Add support for replies to help snippets

[Saber0324]

PR for issue #3537

This implementation makes the bot reply to the same message that the caller replies, and if the command invoke isn't a reply, the bot maintains its current behavior, sending the snippet without replying to the caller.
If the caller replies to himself, the bot also maintains the no-reply behavior.

It is currently implemented for (all aliases of):

• !learn
• !kind
• !pep
• !src
• !code
• !res
• !gif

Due to the use of LinePaginator.paginate in !rule command, I wasn't able to implement it for all of its variants, so I left it untouched for consistency. (I'll open an issue about it if the PR gets merged)

[jb3]

For various reasons we probably don't want to add this functionality to !rule, so I wouldn't worry about that limitation.

It is not users responsibility to moderate others and the rule command serves as a reference rather than a tool for non-staff members.

[ShaharNaveh]

I approve if it's worth anything

Invalidated by push of d50401d

Invalidated by push of a94def3

[Sacul0457]

sorry if wasn't very clear,
it should look something like this

Suggested change

	async def get_reference_message(ctx: Context) -> Message | None:
	"""Return a message reference if the reference exists and it does not refer to the author of the message."""
	if ctx.message.reference is None:
	return None
	try:
	referenced_message = ctx.message.reference.resolved
	except (discord.Forbidden, discord.NotFound):
	return None
	else:
	if referenced_message is None or isinstance(referenced_message, DeletedReferencedMessage):
	return None
	if referenced_message.author == ctx.author:
	return None
	return referenced_message
	async def get_reference_message(ctx: Context) -> Message | None:
	"""Return a message reference if the reference exists and it does not refer to the author of the message."""
	if ctx.message.reference is None:
	return None
	try:
	referenced_message = .resolved or .cached_message or await fetch_message(...)
	except (discord.Forbidden, discord.NotFound):
	return None
	else:
	if isinstance(referenced_message, DeletedReferencedMessage):
	return None
	if referenced_message.author == ctx.author:
	return None
	return referenced_message

NotFound and Forbidden won't ever be raised unless an API call is made.
Basically the idea is to check the data in resolved, if empty, check cached_message, if also empty finally make an api call.

[Sacul0457]

Yes this looks gud now, just one minor nit: referenced_message can never be None here as if resolved or cached_message is None, we will fetch using the API, which will raise NotFound etc. if the message can't be fetched.

[onerandomusername]

This can fail if the referenced message is deleted between the fetch and send.

This is undesirable behavior since the bot will just fail to respond in that case. The command has been invoked, a reply being deleted shouldn't cause the bot to not reply either.

One of two options:

• You'll need to construct a new reference with fail_if_not_exists set to False and provide that to .send()
• try, except a failure, try again without the reference.

[Saber0324]

    reference = None
    if message_reference := await get_reference_message(ctx):
        reference = message_reference
    return await ctx.send(embed=embed, reference=reference)

Would this approach work? I tested the None case by commenting the line that sets the message_reference and it's sent as a normal message. This is the simplest solution I came across.

Actually, looking at how you reconstruct references, the first approach you mentioned is better, mine would fail anyways since an exception is raised.

    if message_reference := await get_reference_message(ctx):
        reference = message_reference.to_reference(fail_if_not_exists=False)
        return await ctx.send(embed=embed, reference=reference)
    return await ctx.send(embed=embed)

I don't like the duplication, but this avoids what you mentioned.

[Saber0324]

I confirmed that this version works, is there anything else I could upgrade? ^^