lemmy/crates/apub/src/objects/mod.rs

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use crate::{
check_is_apub_id_valid,
fetcher::{community::get_or_fetch_and_upsert_community, user::get_or_fetch_and_upsert_user},
inbox::community_inbox::check_community_or_site_ban,
};
use activitystreams::{
base::{AsBase, BaseExt, ExtendsExt},
markers::Base,
mime::{FromStrError, Mime},
object::{ApObjectExt, Object, ObjectExt, Tombstone, TombstoneExt},
};
use anyhow::{anyhow, Context};
use chrono::NaiveDateTime;
use diesel::result::Error::NotFound;
use lemmy_api_structs::blocking;
use lemmy_db_queries::{ApubObject, Crud, DbPool};
use lemmy_db_schema::{source::community::Community, DbUrl};
use lemmy_utils::{
location_info,
settings::structs::Settings,
utils::{convert_datetime, markdown_to_html},
LemmyError,
};
use lemmy_websocket::LemmyContext;
use url::Url;
pub(crate) mod comment;
pub(crate) mod community;
pub(crate) mod post;
pub(crate) mod private_message;
pub(crate) mod user;
/// Trait for converting an object or actor into the respective ActivityPub type.
#[async_trait::async_trait(?Send)]
pub(crate) trait ToApub {
type ApubType;
async fn to_apub(&self, pool: &DbPool) -> Result<Self::ApubType, LemmyError>;
fn to_tombstone(&self) -> Result<Tombstone, LemmyError>;
}
#[async_trait::async_trait(?Send)]
pub(crate) trait FromApub {
type ApubType;
/// Converts an object from ActivityPub type to Lemmy internal type.
///
/// * `apub` The object to read from
/// * `context` LemmyContext which holds DB pool, HTTP client etc
/// * `expected_domain` Domain where the object was received from. None in case of mod action.
async fn from_apub(
apub: &Self::ApubType,
context: &LemmyContext,
expected_domain: Option<Url>,
request_counter: &mut i32,
) -> Result<Self, LemmyError>
where
Self: Sized;
}
#[async_trait::async_trait(?Send)]
pub(in crate::objects) trait FromApubToForm<ApubType> {
async fn from_apub(
apub: &ApubType,
context: &LemmyContext,
expected_domain: Option<Url>,
request_counter: &mut i32,
) -> Result<Self, LemmyError>
where
Self: Sized;
}
/// Updated is actually the deletion time
fn create_tombstone<T>(
deleted: bool,
object_id: Url,
updated: Option<NaiveDateTime>,
former_type: T,
) -> Result<Tombstone, LemmyError>
where
T: ToString,
{
if deleted {
if let Some(updated) = updated {
let mut tombstone = Tombstone::new();
tombstone.set_id(object_id);
tombstone.set_former_type(former_type.to_string());
tombstone.set_deleted(convert_datetime(updated));
Ok(tombstone)
} else {
Err(anyhow!("Cant convert to tombstone because updated time was None.").into())
}
} else {
Err(anyhow!("Cant convert object to tombstone if it wasnt deleted").into())
}
}
pub(in crate::objects) fn check_object_domain<T, Kind>(
apub: &T,
expected_domain: Url,
) -> Result<DbUrl, LemmyError>
where
T: Base + AsBase<Kind>,
{
let domain = expected_domain.domain().context(location_info!())?;
let object_id = apub.id(domain)?.context(location_info!())?;
check_is_apub_id_valid(object_id)?;
Ok(object_id.to_owned().into())
}
pub(in crate::objects) fn set_content_and_source<T, Kind1, Kind2>(
object: &mut T,
markdown_text: &str,
) -> Result<(), LemmyError>
where
T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
{
let mut source = Object::<()>::new_none_type();
source
.set_content(markdown_text)
.set_media_type(mime_markdown()?);
object.set_source(source.into_any_base()?);
object.set_content(markdown_to_html(markdown_text));
object.set_media_type(mime_html()?);
Ok(())
}
pub(in crate::objects) fn get_source_markdown_value<T, Kind1, Kind2>(
object: &T,
) -> Result<Option<String>, LemmyError>
where
T: ApObjectExt<Kind1> + ObjectExt<Kind2> + AsBase<Kind2>,
{
let content = object
.content()
.map(|s| s.as_single_xsd_string().map(|s2| s2.to_string()))
.flatten();
if content.is_some() {
let source = object.source().context(location_info!())?;
let source = Object::<()>::from_any_base(source.to_owned())?.context(location_info!())?;
check_is_markdown(source.media_type())?;
let source_content = source
.content()
.map(|s| s.as_single_xsd_string().map(|s2| s2.to_string()))
.flatten()
.context(location_info!())?;
return Ok(Some(source_content));
}
Ok(None)
}
fn mime_markdown() -> Result<Mime, FromStrError> {
"text/markdown".parse()
}
fn mime_html() -> Result<Mime, FromStrError> {
"text/html".parse()
}
pub(in crate::objects) fn check_is_markdown(mime: Option<&Mime>) -> Result<(), LemmyError> {
let mime = mime.context(location_info!())?;
if !mime.eq(&mime_markdown()?) {
Err(LemmyError::from(anyhow!(
"Lemmy only supports markdown content"
)))
} else {
Ok(())
}
}
/// Converts an ActivityPub object (eg `Note`) to a database object (eg `Comment`). If an object
/// with the same ActivityPub ID already exists in the database, it is returned directly. Otherwise
/// the apub object is parsed, inserted and returned.
pub(in crate::objects) async fn get_object_from_apub<From, Kind, To, ToForm>(
from: &From,
context: &LemmyContext,
expected_domain: Option<Url>,
request_counter: &mut i32,
) -> Result<To, LemmyError>
where
From: BaseExt<Kind>,
To: ApubObject<ToForm> + Crud<ToForm> + Send + 'static,
ToForm: FromApubToForm<From> + Send + 'static,
{
let object_id = from.id_unchecked().context(location_info!())?.to_owned();
let domain = object_id.domain().context(location_info!())?;
// if its a local object, return it directly from the database
if Settings::get().hostname() == domain {
let object = blocking(context.pool(), move |conn| {
To::read_from_apub_id(conn, &object_id.into())
})
.await??;
Ok(object)
}
// otherwise parse and insert, assuring that it comes from the right domain
else {
let to_form = ToForm::from_apub(&from, context, expected_domain, request_counter).await?;
let to = blocking(context.pool(), move |conn| To::upsert(conn, &to_form)).await??;
Ok(to)
}
}
pub(in crate::objects) async fn check_object_for_community_or_site_ban<T, Kind>(
object: &T,
community_id: i32,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<(), LemmyError>
where
T: ObjectExt<Kind>,
{
let user_id = object
.attributed_to()
.context(location_info!())?
.as_single_xsd_any_uri()
.context(location_info!())?;
let user = get_or_fetch_and_upsert_user(user_id, context, request_counter).await?;
check_community_or_site_ban(&user, community_id, context.pool()).await
}
pub(in crate::objects) async fn get_to_community<T, Kind>(
object: &T,
context: &LemmyContext,
request_counter: &mut i32,
) -> Result<Community, LemmyError>
where
T: ObjectExt<Kind>,
{
let community_ids = object
.to()
.context(location_info!())?
.as_many()
.context(location_info!())?
.iter()
.map(|a| a.as_xsd_any_uri().context(location_info!()))
.collect::<Result<Vec<&Url>, anyhow::Error>>()?;
for cid in community_ids {
let community = get_or_fetch_and_upsert_community(&cid, context, request_counter).await;
if community.is_ok() {
return community;
}
}
Err(NotFound.into())
}