_room_name(), ' - is the bot on it?')
         return None
 
     async def message_cb(self, room, event):
-        pass
+        # Figure out the command
+        body = event.body
+        if len(body) == 0:
+            return
+        command = body.split().pop(0)
+
+        # Strip away non-alphanumeric characters, including leading ! for security
+        command = re.sub(r'\W+', '', command)
+
+        moduleobject = self.modules.get(command)
+
+        if "matrix_message" in dir(moduleobject):
+            try:
+                await moduleobject.matrix_message(bot, room, event)
+            except:
+                traceback.print_exc(file=sys.stderr)
 
     async def unknown_cb(self, room, event):
         if event.msgtype != 'm.location':
@@ -40,15 +61,56 @@ class Bot:
             else:
                 break
 
+    def load_module(self, modulename):
+        try:
+            module = importlib.import_module('modules.' + modulename)
+            cls = getattr(module, 'MatrixModule')
+            return cls()
+        except ModuleNotFoundError:
+            print('Module ', modulename, ' failed to load!')
+            traceback.print_exc(file=sys.stderr)
+            return None
+
+    def get_modules(self):
+        modulefiles = glob.glob('./modules/*.py')
+
+        for modulefile in modulefiles:
+            modulename = os.path.splitext(os.path.basename(modulefile))[0]
+            moduleobject = self.load_module(modulename)
+            if moduleobject:
+                self.modules[modulename] = moduleobject
+
     def init(self):
         self.client = AsyncClient(os.environ['MATRIX_SERVER'], os.environ['MATRIX_USER'])
         self.client.access_token = os.getenv('MATRIX_ACCESS_TOKEN')
         self.join_on_invite = os.getenv('JOIN_ON_INVITE')
 
+        self.get_modules()
+
+        print(f'Starting {len(self.modules)} modules..')
+
+        for modulename, moduleobject in self.modules.items():
+            print(modulename + '..')
+            if "matrix_start" in dir(moduleobject):
+                try:
+                    moduleobject.matrix_start(bot)
+                except:
+                    traceback.print_exc(file=sys.stderr)
+    
+    def stop(self):
+        print(f'Stopping {len(self.modules)} modules..')
+        for modulename, moduleobject in self.modules.items():
+            print(modulename + '..')
+            if "matrix_stop" in dir(moduleobject):
+                try:
+                    moduleobject.matrix_stop(bot)
+                except:
+                    traceback.print_exc(file=sys.stderr)
+
     async def run(self):
         if not self.client.access_token:
             await self.client.login(os.environ['MATRIX_PASSWORD'])
-            print("Logged in with password, access token:", client.access_token)
+            print("Logged in with password, access token:", self.client.access_token)
 
         await self.client.sync()
 
@@ -66,5 +128,8 @@ class Bot:
 
 bot = Bot()
 bot.init()
-
-asyncio.get_event_loop().run_until_complete(bot.run())
+try:
+    asyncio.get_event_loop().run_until_complete(bot.run())
+except KeyboardInterrupt:
+    pass
+bot.stop()
diff --git a/modules/echo.py b/modules/echo.py
new file mode 100644
index 0000000..a697b3e
--- /dev/null
+++ b/modules/echo.py
@@ -0,0 +1,16 @@
+class MatrixModule:
+    def matrix_start(self, bot):
+        print("Echo start!")
+
+    def matrix_stop(self, bot):
+        print("Echo stop!")
+
+    async def matrix_message(self, bot, room, event):
+        args = event.body.split()
+        args.pop(0)
+
+        # Echo what they said back
+        await bot.send_text(room, ' '.join(args))
+
+    def help(self):
+        return('Echoes back what user has said')