upub/src/activitypub/well_known.rs

use axum::{extract::{Path, Query, State}, http::StatusCode, response::{IntoResponse, Response}, Json};
use jrd::{JsonResourceDescriptor, JsonResourceDescriptorLink};
use sea_orm::{EntityTrait, PaginatorTrait};

use crate::{model, server::Context};

#[derive(serde::Serialize)]
pub struct NodeInfoDiscovery {
	pub links: Vec<NodeInfoDiscoveryRel>,
}

#[derive(serde::Serialize)]
pub struct NodeInfoDiscoveryRel {
	pub rel: String,
	pub href: String,
}

pub async fn nodeinfo_discovery(State(ctx): State<Context>) -> Json<NodeInfoDiscovery> {
	Json(NodeInfoDiscovery {
		links: vec![
			NodeInfoDiscoveryRel {
				rel: "http://nodeinfo.diaspora.software/ns/schema/2.0".into(),
				href: format!("{}/nodeinfo/2.0.json", ctx.base()),
			},
			NodeInfoDiscoveryRel {
				rel: "http://nodeinfo.diaspora.software/ns/schema/2.1".into(),
				href: format!("{}/nodeinfo/2.1.json", ctx.base()),
			},
		],
	})
}

// TODO either vendor or fork nodeinfo-rs because it still represents "repository" and "homepage"
// even if None! technically leads to invalid nodeinfo 2.0
pub async fn nodeinfo(State(ctx): State<Context>, Path(version): Path<String>) -> Result<Json<nodeinfo::NodeInfoOwned>, StatusCode> {
	// TODO it's unsustainable to count these every time, especially comments since it's a complex
	// filter! keep these numbers caches somewhere, maybe db, so that we can just look them up
	let total_users = model::user::Entity::find().count(ctx.db()).await.ok();
	let total_posts = None;
	let total_comments = None; 
	let (software, version) = match version.as_str() {
		"2.0.json" => (
			nodeinfo::types::Software {
				name: "μpub".to_string(),
				version: Some(env!("CARGO_PKG_VERSION").into()),
				repository: None,
				homepage: None,
			},
			"2.0".to_string()
		),
		"2.1.json" => (
			nodeinfo::types::Software {
				name: "μpub".to_string(),
				version: Some(env!("CARGO_PKG_VERSION").into()),
				repository: Some("https://git.alemi.dev/upub.git/".into()),
				homepage: None,
			},
			"2.1".to_string()
		),
		_ => return Err(StatusCode::NOT_IMPLEMENTED),
	};
	Ok(Json(
		nodeinfo::NodeInfoOwned {
			version,
			software,
			open_registrations: false,
			protocols: vec!["activitypub".into()],
			services: nodeinfo::types::Services {
				inbound: vec![],
				outbound: vec![],
			},
			usage: nodeinfo::types::Usage {
				local_posts: total_posts,
				local_comments: total_comments,
				users: Some(nodeinfo::types::Users {
					active_month: None,
					active_halfyear: None,
					total: total_users.map(|x| x as i64),
				}),
			},
			metadata: serde_json::Map::default(),
		}
	))
}


#[derive(Debug, serde::Deserialize)]
pub struct WebfingerQuery {
	pub resource: String,
}

pub struct JsonRD<T>(pub T);
impl<T: serde::Serialize> IntoResponse for JsonRD<T> {
	fn into_response(self) -> Response {
		([("Content-Type", "application/jrd+json")], Json(self.0)).into_response()
	}
}

pub async fn webfinger(State(ctx): State<Context>, Query(query): Query<WebfingerQuery>) -> Result<JsonRD<JsonResourceDescriptor>, StatusCode> {
	if let Some((user, domain)) = query
		.resource
		.replace("acct:", "")
		.split_once('@')
	{
		let uid = ctx.uid(user.to_string());
		match model::user::Entity::find_by_id(uid)
			.one(ctx.db())
			.await
		{
			Ok(Some(x)) => Ok(JsonRD(JsonResourceDescriptor {
				subject: format!("acct:{user}@{domain}"),
				aliases: vec![x.id.clone()],
				links: vec![
					JsonResourceDescriptorLink {
						rel: "self".to_string(),
						link_type: Some("application/ld+json".to_string()),
						href: Some(x.id),
						properties: jrd::Map::default(),
						titles: jrd::Map::default(),
					},
				],
				expires: None,
				properties: jrd::Map::default(),
			})),
			Ok(None) => Err(StatusCode::NOT_FOUND),
			Err(e) => {
				tracing::error!("error executing webfinger query: {e}");
				Err(StatusCode::INTERNAL_SERVER_ERROR)
			},
		}
	} else {
		Err(StatusCode::UNPROCESSABLE_ENTITY)
	}
}

// i don't even want to bother with XML, im just returning a formatted xml string
pub async fn host_meta(State(ctx): State<Context>) -> Response {
	(
		[("Content-Type", "application/xrd+xml")],
		format!(r#"<?xml version="1.0" encoding="UTF-8"?>
			<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
				<Link type="application/xrd+xml" template="{}/.well-known/webfinger?resource={{uri}}" rel="lrdd" />
			</XRD>"#,
			ctx.base())
	).into_response()
}