From 59e82ec9ee378255b95169ded6ae4af90dd687e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maxime=20=E2=80=9Cpep=E2=80=9D=20Buquet?= <pep@bouah.net>
Date: Mon, 12 Jul 2021 23:25:57 +0200
Subject: [PATCH] echo_bot: implement basic commands
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Signed-off-by: Maxime “pep” Buquet <pep@bouah.net>
---
 examples/echo_client.py | 58 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 56 insertions(+), 2 deletions(-)

diff --git a/examples/echo_client.py b/examples/echo_client.py
index 9820aa6..16df8ca 100644
--- a/examples/echo_client.py
+++ b/examples/echo_client.py
@@ -11,6 +11,7 @@
 """
 
 import os
+import re
 import sys
 import asyncio
 import logging
@@ -27,6 +28,10 @@ from omemo.exceptions import MissingBundleException
 
 log = logging.getLogger(__name__)
 
+# Used by the EchoBot
+LEVEL_DEBUG = 0
+LEVEL_ERROR = 1
+
 
 class EchoBot(ClientXMPP):
 
@@ -39,10 +44,15 @@ class EchoBot(ClientXMPP):
     """
 
     eme_ns = 'eu.siacs.conversations.axolotl'
+    cmd_prefix = '!'
+    debug_level: int = LEVEL_DEBUG  # or LEVEL_ERROR
 
     def __init__(self, jid, password):
         ClientXMPP.__init__(self, jid, password)
 
+        self.prefix_re: re.Pattern = re.compile('^%s' % self.cmd_prefix)
+        self.cmd_re: re.Pattern = re.compile('^%s(?P<command>\w+)(?:\s+(?P<args>.*))?' % self.cmd_prefix)
+
         self.add_event_handler("session_start", self.start)
         self.add_event_handler("message", self.message_handler)
 
@@ -62,6 +72,46 @@ class EchoBot(ClientXMPP):
         self.send_presence()
         self.get_roster()
 
+    def is_command(self, body: str) -> bool:
+        return self.prefix_re.match(body) is not None
+
+    async def handle_command(self, mto: JID, mtype: str, body: str) -> None:
+        match = self.cmd_re.match(body)
+        if match is None:
+            return None
+
+        groups = match.groupdict()
+        cmd = groups['command']
+        # args = groups['args']
+
+        if cmd == 'help':
+            await self.cmd_help(mto, mtype)
+        elif cmd == 'verbose':
+            await self.cmd_verbose(mto, mtype)
+        elif cmd == 'error':
+            await self.cmd_error(mto, mtype)
+
+        return None
+
+    async def cmd_help(self, mto: JID, mtype: str) -> None:
+        body = (
+            'I\'m the slixmpp-omemo echo bot! '
+            'The following commands are available:\n'
+            '{prefix}verbose Send message or reply with log messages\n'
+            '{prefix}error Send message or reply only on error\n'
+        ).format(prefix=self.cmd_prefix)
+        return await self.encrypted_reply(mto, mtype, body)
+
+    async def cmd_verbose(self, mto: JID, mtype: str) -> None:
+        self.debug_level = LEVEL_DEBUG
+        body = '''Debug level set to 'verbose'.'''
+        return await self.encrypted_reply(mto, mtype, body)
+
+    async def cmd_error(self, mto: JID, mtype: str) -> None:
+        self.debug_level = LEVEL_ERROR
+        body = '''Debug level set to 'error'.'''
+        return await self.encrypted_reply(mto, mtype, body)
+
     def message_handler(self, msg: Message) -> None:
         asyncio.ensure_future(self.message(msg))
 
@@ -84,14 +134,18 @@ class EchoBot(ClientXMPP):
             return None
 
         if not self['xep_0384'].is_encrypted(msg):
-            await self.plain_reply(mto, mtype, 'Echo unencrypted message:%(body)s' % msg)
+            if self.debug_level == LEVEL_DEBUG:
+                await self.plain_reply(mto, mtype, 'Echo unencrypted message:%(body)s' % msg)
             return None
 
         try:
             encrypted = msg['omemo_encrypted']
             body = self['xep_0384'].decrypt_message(encrypted, mfrom, allow_untrusted)
             decoded = body.decode('utf8')
-            await self.encrypted_reply(mto, mtype, 'Echo: %s' % decoded)
+            if self.is_command(decoded):
+                await self.handle_command(mto, mtype, decoded)
+            elif self.debug_level == LEVEL_DEBUG:
+                await self.encrypted_reply(mto, mtype, 'Echo: %s' % decoded)
             return None
         except (MissingOwnKey,):
             # The message is missing our own key, it was not encrypted for