Undo a revert

2 files changed, 162 insertions, 1 deletions

diff --git a/bot/exts/filtering/filtering.py b/bot/exts/filtering/filtering.py
index 844f2942e..377cff015 100644
--- a/bot/exts/filtering/filtering.py
+++ b/bot/exts/filtering/filtering.py
@@ -66,6 +66,14 @@ OFFENSIVE_MSG_DELETE_TIME = datetime.timedelta(days=7)
 WEEKLY_REPORT_ISO_DAY = 3  # 1=Monday, 7=Sunday
 
 
+async def _extract_text_file_content(att: discord.Attachment) -> str:
+    """Extract up to the first 30 lines and first 2000 characters (whichever is shorter) of an attachment."""
+    file_encoding = re.search(r"charset=(\S+)", att.content_type).group(1)
+    file_lines: list[str] = (await att.read()).decode(encoding=file_encoding).splitlines()
+    first_n_lines = "\n".join(file_lines[:30])[:2_000]
+    return f"{att.filename}: {first_n_lines}"
+
+
 class Filtering(Cog):
     """Filtering and alerting for content posted on the server."""
 
@@ -80,7 +88,7 @@ class Filtering(Cog):
     def __init__(self, bot: Bot):
         self.bot = bot
         self.filter_lists: dict[str, FilterList] = {}
-        self._subscriptions: defaultdict[Event, list[FilterList]] = defaultdict(list)
+        self._subscriptions = defaultdict[Event, list[FilterList]](list)
         self.delete_scheduler = scheduling.Scheduler(self.__class__.__name__)
         self.webhook: discord.Webhook | None = None
 
@@ -223,6 +231,15 @@ class Filtering(Cog):
         self.message_cache.append(msg)
 
         ctx = FilterContext.from_message(Event.MESSAGE, msg, None, self.message_cache)
+
+        text_contents = [
+            await _extract_text_file_content(a)
+            for a in msg.attachments if "charset" in a.content_type
+        ]
+        if text_contents:
+            attachment_content = "\n\n".join(text_contents)
+            ctx = ctx.replace(content=f"{ctx.content}\n\n{attachment_content}")
+
         result_actions, list_messages, triggers = await self._resolve_action(ctx)
         self.message_cache.update(msg, metadata=triggers)
         if result_actions:
diff --git a/bot/exts/utils/attachment_pastebin_uploader.py b/bot/exts/utils/attachment_pastebin_uploader.py
new file mode 100644
index 000000000..805abd238
--- /dev/null
+++ b/bot/exts/utils/attachment_pastebin_uploader.py
@@ -0,0 +1,144 @@
+from __future__ import annotations
+
+import re
+
+import aiohttp
+import discord
+from discord.ext import commands
+from pydis_core.utils import paste_service
+
+from bot.bot import Bot
+from bot.constants import Emojis
+from bot.log import get_logger
+
+log = get_logger(__name__)
+
+PASTEBIN_UPLOAD_EMOJI = Emojis.check_mark
+DELETE_PASTE_EMOJI = Emojis.trashcan
+
+
+class EmbedFileHandler(commands.Cog):
+    """
+    Handles automatic uploading of attachments to the paste bin.
+
+    Whenever a user uploads one or more attachments that is text-based (py, txt, csv, etc.), this cog offers to upload
+    all the attachments to the paste bin automatically. The steps are as follows:
+    - The bot replies to the message containing the attachments, asking the user to react with a checkmark to consent
+        to having the content uploaded.
+    - If consent is given, the bot uploads the contents and edits its own message to contain the link.
+    - The bot DMs the user the delete link for the paste.
+    - The bot waits for the user to react with a trashcan emoji, in which case the bot deletes the paste and its own
+        message.
+    """
+
+    def __init__(self, bot: Bot):
+        self.bot = bot
+        self.pending_messages = set[int]()
+
+    @staticmethod
+    async def _convert_attachment(attachment: discord.Attachment) -> paste_service.PasteFile:
+        """Converts an attachment to a PasteFile, according to the attachment's file encoding."""
+        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_delete(self, message: discord.Message) -> None:
+        """Allows us to know which messages with attachments have been deleted."""
+        self.pending_messages.discard(message.id)
+
+    @commands.Cog.listener()
+    async def on_message(self, message: discord.Message) -> None:
+        """Listens for messages containing attachments and offers to upload them to the pastebin."""
+        # Check if the message contains an embedded file and is not sent by a bot.
+        if message.author.bot or not any(a.content_type.startswith("text") for a in message.attachments):
+            return
+
+        log.trace(f"Offering to upload attachments for {message.author} in {message.channel}, message {message.id}")
+        self.pending_messages.add(message.id)
+
+        # Offer to upload the attachments and wait for the user's reaction.
+        bot_reply = await message.reply(
+            f"Please react with {PASTEBIN_UPLOAD_EMOJI} to upload your file(s) to our "
+            f"[paste bin](<https://paste.pythondiscord.com/>), which is more accessible for some users."
+        )
+        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:
+            # The user does not grant permission before the timeout. Exit early.
+            log.trace(f"{message.author} didn't give permission to upload {message.id} content; aborting.")
+            await bot_reply.edit(content=f"~~{bot_reply.content}~~")
+            await bot_reply.clear_reactions()
+
+        if message.id not in self.pending_messages:
+            log.trace(f"{message.author}'s message was deleted before the attachments could be uploaded; aborting.")
+            await bot_reply.delete()
+            return
+
+        # In either case, we do not want the message ID in pending_messages anymore.
+        self.pending_messages.discard(message.id)
+
+        # Extract the attachments.
+        files = [
+            await self._convert_attachment(f)
+            for f in message.attachments
+            if "charset" in f.content_type
+        ]
+
+        # Upload the files to the paste bin, exiting early if there's an error.
+        log.trace(f"Attempting to upload {len(files)} file(s) to pastebin.")
+        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):
+            log.trace(f"{message.author}'s attachments were too long.")
+            await bot_reply.edit(content="Your paste is too long, and couldn't be uploaded.")
+            return
+        except paste_service.PasteUploadError:
+            log.trace(f"Unexpected error uploading {message.author}'s attachments.")
+            await bot_reply.edit(content="There was an error uploading your paste.")
+            return
+
+        # Send the user a DM with the delete link for the paste.
+        # 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.")
+
+        # Edit the bot message to contain the link to the 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)
+
+        # Wait for the user to react with a trash can, which they can use to delete the paste.
+
+        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:
+            log.trace(f"Offering to delete {message.author}'s attachments in {message.channel}, message {message.id}")
+            await self.bot.wait_for("reaction_add", timeout=60.0 * 10, check=wait_for_delete_reaction)
+            # Delete the paste by visiting the removal URL.
+            async with aiohttp.ClientSession() as session:
+                await session.get(paste_response.removal)
+            await bot_reply.delete()
+        except TimeoutError:
+            log.trace(f"Offer to delete {message.author}'s attachments timed out.")
+
+
+async def setup(bot: Bot) -> None:
+    """Load the EmbedFileHandler cog."""
+    await bot.add_cog(EmbedFileHandler(bot))