Create webfinger crate' (#5)

Reviewed-on: #5

.gitignore

@@ -15,3 +15,6 @@ Cargo.lock
 
 # Environment
 .env.local
+
+# IntelliJ IDEA thing, mostly broken versioning
+.idea/misc.xml

.idea/acrate.iml

@@ -9,6 +9,7 @@
       <sourceFolder url="file://$MODULE_DIR$/acrate-inbox/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/acrate-nodeinfo/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/acrate-nodeinfo/tests" isTestSource="true" />
+      <sourceFolder url="file://$MODULE_DIR$/acrate-webfinger/src" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />

.idea/dataSources.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="DataSourceManagerImpl" format="xml" multifile-model="true">
+    <data-source source="LOCAL" name="acrate" uuid="8258414e-095d-430b-a0a5-b48e72af23a9">
+      <driver-ref>postgresql</driver-ref>
+      <synchronize>true</synchronize>
+      <jdbc-driver>org.postgresql.Driver</jdbc-driver>
+      <jdbc-url>jdbc:postgresql:///acrate</jdbc-url>
+      <working-dir>$ProjectFileDir$</working-dir>
+    </data-source>
+  </component>
+</project>

.idea/misc.xml

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="DiscordProjectSettings">
-    <option name="show" value="ASK" />
-    <option name="description" value="" />
-  </component>
-</project>

.idea/sqldialects.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="SqlDialectMappings">
+    <file url="file://$PROJECT_DIR$/acrate-core/migrations/2024-11-14-031744_meta/up.sql" dialect="GenericSQL" />
+  </component>
+</project>

Cargo.toml

@@ -1,3 +1,3 @@
 [workspace]
 resolver = "2"
-members = ["acrate-core", "acrate-hostmeta", "acrate-inbox", "acrate-nodeinfo"]
+members = ["acrate-core", "acrate-hostmeta", "acrate-inbox", "acrate-nodeinfo", "acrate-webfinger"]

README.md

@@ -11,3 +11,15 @@ Federation database
 > [!Caution]
 >
 > This software suite is in active development!
+
+## Crates
+
+### Libraries
+
+- `acrate-core`: Database stuff
+- `acrate-hostmeta`: RFC 6415 serde
+- `acrate-nodeinfo`: NodeInfo serde
+
+### Binaries
+
+- `acrate-webfinger`: WebFinger server

acrate-core/Cargo.toml

@@ -4,10 +4,10 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
-diesel = "2.2.4"
+diesel = { version = "2.2.4", features = ["postgres", "uuid"] }
+diesel-async = { version = "0.5.1", features = ["postgres"] }
 diesel_migrations = "2.2.0"
-acrate-hostmeta = { path = "../acrate-hostmeta" }
+uuid = "1.11.0"
-acrate-nodeinfo = { path = "../acrate-nodeinfo" }
 
 [lints.clippy]
 tabs-in-doc-comments = "allow"

acrate-core/migrations/2024-11-14-031744_meta/down.sql

@@ -0,0 +1,6 @@
+DROP TABLE IF EXISTS meta_properties CASCADE;
+DROP TABLE IF EXISTS meta_link_properties CASCADE;
+DROP TABLE IF EXISTS meta_link_titles CASCADE;
+DROP TABLE IF EXISTS meta_links CASCADE;
+DROP TABLE IF EXISTS meta_aliases CASCADE;
+DROP TABLE IF EXISTS meta_subjects CASCADE;

acrate-core/migrations/2024-11-14-031744_meta/up.sql

@@ -0,0 +1,63 @@
+CREATE TABLE IF NOT EXISTS meta_subjects (
+	id UUID DEFAULT gen_random_uuid(),
+	document BPCHAR NOT NULL,
+	pattern BPCHAR NOT NULL,
+	redirect BPCHAR,
+
+	PRIMARY KEY (id)
+);
+
+CREATE TABLE IF NOT EXISTS meta_aliases (
+	id UUID DEFAULT gen_random_uuid(),
+	document BPCHAR NOT NULL,
+	pattern BPCHAR NOT NULL,
+	alias BPCHAR NOT NULL,
+	
+	PRIMARY KEY (id)
+);
+
+CREATE TABLE IF NOT EXISTS meta_links (
+	id UUID DEFAULT gen_random_uuid(),
+	document BPCHAR NOT NULL,
+	pattern BPCHAR NOT NULL,
+	rel BPCHAR NOT NULL,
+	type BPCHAR,
+	href BPCHAR,
+	template BPCHAR,
+	
+	CONSTRAINT either_href_or_template_not_null CHECK (
+		(href IS NOT NULL AND template IS NULL)
+		OR
+		(href IS NULL AND template IS NOT NULL)
+	),
+	PRIMARY KEY (id)
+);
+
+CREATE TABLE IF NOT EXISTS meta_link_properties (
+	id UUID DEFAULT gen_random_uuid(),
+	meta_link_id UUID REFERENCES meta_links (id) NOT NULL,
+	rel BPCHAR NOT NULL,
+	value BPCHAR,
+	
+	PRIMARY KEY (id)
+);
+
+CREATE TABLE IF NOT EXISTS meta_properties (
+	id UUID DEFAULT gen_random_uuid(),
+	document BPCHAR NOT NULL,
+	pattern BPCHAR NOT NULL,
+	rel BPCHAR NOT NULL,
+	value BPCHAR,
+	
+	PRIMARY KEY (id)
+);
+
+CREATE TABLE IF NOT EXISTS meta_link_titles (
+	id UUID DEFAULT gen_random_uuid(),
+	meta_link_id UUID REFERENCES meta_links (id) NOT NULL,
+	language BPCHAR NOT NULL DEFAULT 'und',
+	value BPCHAR NOT NULL,
+
+	CONSTRAINT unique_languages UNIQUE (meta_link_id, language),
+	PRIMARY KEY(id)
+);

acrate-core/src/lib.rs

@@ -1,4 +1,8 @@
 //! Core crate of the `acrate` project.
 
-pub use acrate_nodeinfo as nodeinfo;
+mod schema;
-pub use acrate_hostmeta as hostmeta;
+
+pub mod meta;
+
+pub use diesel;
+pub use diesel_async;

acrate-core/src/meta.rs

@@ -0,0 +1,165 @@
+use diesel::{Associations, Identifiable, Insertable, QueryResult, Queryable, QueryableByName, Selectable, pg::Pg};
+use diesel_async::AsyncPgConnection;
+use uuid::Uuid;
+use super::schema;
+
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable)]
+#[diesel(table_name = schema::meta_subjects)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaSubject {
+	pub id: Uuid,
+	pub document: String,
+	pub pattern: String,
+	pub redirect: Option<String>,
+}
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable)]
+#[diesel(table_name = schema::meta_aliases)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaAlias {
+	pub id: Uuid,
+	pub document: String,
+	pub pattern: String,
+	pub alias: String,
+}
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable)]
+#[diesel(table_name = schema::meta_links)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaLink {
+	pub id: Uuid,
+	pub document: String,
+	pub pattern: String,
+	pub rel: String,
+	pub type_: Option<String>,
+	pub href: Option<String>,
+	pub template: Option<String>,
+}
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable, Associations)]
+#[diesel(belongs_to(MetaLink))]
+#[diesel(table_name = schema::meta_link_properties)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaLinkProperty {
+	pub id: Uuid,
+	pub meta_link_id: Uuid,
+	pub rel: String,
+	pub value: Option<String>,
+}
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable, Associations)]
+#[diesel(belongs_to(MetaLink))]
+#[diesel(table_name = schema::meta_link_titles)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaLinkTitle {
+	pub id: Uuid,
+	pub meta_link_id: Uuid,
+	pub language: String,
+	pub value: String,
+}
+
+#[derive(Debug, Queryable, QueryableByName, Identifiable, Selectable, Insertable)]
+#[diesel(table_name = schema::meta_properties)]
+#[diesel(check_for_backend(Pg))]
+pub struct MetaProperty {
+	pub id: Uuid,
+	pub document: String,
+	pub pattern: String,
+	pub rel: String,
+	pub value: Option<String>,
+}
+
+impl MetaSubject {
+	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject: &str) -> QueryResult<Vec<Self>> {
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		use schema::meta_subjects::dsl::*;
+		
+		let document_is_equal = document.eq(doc);
+		let subject_matches_pattern = subject.into_sql::<diesel::sql_types::Text>().ilike(pattern);
+		
+		meta_subjects
+			.filter(document_is_equal)
+			.filter(subject_matches_pattern)
+			.select(Self::as_select())
+			.load(conn)
+			.await
+	}
+}
+
+impl MetaAlias {
+	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject: &str) -> QueryResult<Vec<Self>> {
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		use schema::meta_aliases::dsl::*;
+		
+		let document_is_equal = document.eq(doc);
+		let subject_matches_pattern = subject.into_sql::<diesel::sql_types::Text>().ilike(pattern);
+		
+		meta_aliases
+			.filter(document_is_equal)
+			.filter(subject_matches_pattern)
+			.select(Self::as_select())
+			.load(conn)
+			.await
+	}
+}
+
+impl MetaLink {
+	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject: &str) -> QueryResult<Vec<Self>> {
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		use schema::meta_links::dsl::*;
+		
+		let document_is_equal = document.eq(doc);
+		let subject_matches_pattern = subject.into_sql::<diesel::sql_types::Text>().ilike(pattern);
+		
+		meta_links
+			.filter(document_is_equal)
+			.filter(subject_matches_pattern)
+			.select(Self::as_select())
+			.load(conn)
+			.await
+	}
+}
+
+impl MetaLinkProperty {
+	pub async fn query_by_link(conn: &mut AsyncPgConnection, links: &[MetaLink]) -> QueryResult<Vec<Self>> {
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		
+		Self::belonging_to(links)
+			.load(conn)
+			.await
+	}
+}
+
+impl MetaLinkTitle {
+	pub async fn query_by_link(conn: &mut AsyncPgConnection, links: &[MetaLink]) -> QueryResult<Vec<Self>> {
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		
+		Self::belonging_to(links)
+			.load(conn)
+			.await
+	}
+}
+
+impl MetaProperty {
+	pub async fn query_matching(conn: &mut AsyncPgConnection, doc: &str, subject: &str) -> QueryResult<Vec<Self>>	{
+		use diesel::prelude::*;
+		use diesel_async::RunQueryDsl;
+		use schema::meta_properties::dsl::*;
+		
+		let document_is_equal = document.eq(doc);
+		let subject_matches_pattern = subject.into_sql::<diesel::sql_types::Text>().ilike(pattern);
+		
+		meta_properties
+			.filter(document_is_equal)
+			.filter(subject_matches_pattern)
+			.select(Self::as_select())
+			.load(conn)
+			.await
+	}
+}

acrate-core/src/schema.rs

@@ -0,0 +1,72 @@
+// @generated automatically by Diesel CLI.
+
+diesel::table! {
+    meta_aliases (id) {
+        id -> Uuid,
+        document -> Bpchar,
+        pattern -> Bpchar,
+        alias -> Bpchar,
+    }
+}
+
+diesel::table! {
+    meta_link_properties (id) {
+        id -> Uuid,
+        meta_link_id -> Uuid,
+        rel -> Bpchar,
+        value -> Nullable<Bpchar>,
+    }
+}
+
+diesel::table! {
+    meta_link_titles (id) {
+        id -> Uuid,
+        meta_link_id -> Uuid,
+        language -> Bpchar,
+        value -> Bpchar,
+    }
+}
+
+diesel::table! {
+    meta_links (id) {
+        id -> Uuid,
+        document -> Bpchar,
+        pattern -> Bpchar,
+        rel -> Bpchar,
+        #[sql_name = "type"]
+        type_ -> Nullable<Bpchar>,
+        href -> Nullable<Bpchar>,
+        template -> Nullable<Bpchar>,
+    }
+}
+
+diesel::table! {
+    meta_properties (id) {
+        id -> Uuid,
+        document -> Bpchar,
+        pattern -> Bpchar,
+        rel -> Bpchar,
+        value -> Nullable<Bpchar>,
+    }
+}
+
+diesel::table! {
+    meta_subjects (id) {
+        id -> Uuid,
+        document -> Bpchar,
+        pattern -> Bpchar,
+        redirect -> Nullable<Bpchar>,
+    }
+}
+
+diesel::joinable!(meta_link_properties -> meta_links (meta_link_id));
+diesel::joinable!(meta_link_titles -> meta_links (meta_link_id));
+
+diesel::allow_tables_to_appear_in_same_query!(
+    meta_aliases,
+    meta_link_properties,
+    meta_link_titles,
+    meta_links,
+    meta_properties,
+    meta_subjects,
+);

acrate-hostmeta/src/jrd.rs

@@ -17,6 +17,7 @@ pub struct ResourceDescriptorJRD {
 	///
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.1>
 	///
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub subject: Option<String>,
 	
 	/// Other names the resource described by this document can be referred to.
@@ -70,6 +71,7 @@ pub struct ResourceDescriptorLinkJRD {
 	///
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.2>
 	///
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub r#type: Option<String>,
 	
 	/// URI to the resource put in relation.
@@ -78,6 +80,7 @@ pub struct ResourceDescriptorLinkJRD {
 	///
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.3>
 	///
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub href: Option<String>,
 	
 	/// Titles of the resource put in relation in various languages.
@@ -104,6 +107,7 @@ pub struct ResourceDescriptorLinkJRD {
 	///
 	/// - <https://datatracker.ietf.org/doc/html/rfc6415#section-4.2>
 	///
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub template: Option<String>,
 }
 
@@ -219,7 +223,7 @@ impl From<ResourceDescriptorLinkXRD> for ResourceDescriptorLinkJRD {
 
 impl From<ResourceDescriptorPropertyXRD> for (String, Option<String>) {
 	fn from(value: ResourceDescriptorPropertyXRD) -> Self {
-		(value.r#type, value.value)
+		(value.rel, value.value)
 	}
 }
 

acrate-hostmeta/src/xrd.rs

@@ -9,6 +9,7 @@ use crate::jrd::{ResourceDescriptorJRD, ResourceDescriptorLinkJRD};
 /// - <https://datatracker.ietf.org/doc/html/rfc6415#section-3>
 /// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4>
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename = "XRD")]
 pub struct ResourceDescriptorXRD {
 	/// The resource this document refers to.
 	///
@@ -17,6 +18,7 @@ pub struct ResourceDescriptorXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.1>
 	///
 	#[serde(rename = "Subject")]
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub subject: Option<String>,
 	
 	/// Other names the resource described by this document can be referred to.
@@ -58,6 +60,7 @@ pub struct ResourceDescriptorXRD {
 /// - <https://datatracker.ietf.org/doc/html/rfc6415#section-3.1.1>
 ///
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename = "Link")]
 pub struct ResourceDescriptorLinkXRD {
 	/// The kind of relation established by the subject with the attached resource.
 	///
@@ -75,6 +78,7 @@ pub struct ResourceDescriptorLinkXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.2>
 	///
 	#[serde(rename = "@type")]
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub r#type: Option<String>,
 	
 	/// URI to the resource put in relation.
@@ -84,6 +88,7 @@ pub struct ResourceDescriptorLinkXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.3>
 	///
 	#[serde(rename = "@href")]
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub href: Option<String>,
 	
 	/// Titles of the resource put in relation in various languages.
@@ -93,6 +98,7 @@ pub struct ResourceDescriptorLinkXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.4>
 	///
 	#[serde(default)]
+	#[serde(rename = "Title")]
 	pub titles: Vec<ResourceDescriptorTitleXRD>,
 	
 	/// Additional information about the resource put in relation.
@@ -102,6 +108,7 @@ pub struct ResourceDescriptorLinkXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.5>
 	///
 	#[serde(default)]
+	#[serde(rename = "Property")]
 	pub properties: Vec<ResourceDescriptorPropertyXRD>,
 	
 	/// Template to fill to get the URL to resource-specific information.
@@ -111,6 +118,7 @@ pub struct ResourceDescriptorLinkXRD {
 	/// - <https://datatracker.ietf.org/doc/html/rfc6415#section-4.2>
 	///
 	#[serde(rename = "@template")]
+	#[serde(skip_serializing_if = "Option::is_none")]
 	pub template: Option<String>,
 }
 
@@ -120,22 +128,26 @@ pub struct ResourceDescriptorLinkXRD {
 ///
 /// - <https://datatracker.ietf.org/doc/html/rfc7033#section-4.4.4.4>
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename = "Title")]
 pub struct ResourceDescriptorTitleXRD {
 	/// The language of the title.
 	#[serde(rename = "@lang")]
 	pub language: String,
 	
 	/// The title itself.
+	#[serde(rename = "$text")]
 	pub value: String,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename = "Property")]
 pub struct ResourceDescriptorPropertyXRD {
 	/// The property identifier, or type.
-	#[serde(alias = "@type")]
+	#[serde(rename = "@rel")]
-	pub r#type: String,
+	pub rel: String,
 	
 	/// The property value.
+    #[serde(rename = "$text")]
 	pub value: Option<String>,
 }
 
@@ -234,7 +246,7 @@ impl From<ResourceDescriptorJRD> for ResourceDescriptorXRD {
 impl From<(String, Option<String>)> for ResourceDescriptorPropertyXRD {
 	fn from(value: (String, Option<String>)) -> Self {
 		Self {
-			r#type: value.0,
+			rel: value.0,
 			value: value.1,
 		}
 	}

acrate-webfinger/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "acrate-webfinger"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+acrate-core = { path = "../acrate-core" }
+acrate-hostmeta = { path = "../acrate-hostmeta" }
+anyhow = "1.0.93"
+axum = { version = "0.7.7", features = ["macros"] }
+axum-extra = { version = "0.9.4", features = ["query"] }
+log = "0.4.22"
+micronfig = "0.3.0"
+minijinja = "2.5.0"
+pretty_env_logger = "0.5.0"
+quick-xml = { version = "0.37.0", features = ["serialize"] }
+serde = { version = "1.0.215", features = ["derive"] }
+serde_json = "1.0.132"
+tokio = { version = "1.41.1", features = ["macros", "net", "rt-multi-thread"] }

acrate-webfinger/src/config.rs

@@ -0,0 +1,4 @@
+micronfig::config!(
+	ACRATE_WEBFINGER_DATABASE_URL: String,
+	ACRATE_WEBFINGER_BIND_ADDRESS: String,
+);

acrate-webfinger/src/main.rs

@@ -0,0 +1,41 @@
+use std::sync::Arc;
+use anyhow::Context;
+use axum::Extension;
+
+mod config;
+mod route;
+
+
+#[tokio::main]
+async fn main() -> anyhow::Result<std::convert::Infallible> {
+	pretty_env_logger::init();
+	log::debug!("Logging initialized!");
+	
+	log::trace!("Creating Minijinja environment...");
+	let mut mj = minijinja::Environment::<'static>::new();
+	
+	log::trace!("Adding webfinger page to the Minijinja environment...");
+	mj.add_template("webfinger.html.j2", include_str!("webfinger.html.j2"))
+		.expect("webfinger.html.j2 to be a valid Minijinja template");
+
+	log::trace!("Creating Axum router...");
+	let app = axum::Router::new()
+		.route("/.well-known/webfinger", axum::routing::get(route::webfinger_handler))
+		.layer(Extension(Arc::new(mj)));
+	log::trace!("Axum router created successfully!");
+
+	log::trace!("Creating Tokio listener...");
+	let bind_address = config::ACRATE_WEBFINGER_BIND_ADDRESS();
+	let listener = tokio::net::TcpListener::bind(bind_address)
+		.await
+		.context("failed to bind listener to address")?;
+	log::trace!("Tokio listener bound to: {bind_address}");
+
+	log::debug!("Starting server...");
+	axum::serve(listener, app)
+		.await
+		.context("server exited with error")?;
+
+	log::error!("Server exited with no error, panicking.");
+	panic!("server exited with no error");
+}

acrate-webfinger/src/route.rs

@@ -0,0 +1,290 @@
+use std::sync::Arc;
+use axum::Extension;
+use axum::http::{HeaderMap, Response, StatusCode};
+use axum_extra::extract::Query;
+use serde::Deserialize;
+use acrate_core::diesel::GroupedBy;
+use acrate_core::diesel_async::{AsyncConnection, AsyncPgConnection};
+use acrate_core::meta::{MetaAlias, MetaLink, MetaLinkProperty, MetaLinkTitle, MetaProperty, MetaSubject};
+use acrate_hostmeta::jrd::ResourceDescriptorLinkJRD;
+use acrate_hostmeta::xrd::{ResourceDescriptorLinkXRD, ResourceDescriptorPropertyXRD, ResourceDescriptorTitleXRD};
+use crate::config;
+
+#[derive(Debug, Clone, Deserialize)]
+pub struct WebfingerQuery {
+	pub resource: Option<String>,
+	
+	#[serde(default)]
+	pub rel: Vec<String>,
+}
+
+const WEBFINGER_DOC: &str = "/.well-known/webfinger";
+
+#[axum::debug_handler]
+pub async fn webfinger_handler(
+	Query(WebfingerQuery {resource, rel}): Query<WebfingerQuery>,
+	headers: HeaderMap,
+	Extension(mj): Extension<Arc<minijinja::Environment<'static>>>,
+) -> Result<Response<String>, StatusCode> {
+	log::info!("Handling a WebFinger request!");
+	
+	let resource = resource.unwrap_or_else(|| "".to_string());
+	log::debug!("Resource is: {resource:#?}");
+	
+	log::debug!("Rel is: {rel:#?}");
+	
+	let accept = headers.get("Accept")
+		.map(|v| v.to_str())
+		.filter(Result::is_ok)
+		.map(|v| v.unwrap())
+		.unwrap_or("application/json")
+		.to_string();
+	log::debug!("Accept is: {accept:#?}");
+	
+	let mut response = Response::new("".to_string());
+	
+	let mut conn = AsyncPgConnection::establish(config::ACRATE_WEBFINGER_DATABASE_URL())
+		.await
+		.map_err(|_| StatusCode::BAD_GATEWAY)?;
+	
+	let subjects = MetaSubject::query_matching(&mut conn, WEBFINGER_DOC, &resource)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+	let subject = subjects.first()
+		.ok_or(StatusCode::NOT_FOUND)?;
+
+	if subject.redirect.is_some() {
+		{
+			let headers = response.headers_mut();
+			headers.insert(
+				"Location",
+				subject.redirect
+					.as_ref()
+					.expect("redirect not to have become suddenly None")
+					.parse()
+					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+			);
+		}
+		{
+			let status = response.status_mut();
+			*status = StatusCode::FOUND;
+		}
+
+		return Ok(response);
+	}
+
+	let aliases = MetaAlias::query_matching(&mut conn, WEBFINGER_DOC, &resource)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+	
+	let properties = MetaProperty::query_matching(&mut conn, WEBFINGER_DOC, &resource)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+	
+	let links = MetaLink::query_matching(&mut conn, WEBFINGER_DOC, &resource)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+	
+	let link_properties = MetaLinkProperty::query_by_link(&mut conn, &links)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+		.grouped_by(&links);
+	
+	let link_titles = MetaLinkTitle::query_by_link(&mut conn, &links)
+		.await
+		.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?
+		.grouped_by(&links);
+	
+	let links_full: Vec<(MetaLink, Vec<MetaLinkProperty>, Vec<MetaLinkTitle>)> = links
+		.into_iter()
+		.zip(link_properties)
+		.zip(link_titles)
+		.map(|((link, properties), titles)| (link, properties, titles))
+		.collect();
+	
+	{
+		let headers = response.headers_mut();
+		headers.insert(
+			"Access-Control-Allow-Origin",
+			"*".parse().unwrap()
+		);
+	}
+	
+	for mime in accept.split(",") {
+		{
+			let headers = response.headers_mut();
+			headers.insert(
+				"Content-Type",
+				mime.parse().map_err(|_| StatusCode::BAD_REQUEST)?
+			);
+		}
+
+		let (mime, _params) = match mime.trim().split_once(";") {
+			Some((mime, params)) => (mime, Some(params)),
+			None => (mime, None),
+		};
+
+		match mime {
+			"*/*" | "application/json" | "application/jrd+json" => {
+				let subject = Some(resource);
+				
+				let aliases = aliases
+					.into_iter()
+					.map(|alias| alias.alias)
+					.collect();
+				
+				let properties = properties
+					.into_iter()
+					.map(|prop| (prop.rel, prop.value))
+					.collect();
+				
+				let links = links_full
+					.into_iter()
+					.map(|(link, properties, titles)| ResourceDescriptorLinkJRD {
+						rel: link.rel,
+						r#type: link.type_,
+						href: link.href,
+						template: link.template,
+						properties: properties
+							.into_iter()
+							.map(|property| (property.rel, property.value))
+							.collect(),
+						titles: titles
+							.into_iter()
+							.map(|title| (title.language, title.value))
+							.collect(),
+					})
+					.collect::<Vec<ResourceDescriptorLinkJRD>>();
+				
+				let rd = acrate_hostmeta::jrd::ResourceDescriptorJRD {
+					subject,
+					aliases,
+					properties,
+					links,
+				};
+				
+				let json = serde_json::to_string_pretty(&rd)
+					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+				
+				{
+					let body = response.body_mut();
+					body.push_str(&json);
+				}
+				
+				return Ok(response);
+			},
+			"application/xml" | "application/xrd+xml" => {
+				let subject = Some(resource);
+				
+				let aliases = aliases
+					.into_iter()
+					.map(|alias| alias.alias)
+					.collect();
+				
+				let properties: Vec<ResourceDescriptorPropertyXRD> = properties
+					.into_iter()
+					.map(|prop| ResourceDescriptorPropertyXRD {
+						rel: prop.rel,
+						value: prop.value,
+					})
+					.collect();
+				
+				let links = links_full
+					.into_iter()
+					.map(|(link, properties, titles)| ResourceDescriptorLinkXRD {
+						rel: link.rel,
+						r#type: link.type_,
+						href: link.href,
+						template: link.template,
+						properties: properties
+							.into_iter()
+							.map(|property| ResourceDescriptorPropertyXRD {
+								rel: property.rel,
+								value: property.value,
+							})
+							.collect(),
+						titles: titles
+							.into_iter()
+							.map(|title| ResourceDescriptorTitleXRD {
+								language: title.language,
+								value: title.value,
+							})
+							.collect(),
+					})
+					.collect::<Vec<ResourceDescriptorLinkXRD>>();
+				
+				let rd = acrate_hostmeta::xrd::ResourceDescriptorXRD {
+					subject,
+					aliases,
+					properties,
+					links,
+				};
+				
+				let xml = quick_xml::se::to_string(&rd)
+					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+				
+				{
+					let body = response.body_mut();
+					body.push_str(r#"<?xml version="1.0" encoding="UTF-8"?>"#);
+					body.push_str(&xml);
+				}
+				
+				return Ok(response);
+			},
+			"text/html" => {
+				let aliases: Vec<String> = aliases.into_iter()
+					.map(|alias| alias.alias)
+					.collect();
+
+				let properties: Vec<(String, Option<String>)> = properties.into_iter()
+					.map(|prop| {
+						(prop.rel, prop.value)
+					})
+					.collect();
+
+				let links: Vec<(String, Option<String>, Option<String>, Option<String>, Vec<(String, Option<String>)>, Vec<(String, String)>)> = links_full
+					.into_iter()
+					.map(|(link, properties, titles)| {
+						(
+							link.rel,
+							link.type_,
+							link.href,
+							link.template,
+							properties.into_iter()
+								.map(|prop| (prop.rel, prop.value))
+								.collect::<Vec<(String, Option<String>)>>(),
+							titles.into_iter()
+								.map(|title| (title.language, title.value))
+								.collect::<Vec<(String, String)>>()
+						)
+					})
+					.collect();
+
+				let html = mj.get_template("webfinger.html.j2")
+					.expect("webfinger.html.j2 to exist")
+					.render(
+						minijinja::context!(
+							subject => resource,
+							aliases => aliases,
+							properties => properties,
+							links => links,
+						)
+					)
+					.map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+
+				{
+					let body = response.body_mut();
+					body.push_str(&html);
+				}
+				
+				return Ok(response);
+			},
+			_ => {
+				continue;
+			},
+		}
+	}
+	
+	Err(StatusCode::NOT_ACCEPTABLE)
+}

acrate-webfinger/src/webfinger.html.j2

@@ -0,0 +1,192 @@
+<!DOCTYPE html>
+<head>
+	<meta charset="UTF-8">
+	<title>{{ subject }} · Acrate Webfinger</title>
+	<style>
+		:root {
+			--wf-yellow: #e2bb03;
+			--wf-brown: #3b351d;
+			--link-color: #0094b9;
+		}
+
+		body {
+			font-family: sans-serif;
+		}
+
+		h1, h2 {
+			text-align: center;
+		}
+
+		main {
+			max-width: 800px;
+			padding: 8px;
+			margin: 0 auto;
+			
+			border: 2px solid currentColor;
+			border-radius: 8px;
+		}
+
+		a {
+			color: var(--link-color);
+		}
+
+		hr {
+			margin: 8px -8px;
+			border: 1px solid currentColor;
+			opacity: 1;
+		}
+
+		small span {
+			font-family: monospace;
+		}
+
+		@media screen {
+			main {
+				box-shadow: 4px 4px 10px currentColor;
+			}
+		}
+
+		@media screen and (prefers-color-scheme: dark) {
+			body {
+				background-color: black;
+				color: var(--wf-yellow);
+			}
+
+			main {
+				background-color: var(--wf-brown);
+			}
+
+			main, hr {
+				border-color: var(--wf-yellow);
+			}
+		}
+
+		@media screen and (prefers-color-scheme: light) {
+			body {
+				background-color: var(--wf-yellow);
+				color: var(--wf-brown);
+			}
+
+			main {
+				background-color: white;
+			}
+
+			main, hr {
+				border-color: var(--wf-brown);
+			}
+		}
+	</style>
+</head>
+<body>
+	<header>
+		<h1>
+			Acrate Webfinger
+		</h1>
+	</header>
+	<main>
+		<h2 id="section-subject">
+			<span id="subject">{{ subject }}</span>
+		</h2>
+		{% if aliases %}
+			<hr>
+			<section id="section-aliases">
+				<h3>
+					Aliases
+				</h3>
+				<ul>
+					{% for alias in aliases %}
+						<li><a href="{{ alias }}">{{ alias }}</a></li>
+					{% endfor %}
+				</ul>
+			</section>
+		{% endif %}
+		{% if properties %}
+			<hr>
+			<section id="section-properties">
+				<h3>
+					Properties
+				</h3>
+				<dl>
+					{% for property in properties %}
+						<dt>
+							<a href="{{ property[0] }}">{{ property[0] }}</a>
+						</dt>
+						<dd>
+							<span>{{ property[1] }}</span>
+						</dd>
+					{% endfor %}
+				</dl>
+			</section>
+		{% endif %}
+		{% if links %}
+			<hr>
+			<section id="section-links">
+				<h3>
+					Links
+				</h3>
+				<dl>
+					{% for link in links %}
+						<dt>
+							<h4>
+								{% if link[0] != "self" %}
+									<a href="{{ link[0] }}">{{ link[0] }}</a>
+								{% else %}
+									<span>{{ link[0] }}</span>
+								{% endif %}
+								{% if link[1] is not none %}
+									<small>
+										(<span>{{ link[1] }}</span>)
+									</small>
+								{% endif %}
+							</h4>
+						</dt>
+						<dd>
+							{% if link[2] is not none %}
+								<h5>
+									Link destination
+								</h5>
+								<a href="{{ link[2] }}">{{ link[2] }}</a>
+							{% endif %}
+							{% if link[3] is not none %}
+								<h5>
+									Link template
+								</h5>
+								<span>{{ link[3] }}</span>
+							{% endif %}
+							{% if link[4] %}
+								<h5>
+									Link properties
+								</h5>
+								<dl>
+									{% for property in link[4] %}
+										<dt>
+											<a href="{{ property[0] }}">{{ property[0] }}</a>
+										</dt>
+										<dd>
+											<span>{{ property[1] }}</span>
+										</dd>
+									{% endfor %}
+								</dl>
+							{% endif %}
+							{% if link[5] %}
+								<h5>
+									Link titles
+								</h5>
+								<dl>
+									{% for title in link[5] %}
+										<dt>
+											<span>{{ title[0] }}</span>
+										</dt>
+										<dd>
+											<span>{{ title[1] }}</span>
+										</dd>
+									{% endfor %}
+								</dl>
+							{% endif %}
+						</dd>
+					{% endfor %}
+				</dl>
+			</section>
+		{% endif %}
+	</main>
+</body>