extract links, delete incoming msg, add sender to reply

bot/bot.py

@@ -5,6 +5,10 @@ from secret import TOKEN
 import textbook
 import re
 from urllib.parse import urlparse, urlunparse
+from msgprocessor import (
+    TrackerRemovalMsgProcessor,
+    TrackerRemovalProcessorMessage
+)
 import random
 
 HAS_LINK_RE = r'(https?:\/\/[^\s]+|www\.[^\s]+)'
@@ -45,10 +49,31 @@ async def start(msg: Message):
 
 @bot.message_handler(func=lambda message: True)
 async def got_message(msg: Message):
-    if re.match(string=msg.text, pattern=HAS_LINK_RE):
-        fixed_reply = process_text(msg.text)
-        if fixed_reply:
-            await bot.reply_to(msg, fixed_reply)
+    # god i love nones as fuck
+    if msg.text is None:
+        return
+    if msg.from_user is None:
+        return
+    if msg.from_user.username is None:
+        return
+
+    tracker_removal_result = TrackerRemovalMsgProcessor(
+        TrackerRemovalProcessorMessage(
+            fromUsername=msg.from_user.username,
+            text=msg.text
+        )
+    ).process()
+
+    if not tracker_removal_result.needsToReply:
+        return
+
+    try:
+        await bot.delete_message(msg.chat.id, msg.id, 5)
+    except Exception as e:
+        print(e) # todo: логгер
+        return
+
+    await bot.send_message(msg.chat.id, tracker_removal_result.text)
 
 
 async def main():

bot/exception.py

@@ -0,0 +1,9 @@
+class UrlRemoverNotImplementedException(Exception):
+    def __init__(self, domain: str):
+        self.__base_message = "Url remover for domain not implemented"
+        self.domain = domain
+        super().__init__(self.__base_message)
+
+    
+    def __str__(self):
+        return f'{self.__base_message}: {self.domain}'

bot/msgprocessor.py

@@ -0,0 +1,118 @@
+from typing import Callable
+from dataclasses import dataclass
+from exception import UrlRemoverNotImplementedException
+from urllib.parse import urlparse, parse_qs, urlencode, urlunparse
+from utils import find_all_string_entries
+
+
+@dataclass(init=True)
+class TrackerRemovalProcessorMessage:
+    fromUsername: str
+    text: str
+
+
+@dataclass(frozen=True, init=True)
+class TrackerRemovalResult:
+    needsToReply: bool
+    text: str
+
+
+class TrackerRemovalMsgProcessor:
+    def __init__(self, msg: TrackerRemovalProcessorMessage):
+        self.__msg = msg
+
+    def process(self) -> TrackerRemovalResult:
+        if not self.__remove_trackers_from_msg_urls():
+            return TrackerRemovalResult(needsToReply=False, text="") # дальнейшие трансформации смысла не имеют
+        self.__emplace_sender_into_msg_text()
+        return TrackerRemovalResult(needsToReply=True, text=self.__msg.text) # сообщение было изменено, нужно ответ отослать
+
+    def __remove_trackers_from_msg_urls(self) -> bool:
+        trackers_extracted = False
+        # todo: вообще мы работаем с http и это юзкейс обскьюрный
+        # но ссылка может быть и без указания схемы, телега может распарсить
+        # просто строку через точки и в конце какой то домен верхнего уровня как ссылку
+        SCHEME = "http://"
+        links_entries = find_all_string_entries(self.__msg.text, SCHEME)
+
+        # разобьем строку на просто текст и ссылки
+        # с in-place преобразованием на норм ссылки
+        splitted_by_urls: list[str] = []
+        before_link_idx = 0
+        for link_entry in links_entries:
+            # будем искать либо конец строки либо пробел
+            space_index = len(self.__msg.text)
+            try:
+                space_index = self.__msg.text.index(" ", link_entry)
+            except ValueError:
+                pass
+
+            if link_entry - before_link_idx > 0:
+                splitted_by_urls.append(self.__msg.text[before_link_idx:link_entry])
+
+            url = self.__msg.text[link_entry:space_index]
+            removed_trackers_url = self.__remove_tracker(url)
+            if url != removed_trackers_url:
+                trackers_extracted = True
+            splitted_by_urls.append(removed_trackers_url)
+
+        if len(self.__msg.text) - before_link_idx > 0:
+            splitted_by_urls.append(self.__msg.text[before_link_idx:])
+
+        self.__msg.text = "".join(splitted_by_urls)
+        return trackers_extracted
+
+    @staticmethod
+    def __remove_tracker(url: str) -> str:
+        parsed_url = urlparse(url)
+        if parsed_url.hostname is None:
+            return url
+        hostname = str(parsed_url.hostname)
+        try:
+            return TrackerRemoverFactory.make_remover(hostname)(url)
+        except UrlRemoverNotImplementedException:
+            return url
+
+    def __emplace_sender_into_msg_text(self):
+        self.__msg.text = f'Message from {self.__msg.fromUsername}:\n\n{self.__msg.text}'
+
+
+class TrackerRemoverFactory:
+    TrackerRemover = Callable[[str], str]
+
+    @staticmethod
+    def make_remover(domain: str) -> TrackerRemover:
+        @dataclass(frozen=True, init=True)
+        class RemoverIdentifyer:
+            domains: list[str]
+            remover: TrackerRemoverFactory.TrackerRemover
+
+        removers_by_domain = [
+            RemoverIdentifyer(
+                domains=["youtube.com", "youtu.be"],
+                remover=TrackerRemoverFactory.remove_yt_trackers,
+            )
+        ]
+        remover_one = [
+            r 
+            for r in removers_by_domain
+            if len([d for d in r.domains if d.endswith(domain)]) != 0
+        ]
+        if len(remover_one) == 0:
+            raise UrlRemoverNotImplementedException(domain)
+        return remover_one[0].remover
+
+    @staticmethod
+    def remove_yt_trackers(url: str) -> str:
+        # todo: подумать как обобщить, мб билдер стратегии поиска трекера
+        # но эт сильно на потом
+        QUERY_PARAMS_TRACKER = "si"
+        parsed_url = urlparse(url)
+        query_params = parse_qs(parsed_url.query)
+        if QUERY_PARAMS_TRACKER in query_params:
+            del query_params[QUERY_PARAMS_TRACKER]
+        return urlunparse(
+            parsed_url._replace(
+                query=urlencode(query_params, doseq=True)
+            )
+        )

bot/utils.py

@@ -0,0 +1,6 @@
+def find_all_string_entries(s: str, sub: str) -> list[int]:
+    result = []
+    for i in range(len(s)-len(sub)+1):
+        if s[i:i+len(sub)] == sub: # в питоне точно сравнение строк лексикографически? (забыл)
+            result.append(i)
+    return result