Add endpoints for deleting channels and messages.

It is deliberate that the expire() functions do not use them. To avoid races, the transactions must be committed before events get sent, in both cases, which makes them structurally pretty different.

4 files changed, 115 insertions, 41 deletions

diff --git a/src/message/app.rs b/src/message/app.rs
index 51f772e..1d34c14 100644
--- a/src/message/app.rs
+++ b/src/message/app.rs
@@ -2,12 +2,12 @@ use chrono::TimeDelta;
 use itertools::Itertools;
 use sqlx::sqlite::SqlitePool;
 
-use super::{repo::Provider as _, Message};
+use super::{repo::Provider as _, Id, Message};
 use crate::{
     channel::{self, repo::Provider as _},
     clock::DateTime,
     db::NotFound as _,
-    event::{broadcaster::Broadcaster, repo::Provider as _, Sequence},
+    event::{broadcaster::Broadcaster, repo::Provider as _, Event, Sequence},
     login::Login,
 };
 
@@ -27,13 +27,13 @@ impl<'a> Messages<'a> {
         sender: &Login,
         sent_at: &DateTime,
         body: &str,
-    ) -> Result<Message, Error> {
+    ) -> Result<Message, SendError> {
         let mut tx = self.db.begin().await?;
         let channel = tx
             .channels()
             .by_id(channel)
             .await
-            .not_found(|| Error::ChannelNotFound(channel.clone()))?;
+            .not_found(|| SendError::ChannelNotFound(channel.clone()))?;
         let sent = tx.sequence().next(sent_at).await?;
         let message = tx
             .messages()
@@ -41,24 +41,40 @@ impl<'a> Messages<'a> {
             .await?;
         tx.commit().await?;
 
-        for event in message.events() {
-            self.events.broadcast(event);
-        }
+        self.events
+            .broadcast(message.events().map(Event::from).collect::<Vec<_>>());
 
         Ok(message.snapshot())
     }
 
+    pub async fn delete(&self, message: &Id, deleted_at: &DateTime) -> Result<(), DeleteError> {
+        let mut tx = self.db.begin().await?;
+        let deleted = tx.sequence().next(deleted_at).await?;
+        let message = tx.messages().delete(message, &deleted).await?;
+        tx.commit().await?;
+
+        self.events.broadcast(
+            message
+                .events()
+                .filter(Sequence::start_from(deleted.sequence))
+                .map(Event::from)
+                .collect::<Vec<_>>(),
+        );
+
+        Ok(())
+    }
+
     pub async fn expire(&self, relative_to: &DateTime) -> Result<(), sqlx::Error> {
         // Somewhat arbitrarily, expire after 90 days.
         let expire_at = relative_to.to_owned() - TimeDelta::days(90);
 
         let mut tx = self.db.begin().await?;
-        let expired = tx.messages().expired(&expire_at).await?;
 
+        let expired = tx.messages().expired(&expire_at).await?;
         let mut events = Vec::with_capacity(expired.len());
-        for (channel, message) in expired {
+        for message in expired {
             let deleted = tx.sequence().next(relative_to).await?;
-            let message = tx.messages().delete(&channel, &message, &deleted).await?;
+            let message = tx.messages().delete(&message, &deleted).await?;
             events.push(
                 message
                     .events()
@@ -68,21 +84,32 @@ impl<'a> Messages<'a> {
 
         tx.commit().await?;
 
-        for event in events
-            .into_iter()
-            .kmerge_by(|a, b| a.instant.sequence < b.instant.sequence)
-        {
-            self.events.broadcast(event);
-        }
+        self.events.broadcast(
+            events
+                .into_iter()
+                .kmerge_by(|a, b| a.instant.sequence < b.instant.sequence)
+                .map(Event::from)
+                .collect::<Vec<_>>(),
+        );
 
         Ok(())
     }
 }
 
 #[derive(Debug, thiserror::Error)]
-pub enum Error {
+pub enum SendError {
+    #[error("channel {0} not found")]
+    ChannelNotFound(channel::Id),
+    #[error(transparent)]
+    DatabaseError(#[from] sqlx::Error),
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum DeleteError {
     #[error("channel {0} not found")]
     ChannelNotFound(channel::Id),
+    #[error("message {0} not found")]
+    NotFound(Id),
     #[error(transparent)]
     DatabaseError(#[from] sqlx::Error),
 }
diff --git a/src/message/mod.rs b/src/message/mod.rs
index 52d56c1..a8f51ab 100644
--- a/src/message/mod.rs
+++ b/src/message/mod.rs
@@ -3,6 +3,7 @@ pub mod event;
 mod history;
 mod id;
 pub mod repo;
+mod routes;
 mod snapshot;
 
-pub use self::{event::Event, history::History, id::Id, snapshot::Message};
+pub use self::{event::Event, history::History, id::Id, routes::router, snapshot::Message};
diff --git a/src/message/repo.rs b/src/message/repo.rs
index 3b2b8f7..ae41736 100644
--- a/src/message/repo.rs
+++ b/src/message/repo.rs
@@ -62,7 +62,25 @@ impl<'c> Messages<'c> {
         Ok(message)
     }
 
-    async fn by_id(&mut self, channel: &Channel, message: &Id) -> Result<History, sqlx::Error> {
+    pub async fn in_channel(&mut self, channel: &Channel) -> Result<Vec<Id>, sqlx::Error> {
+        let messages = sqlx::query_scalar!(
+            r#"
+                select
+                    message.id as "id: Id"
+                from message
+                    join channel on message.channel = channel.id
+                where channel.id = $1
+                order by message.sent_sequence
+            "#,
+            channel.id,
+        )
+        .fetch_all(&mut *self.0)
+        .await?;
+
+        Ok(messages)
+    }
+
+    async fn by_id(&mut self, message: &Id) -> Result<History, sqlx::Error> {
         let message = sqlx::query!(
             r#"
                 select
@@ -78,10 +96,8 @@ impl<'c> Messages<'c> {
                     join channel on message.channel = channel.id
                     join login as sender on message.sender = sender.id
                 where message.id = $1
-                    and message.channel = $2
             "#,
             message,
-            channel.id,
         )
         .map(|row| History {
             message: Message {
@@ -110,11 +126,10 @@ impl<'c> Messages<'c> {
 
     pub async fn delete(
         &mut self,
-        channel: &Channel,
         message: &Id,
         deleted: &Instant,
     ) -> Result<History, sqlx::Error> {
-        let history = self.by_id(channel, message).await?;
+        let history = self.by_id(message).await?;
 
         sqlx::query_scalar!(
             r#"
@@ -134,31 +149,16 @@ impl<'c> Messages<'c> {
         })
     }
 
-    pub async fn expired(
-        &mut self,
-        expire_at: &DateTime,
-    ) -> Result<Vec<(Channel, Id)>, sqlx::Error> {
-        let messages = sqlx::query!(
+    pub async fn expired(&mut self, expire_at: &DateTime) -> Result<Vec<Id>, sqlx::Error> {
+        let messages = sqlx::query_scalar!(
             r#"
                 select
-                    channel.id as "channel_id: channel::Id",
-                    channel.name as "channel_name",
-                    message.id as "message: Id"
+                    id as "message: Id"
                 from message
-                    join channel on message.channel = channel.id
                 where sent_at < $1
             "#,
             expire_at,
         )
-        .map(|row| {
-            (
-                Channel {
-                    id: row.channel_id,
-                    name: row.channel_name,
-                },
-                row.message,
-            )
-        })
         .fetch_all(&mut *self.0)
         .await?;
 
diff --git a/src/message/routes.rs b/src/message/routes.rs
new file mode 100644
index 0000000..29fe3d7
--- /dev/null
+++ b/src/message/routes.rs
@@ -0,0 +1,46 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::{IntoResponse, Response},
+    routing::delete,
+    Router,
+};
+
+use crate::{
+    app::App,
+    clock::RequestedAt,
+    error::Internal,
+    login::Login,
+    message::{self, app::DeleteError},
+};
+
+pub fn router() -> Router<App> {
+    Router::new().route("/api/messages/:message", delete(on_delete))
+}
+
+async fn on_delete(
+    State(app): State<App>,
+    Path(message): Path<message::Id>,
+    RequestedAt(deleted_at): RequestedAt,
+    _: Login,
+) -> Result<StatusCode, ErrorResponse> {
+    app.messages().delete(&message, &deleted_at).await?;
+
+    Ok(StatusCode::ACCEPTED)
+}
+
+#[derive(Debug, thiserror::Error)]
+#[error(transparent)]
+struct ErrorResponse(#[from] DeleteError);
+
+impl IntoResponse for ErrorResponse {
+    fn into_response(self) -> Response {
+        let Self(error) = self;
+        match error {
+            not_found @ (DeleteError::ChannelNotFound(_) | DeleteError::NotFound(_)) => {
+                (StatusCode::NOT_FOUND, not_found.to_string()).into_response()
+            }
+            other => Internal::from(other).into_response(),
+        }
+    }
+}