graphql: API to set the user displayname (#1412)

crates/graphql/src/mutations/matrix.rs

@@ -0,0 +1,115 @@
+// Copyright 2023 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use anyhow::Context as _;
+use async_graphql::{Context, Description, Enum, InputObject, Object, ID};
+
+use crate::{
+    model::{NodeType, User},
+    state::ContextExt,
+};
+
+#[derive(Default)]
+pub struct MatrixMutations {
+    _private: (),
+}
+
+/// The input for the `addEmail` mutation
+#[derive(InputObject)]
+struct SetDisplayNameInput {
+    /// The ID of the user to add the email address to
+    user_id: ID,
+
+    /// The display name to set. If `None`, the display name will be removed.
+    display_name: Option<String>,
+}
+
+/// The status of the `setDisplayName` mutation
+#[derive(Enum, Copy, Clone, Eq, PartialEq)]
+pub enum SetDisplayNameStatus {
+    /// The display name was set
+    Set,
+    /// The display name is invalid
+    Invalid,
+}
+
+/// The payload of the `setDisplayName` mutation
+#[derive(Description)]
+enum SetDisplayNamePayload {
+    Set(User),
+    Invalid,
+}
+
+#[Object(use_type_description)]
+impl SetDisplayNamePayload {
+    /// Status of the operation
+    async fn status(&self) -> SetDisplayNameStatus {
+        match self {
+            SetDisplayNamePayload::Set(_) => SetDisplayNameStatus::Set,
+            SetDisplayNamePayload::Invalid => SetDisplayNameStatus::Invalid,
+        }
+    }
+
+    /// The user that was updated
+    async fn user(&self) -> Option<&User> {
+        match self {
+            SetDisplayNamePayload::Set(user) => Some(user),
+            SetDisplayNamePayload::Invalid => None,
+        }
+    }
+}
+
+#[Object]
+impl MatrixMutations {
+    /// Set the display name of a user
+    async fn set_display_name(
+        &self,
+        ctx: &Context<'_>,
+        input: SetDisplayNameInput,
+    ) -> Result<SetDisplayNamePayload, async_graphql::Error> {
+        let state = ctx.state();
+        let id = NodeType::User.extract_ulid(&input.user_id)?;
+        let requester = ctx.requester();
+
+        let user = requester.user().context("Unauthorized")?;
+
+        if user.id != id {
+            return Err(async_graphql::Error::new("Unauthorized"));
+        }
+
+        let conn = state.homeserver_connection();
+        let mxid = conn.mxid(&user.username);
+
+        if let Some(display_name) = &input.display_name {
+            // Let's do some basic validation on the display name
+            if display_name.len() > 256 {
+                return Ok(SetDisplayNamePayload::Invalid);
+            }
+
+            if display_name.is_empty() {
+                return Ok(SetDisplayNamePayload::Invalid);
+            }
+
+            conn.set_displayname(&mxid, display_name)
+                .await
+                .context("Failed to set display name")?;
+        } else {
+            conn.unset_displayname(&mxid)
+                .await
+                .context("Failed to unset display name")?;
+        }
+
+        Ok(SetDisplayNamePayload::Set(User(user.clone())))
+    }
+}

crates/graphql/src/mutations/mod.rs

@@ -14,6 +14,7 @@
 
 mod browser_session;
 mod compat_session;
+mod matrix;
 mod oauth2_session;
 mod user_email;
 
@@ -26,6 +27,7 @@ pub struct Mutation(
     oauth2_session::OAuth2SessionMutations,
     compat_session::CompatSessionMutations,
     browser_session::BrowserSessionMutations,
+    matrix::MatrixMutations,
 );
 
 impl Mutation {