From e06b92e4d975ebec9c2f924c00baf24fa2feb5ec Mon Sep 17 00:00:00 2001
From: SyberiaK <syberiakey@gmail.com>
Date: Fri, 19 Apr 2024 17:10:30 +0500
Subject: [PATCH] Formatting conversion (fails on 3+ styles applied to the same
 text chunk but whatever)

---
 plugins/incs2chat.py | 63 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 55 insertions(+), 8 deletions(-)

diff --git a/plugins/incs2chat.py b/plugins/incs2chat.py
index 4e30525..99c2613 100644
--- a/plugins/incs2chat.py
+++ b/plugins/incs2chat.py
@@ -4,7 +4,7 @@
 
 import requests
 from pyrogram import Client, filters
-from pyrogram.enums import ChatMembersFilter
+from pyrogram.enums import ChatMembersFilter, MessageEntityType
 from pyrogram.types import Message, MessageEntity
 
 # noinspection PyUnresolvedReferences
@@ -12,8 +12,8 @@
 import config
 
 
-def correct_message_entity(entities: list[MessageEntity] | None,
-                           original_text: str, new_text: str) -> list[MessageEntity] | None:
+def correct_message_entities(entities: list[MessageEntity] | None,
+                             original_text: str, new_text: str) -> list[MessageEntity] | None:
     """Correct message entities (a.k.a. Markdown formatting) for edited text."""
 
     if entities is None:
@@ -34,6 +34,52 @@ def correct_message_entity(entities: list[MessageEntity] | None,
     return entities
 
 
+def convert_message_to_markdown_text(message: Message) -> str:
+    """Convert Telegram formatting to Markdown (primarily for Discord)."""
+
+    entity_type_to_markdown = {  # only includes simple closing entities
+        MessageEntityType.BOLD:      '**',
+        MessageEntityType.ITALIC:    '*',
+        MessageEntityType.UNDERLINE: '__',
+        MessageEntityType.STRIKETHROUGH: '~~',
+        MessageEntityType.SPOILER: '||',
+        MessageEntityType.CODE: '`'
+    }
+
+    text = message.text or message.caption or ''
+
+    if message.entities is None:
+        return text
+
+    text = list(text)
+    text_shift = 0
+    for entity in message.entities:
+        # special cases first
+        if entity.type is MessageEntityType.TEXT_LINK:
+            text.insert(entity.offset + text_shift, '[')
+            text.insert(entity.offset + entity.length + text_shift + 1, f']({entity.url})')
+            text_shift += 2
+        if entity.type is MessageEntityType.PRE:
+            text.insert(entity.offset + text_shift, f'```{entity.language}\n')
+            text.insert(entity.offset + entity.length + text_shift + 1, f'\n```')
+            text_shift += 2
+        if entity.type is MessageEntityType.BLOCKQUOTE:
+            text.insert(entity.offset + text_shift, '> ')
+            text_shift += 1
+
+        symbol = entity_type_to_markdown.get(entity.type)
+        if symbol:
+            previous_symbol = text[entity.offset + text_shift - 2]
+            if previous_symbol in entity_type_to_markdown.values():  # todo: still fails on 3+ styles in the same chunk
+                text.insert(entity.offset + text_shift - 1, symbol)
+                text.insert(entity.offset + entity.length + text_shift, symbol)
+            else:
+                text.insert(entity.offset + text_shift, symbol)
+                text.insert(entity.offset + entity.length + text_shift + 1, symbol)
+            text_shift += 2
+    return ''.join(text)
+
+
 def translate_text(text: str, source_lang: str = 'RU', target_lang: str = 'EN'):
     headers = {'Authorization': f'DeepL-Auth-Key {config.DEEPL_TOKEN}', 'Content-Type': 'application/json'}
     data = {'text': [text], 'source_lang': source_lang, 'target_lang': target_lang}
@@ -47,7 +93,7 @@ def translate_text(text: str, source_lang: str = 'RU', target_lang: str = 'EN'):
     logging.error(f'{r.status_code=}, {r.reason=}')
 
 
-def post_to_discord_webhook(url: str, text: str):
+def post_to_discord_webhook(url: str, text: str):  # todo: attachments support?
     headers = {'Content-Type': 'application/json'}
     payload = {'content': text}
     r = requests.post(url, json=payload, headers=headers)
@@ -123,7 +169,7 @@ async def echo(client: Client, message: Message):
 
     if message.text:
         text = message.text.removeprefix('/echo').strip()
-        entities = correct_message_entity(message.entities, message.text, text)
+        entities = correct_message_entities(message.entities, message.text, text)
 
         if not text:
             msg = await message.reply('Пустой текст.', quote=False)
@@ -134,7 +180,7 @@ async def echo(client: Client, message: Message):
         return await reply_to.reply(text, entities=entities, quote=should_reply, disable_web_page_preview=True)
 
     caption = message.caption.removeprefix('/echo').strip()
-    entities = correct_message_entity(message.entities, message.caption, caption)
+    entities = correct_message_entities(message.entities, message.caption, caption)
 
     if message.animation:
         animation = message.animation.file_id
@@ -163,8 +209,9 @@ async def echo(client: Client, message: Message):
 
 @Client.on_message(filters.channel & filters.chat(config.INCS2CHANNEL))
 async def forward_to_discord(_, message: Message):
-    text = message.text if message.text is not None else message.caption     # todo: attachments support?
-    
+    text = convert_message_to_markdown_text(message)
+    logging.info(text)
+
     if text:
         post_to_discord_webhook(config.DS_WEBHOOK_URL, text)
         post_to_discord_webhook(config.DS_WEBHOOK_URL_EN, translate_text(text, 'RU', 'EN'))