modular-bot-framework-for-telegram/main.py

from telegram.ext import Updater, MessageHandler, Filters
import datetime
import codecs
import time
import json
import sys
import os
import threading
import importlib

# global variables
STOP_REQUESTED = False


# some functions that increase readability of the code
def readfile(filename):
    try:
        return codecs.open(filename, encoding="utf-8").read()
    except FileNotFoundError:
        return False
    except Exception as e:
        print(f"[ERROR] Unexpected error occurred in readfile() ({e})")
        return False


# module object classes
class ModuleV1:
    def __init__(self, path, code, enabled, alias, predefine):
        self.version = 1
        self.enabled = enabled
        self.code = code
        self.alias = alias
        self.path = path
        self.predefine = predefine

        if self.predefine:
            self.set_predefine()

    # set environmental variables
    def set_env(self):
        self.RESPONSE = ""

    def set_predefine(self):
        try:
            exec(self.predefine)
        except Exception as e:
            print(f"[ERROR] module v1: module \"{self.path}\" ({self.alias}) raised exception \"{e}\" "
                  f"during predefine stage, disabling it...")

    # running the module
    def process(self, msg):
        self.set_env()

        self.MESSAGE = msg
        try:
            exec(self.code)
            return self.RESPONSE
        except Exception as e:
            print(f"[ERROR] module v1: module \"{self.path}\" ({self.alias}) raised exception \"{e}\"")
            return ""


class ModuleV2:
    def __init__(self, path, index_file, enabled, alias):
        self.version = 2
        self.enabled = enabled
        self.alias = alias
        self.path = path
        self.index_file = index_file[:-3]
        self.obj = importlib.import_module((path + self.index_file).replace("/", "."))

    # running the module
    def process(self, msg):
        try:
            return self.obj.process(msg, self.path)
        except Exception as e:
            print(f"[ERROR] module v2: module \"{self.path}\" ({self.alias}) raised exception \"{e}\"")
            return None


# module control unit
class ModuleControlUnit:
    def __init__(self):
        self.modules = []
        self.reload_modules()

        print("[INFO] ModuleControlUnit: initialized successfully")

    def reload_modules(self):
        for folder in os.listdir("modules/"):
            try:
                meta_raw = readfile("modules/{}/meta.json".format(folder))
                if not meta_raw:
                    print(f"[WARN] module_loader: no meta.json found in module folder \"{folder}\"")
                    continue

                meta = json.loads( meta_raw )
                if "version" in meta:
                    if meta["version"] == 1:
                        if "index_file" in meta:
                            index_file = meta["index_file"]
                        else:
                            index_file = "index.py"

                        code = readfile( "modules/{}/{}".format(folder, index_file) )
                        if not code: # False both when readfile() returns False and when the code string is empty
                            print("[WARN] reload_modules: module {} does not have any code, skipping...".format(folder))
                            continue

                        if "start_on_boot" in meta:
                            enabled = meta["start_on_boot"]
                        else:
                            enabled = False

                        if "alias" in meta:
                            alias = meta["alias"]
                        else:
                            alias = None

                        if "predefine" in meta:
                            predefine = readfile("modules/{}/{}".format(folder, meta["predefine"]))
                        else:
                            predefine = False

                        self.modules.append(ModuleV1(f"modules/{folder}/", code, enabled, alias, predefine))

                        print(f"[INFO] reload_modules: successfully loaded {folder} as {alias} "
                              f"(start_on_boot: {enabled})")

                    elif meta["version"] == 2:
                        if "index_file" in meta:
                            index_file = meta["index_file"]
                        else:
                            index_file = "index.py"

                        if "start_on_boot" in meta:
                            enabled = meta["start_on_boot"]
                        else:
                            enabled = False

                        if "alias" in meta:
                            alias = meta["alias"]
                        else:
                            alias = None

                        self.modules.append(ModuleV2(f"modules/{folder}/", index_file, enabled, alias))

                        print(f"[INFO] reload_modules: successfully loaded {folder} as {alias} "
                              f"(start_on_boot: {enabled})")

                    else:
                        print(f"[WARN] reload_modules: module {folder} requires unsupported version "
                              f"({meta['version']} > 2), skipping...")

            except Exception as e:
                print(f"[ERROR] module_loader: error while loading module \"{folder}\" ({e})")


# synchronous message processor
def queue_processor():
    while True:
        try:
            if len(message_queue) > 0:
                msg = message_queue[0]
                print("[DEBUG] queue_processor: {}".format(msg)) # debug

                # check for control commands
                if msg["chat"]["id"] == 575246355:
                    if msg["text"][0] == "$":
                        command = msg["text"][1:].split(" ")

                        if len(command) >= 2 and command[0] == "module":
                            if command[1] == "reload":
                                print("[INFO] Module reloading triggered by a command")

                                # properly reload all v2 modules
                                for mod in mcu.modules:
                                    if mod.version == 2:
                                        importlib.reload(mod.obj)

                                del mcu.modules[:]
                                mcu.reload_modules()

                        del message_queue[0]
                        continue

                # modules are used in here
                for mod in mcu.modules:
                    if mod.enabled:
                        if mod.version == 1 or mod.version == 2:
                            response = mod.process(msg)

                            if response:
                                # protecting output
                                symbols_to_escape = ['[', ']', '(', ')', '~', '`', '>', '#', '+', '-', '=', '|', '{', '}', '.', '!']
                                for symbol in symbols_to_escape:
                                    response = response.replace(symbol, f"\\{symbol}")

                                updater.bot.send_message(chat_id=msg.chat.id, text=response,
                                                         disable_web_page_preview=True,
                                                         parse_mode="MarkdownV2")
                                print(f"Responded using module {mod.path} ({mod.alias}) with text: {response}")
                                break

                del message_queue[0]

                time.sleep(0.1)
            else:
                if STOP_REQUESTED:
                    break
                else:
                    time.sleep(1)
        except Exception as e:
            print(f"[ERROR] queue_processor: current message queue: {message_queue}")
            print(f"[ERROR] queue_processor: error while processing message ({e}), trying to delete it...")
            try:
                del message_queue[0]
                print("[INFO] queue_processor: deleted broken message from the queue")
            except:
                print("[WARN] queue_processor: message seems absent, whatever")

    print("[INFO] queue_processor thread stops successfully")


# telegram bot processor
def message_handler(update, context):
    print("[DEBUG] Received new message")  # just for testing
    message_queue.append(update.message)


# --- Final stage ---


# initializing services and queues

message_queue = []

mcu = ModuleControlUnit()

processor_thread = threading.Thread(target=queue_processor, args=[])
processor_thread.start()


# connecting to Telegram servers and listening for messages

TOKEN = readfile("config/token")
if not TOKEN:
    print("[CRIT] Token has not been defined, quitting")
    sys.exit(1)

# connect to Telegram servers
updater = Updater(TOKEN, use_context=True)
dispatcher = updater.dispatcher

# assign the handler for messages
dispatcher.add_handler(MessageHandler(Filters.text, message_handler))

# run the bot
updater.start_polling()
updater.idle()