work-in-progress: when upload a text file attachment, ask for permission to auto-upload to pastebin.

Also DMs the delete URL to the user. This code will very likely be moved elsewhere before/if it is merged.

2 files changed, 92 insertions, 2 deletions

diff --git a/bot/exts/filtering/_filter_lists/extension.py b/bot/exts/filtering/_filter_lists/extension.py
index d656bc6d2..3e7fa8e75 100644
--- a/bot/exts/filtering/_filter_lists/extension.py
+++ b/bot/exts/filtering/_filter_lists/extension.py
@@ -1,10 +1,18 @@
 from __future__ import annotations
 
+import logging
+import re
 import typing
 from os.path import splitext
 
+import aiohttp
+import discord
+from discord.ext import commands
+from pydis_core.utils import paste_service
+
 import bot
-from bot.constants import Channels
+from bot.bot import Bot
+from bot.constants import Channels, Emojis
 from bot.exts.filtering._filter_context import Event, FilterContext
 from bot.exts.filtering._filter_lists.filter_list import FilterList, ListType
 from bot.exts.filtering._filters.extension import ExtensionFilter
@@ -20,7 +28,7 @@ PY_EMBED_DESCRIPTION = (
     f"please use a code-pasting service such as {PASTE_URL}"
 )
 
-TXT_LIKE_FILES = {".txt", ".csv", ".json"}
+TXT_LIKE_FILES = {".txt", ".csv", ".json", ".py"}
 TXT_EMBED_DESCRIPTION = (
     "You either uploaded a `{blocked_extension}` file or entered a message that was too long. "
     f"Please use our [paste bin]({PASTE_URL}) instead."
@@ -32,6 +40,9 @@ DISALLOWED_EMBED_DESCRIPTION = (
     "Feel free to ask in {meta_channel_mention} if you think this is a mistake."
 )
 
+PASTEBIN_UPLOAD_EMOJI = Emojis.check_mark
+DELETE_PASTE_EMOJI = Emojis.trashcan
+
 
 class ExtensionsList(FilterList[ExtensionFilter]):
     """
@@ -116,3 +127,80 @@ class ExtensionsList(FilterList[ExtensionFilter]):
         ctx.blocked_exts |= set(not_allowed)
         actions = self[ListType.ALLOW].defaults.actions if ctx.event != Event.SNEKBOX else None
         return actions, [f"`{ext}`" if ext else "`No Extension`" for ext in not_allowed], {ListType.ALLOW: triggered}
+
+
+class EmbedFileHandler(commands.Cog):
+
+    def __init__(self, bot: Bot):
+        self.bot = bot
+
+    @staticmethod
+    async def _convert_attachment(attachment: discord.Attachment) -> paste_service.PasteFile:
+        encoding = re.search(r"charset=(\S+)", attachment.content_type).group(1)
+        file_content = (await attachment.read()).decode(encoding)
+        return paste_service.PasteFile(content=file_content, name=attachment.filename)
+
+    @commands.Cog.listener()
+    async def on_message(self, message: discord.Message) -> None:
+        # Check if the message contains an embedded file and is not sent by a bot
+        if message.author.bot or not message.attachments:
+            return
+
+        bot_reply = await message.reply(f"React with {PASTEBIN_UPLOAD_EMOJI} to upload your file to our paste bin")
+        await bot_reply.add_reaction(PASTEBIN_UPLOAD_EMOJI)
+
+        def wait_for_upload_permission(reaction: discord.Reaction, user: discord.User) -> bool:
+            return (
+                reaction.message.id == bot_reply.id
+                and str(reaction.emoji) == PASTEBIN_UPLOAD_EMOJI
+                and user == message.author
+            )
+
+        try:
+            # Wait for the reaction with a timeout of 60 seconds
+            await self.bot.wait_for("reaction_add", timeout=60.0, check=wait_for_upload_permission)
+        except TimeoutError:
+            await bot_reply.edit(content=f"~~{bot_reply.content}~~")
+            await bot_reply.clear_reactions()
+            return
+
+        logging.info({f.filename: f.content_type for f in message.attachments})
+
+        files = [
+            await self._convert_attachment(f)
+            for f in message.attachments
+            if f.content_type.startswith("text")
+        ]
+
+        try:
+            async with aiohttp.ClientSession() as session:
+                paste_response = await paste_service.send_to_paste_service(files=files, http_session=session)
+        except (paste_service.PasteTooLongError, ValueError):
+            # paste is too long
+            await bot_reply.edit(content="Your paste is too long, and couldn't be uploaded.")
+            return
+        except paste_service.PasteUploadError:
+            await bot_reply.edit(content="There was an error uploading your paste.")
+            return
+
+        # The angle brackets around the remove link are required to stop Discord from visiting the URL to produce a
+        # preview, thereby deleting the paste
+        await message.author.send(content=f"[Click here](<{paste_response.removal}>) to delete your recent paste.")
+
+        await bot_reply.edit(content=f"[Click here]({paste_response.link}) to see this code in our pastebin.")
+        await bot_reply.clear_reactions()
+        await bot_reply.add_reaction(DELETE_PASTE_EMOJI)
+
+        def wait_for_delete_reaction(reaction: discord.Reaction, user: discord.User) -> bool:
+            return (
+                reaction.message.id == bot_reply.id
+                and str(reaction.emoji) == DELETE_PASTE_EMOJI
+                and user == message.author
+            )
+
+        try:
+            await self.bot.wait_for("reaction_add", timeout=60.0 * 10, check=wait_for_delete_reaction)
+            await paste_response.delete()
+            await bot_reply.delete()
+        except TimeoutError:
+            pass
diff --git a/bot/exts/filtering/filtering.py b/bot/exts/filtering/filtering.py
index 844f2942e..929eb064c 100644
--- a/bot/exts/filtering/filtering.py
+++ b/bot/exts/filtering/filtering.py
@@ -28,6 +28,7 @@ from bot.constants import BaseURLs, Channels, Guild, MODERATION_ROLES, Roles
 from bot.exts.backend.branding._repository import HEADERS, PARAMS
 from bot.exts.filtering._filter_context import Event, FilterContext
 from bot.exts.filtering._filter_lists import FilterList, ListType, ListTypeConverter, filter_list_types
+from bot.exts.filtering._filter_lists.extension import EmbedFileHandler
 from bot.exts.filtering._filter_lists.filter_list import AtomicList
 from bot.exts.filtering._filters.filter import Filter, UniqueFilter
 from bot.exts.filtering._settings import ActionSettings
@@ -1492,3 +1493,4 @@ class Filtering(Cog):
 async def setup(bot: Bot) -> None:
     """Load the Filtering cog."""
     await bot.add_cog(Filtering(bot))
+    await bot.add_cog(EmbedFileHandler(bot))