update community backend

crates/community/src/community.rs

@@ -1 +1,229 @@
+use std::collections::{BTreeMap, BTreeSet};
+use std::sync::Arc;
 
+use anyhow::Result;
+use concord::cord02::ControlFold;
+use concord::store::{ChannelKeyRef, CommunityState};
+use concord::{ChannelId, CommunityId, Epoch};
+use gpui::{AppContext, Context, EventEmitter, Task};
+use nostr_sdk::prelude::*;
+
+use crate::sync::{self, Snapshot};
+
+/// Everything that decides which planes a community is subscribed to. The
+/// registry re-subscribes only when this changes.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SubscriptionKey {
+    control_pks: BTreeMap<u64, PublicKey>,
+    channels: Vec<(ChannelId, Epoch, bool)>,
+    relays: Vec<RelayUrl>,
+}
+
+impl SubscriptionKey {
+    fn of(state: &CommunityState) -> Self {
+        Self {
+            control_pks: state.control_pks.clone(),
+            channels: state
+                .channels
+                .iter()
+                .map(|channel| (channel.id, channel.epoch, channel.private))
+                .collect(),
+            relays: state.relays.clone(),
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum CommunityEvent {
+    Updated(CommunityId),
+    Error(String),
+}
+
+pub struct Community {
+    state: CommunityState,
+    control: ControlFold,
+    members: BTreeSet<PublicKey>,
+    database: Arc<dyn NostrDatabase>,
+    dirty: bool,
+    refresh_task: Option<Task<Result<()>>>,
+}
+
+impl EventEmitter<CommunityEvent> for Community {}
+
+impl Community {
+    pub fn new(state: CommunityState, database: Arc<dyn NostrDatabase>) -> Self {
+        Self {
+            state,
+            control: ControlFold::default(),
+            members: BTreeSet::new(),
+            database,
+            dirty: false,
+            refresh_task: None,
+        }
+    }
+
+    pub fn id(&self) -> CommunityId {
+        self.state.id
+    }
+
+    pub fn state(&self) -> &CommunityState {
+        &self.state
+    }
+
+    pub fn control(&self) -> &ControlFold {
+        &self.control
+    }
+
+    pub fn members(&self) -> &BTreeSet<PublicKey> {
+        &self.members
+    }
+
+    pub fn channels(&self) -> &[ChannelKeyRef] {
+        &self.state.channels
+    }
+
+    pub fn subscription_key(&self) -> SubscriptionKey {
+        SubscriptionKey::of(&self.state)
+    }
+
+    /// Rebuilds the community from the wraps in the local database. A burst of
+    /// signals produces at most two folds: one running, one owed.
+    pub fn refresh(&mut self, cx: &mut Context<Self>) {
+        if self.refresh_task.is_some() {
+            self.dirty = true;
+            return;
+        }
+
+        let database = self.database.clone();
+        let state = self.state.clone();
+        let folded =
+            cx.background_spawn(async move { sync::fold(database.as_ref(), &state).await });
+
+        self.refresh_task = Some(cx.spawn(async move |this, cx| {
+            let result = folded.await;
+            this.update(cx, |this, cx| this.apply(result, cx))?;
+            Ok(())
+        }));
+    }
+
+    fn apply(&mut self, result: Result<Option<Snapshot>>, cx: &mut Context<Self>) {
+        self.refresh_task = None;
+
+        match result {
+            Ok(Some(snapshot)) => {
+                self.state = snapshot.state;
+                self.control = snapshot.control;
+                self.members = snapshot.members;
+                cx.emit(CommunityEvent::Updated(self.state.id));
+                cx.notify();
+            }
+            Ok(None) => {}
+            Err(error) => cx.emit(CommunityEvent::Error(error.to_string())),
+        }
+
+        if self.dirty {
+            self.dirty = false;
+            self.refresh(cx);
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use concord::cord02::GENERAL_CHANNEL;
+    use concord::cord02::guestbook::{build_join, build_leave, seal_rumor};
+    use concord::derive::guestbook_group_key;
+    use concord::store::{load_state, save_state};
+    use nostr_memory::MemoryDatabase;
+
+    use super::*;
+    use crate::sync::fixtures::{AT_MS, community};
+
+    #[test]
+    fn genesis_folds_into_metadata_channels_and_the_owner() {
+        smol::block_on(async {
+            let owner = Keys::generate();
+            let (genesis, state) = community(&owner);
+            let database = MemoryDatabase::unbounded();
+
+            for wrap in &genesis.wraps {
+                database.save_event(wrap).await.expect("saves wrap");
+            }
+            save_state(&database, &state).await.expect("saves state");
+
+            let snapshot = sync::fold(&database, &state)
+                .await
+                .expect("folds")
+                .expect("genesis is a control edition");
+
+            let metadata = snapshot.control.community.as_ref().expect("metadata");
+            assert_eq!(metadata.name, "Room");
+
+            let channel = snapshot
+                .control
+                .channels
+                .get(&genesis.channel_id)
+                .expect("general channel");
+            assert_eq!(channel.name, GENERAL_CHANNEL);
+            assert!(!channel.private);
+
+            assert_eq!(snapshot.members, BTreeSet::from([owner.public_key()]));
+
+            let persisted = load_state(&database, &state.id)
+                .await
+                .expect("loads")
+                .expect("persisted");
+            assert_eq!(persisted.id, state.id);
+        });
+    }
+
+    #[test]
+    fn a_join_adds_a_member_and_a_later_leave_removes_them() {
+        smol::block_on(async {
+            let owner = Keys::generate();
+            let member = Keys::generate();
+            let (genesis, state) = community(&owner);
+            let database = MemoryDatabase::unbounded();
+
+            for wrap in &genesis.wraps {
+                database.save_event(wrap).await.expect("saves wrap");
+            }
+            save_state(&database, &state).await.expect("saves state");
+
+            let guestbook = guestbook_group_key(&state.community_root, &state.id, state.root_epoch)
+                .expect("guestbook key");
+
+            let join = seal_rumor(
+                &build_join(member.public_key(), None, AT_MS + 1_000),
+                &guestbook,
+                &member,
+            )
+            .expect("seals join")
+            .0;
+            database.save_event(&join).await.expect("saves join");
+
+            let joined = sync::fold(&database, &state)
+                .await
+                .expect("folds")
+                .expect("control is still held");
+            assert!(joined.members.contains(&member.public_key()));
+            assert_eq!(joined.members.len(), 2);
+
+            let leave = seal_rumor(
+                &build_leave(member.public_key(), AT_MS + 2_000),
+                &guestbook,
+                &member,
+            )
+            .expect("seals leave")
+            .0;
+            database.save_event(&leave).await.expect("saves leave");
+
+            let left = sync::fold(&database, &joined.state)
+                .await
+                .expect("folds")
+                .expect("control is still held");
+            assert!(!left.members.contains(&member.public_key()));
+            assert_eq!(left.members, BTreeSet::from([owner.public_key()]));
+        });
+    }
+}

crates/community/src/lib.rs

@@ -3,6 +3,7 @@ use gpui::{App, Window};
 mod community;
 mod sync;
 
+pub use community::*;
 pub use sync::*;
 
 pub fn init(_window: &mut Window, _cx: &mut App) {}

crates/community/src/sync.rs

@@ -260,24 +260,22 @@ fn observe(observed: &mut BTreeMap<PublicKey, u64>, author: PublicKey, at_ms: u6
 }
 
 #[cfg(test)]
-mod tests {
+pub(crate) mod fixtures {
-    use concord::cord02::list::{CommunityListEntry, JoinMaterial, Tombstone, build_list_event};
+    use concord::cord02::{CommunityGenesis, CommunityMetadata, ROOT_EPOCH};
-    use concord::cord02::{CommunityMetadata, ROOT_EPOCH, genesis, open_edition};
     use concord::cord04::ParsedEdition;
     use concord::derive::control_signer_group_key;
-    use concord::store::save_state;
-    use nostr_memory::MemoryDatabase;
 
     use super::*;
 
-    const AT_MS: u64 = 1_719_800_000_000;
+    pub const AT_MS: u64 = 1_719_800_000_000;
 
-    fn community(owner: &Keys) -> CommunityState {
+    /// A genesis and the state it folds into, ready for a test database.
+    pub fn community(owner: &Keys) -> (CommunityGenesis, CommunityState) {
         let metadata = CommunityMetadata {
             name: "Room".to_owned(),
             ..Default::default()
         };
-        let genesis = genesis(owner, &metadata, AT_MS / 1000).expect("genesis");
+        let genesis = cord02::genesis(owner, &metadata, AT_MS / 1000).expect("genesis");
         let read = control_group_key(
             &genesis.community_root,
             &genesis.identity.community_id,
@@ -295,11 +293,24 @@ mod tests {
         let editions: Vec<ParsedEdition> = genesis
             .wraps
             .iter()
-            .map(|wrap| open_edition(wrap, &read, &address, true).expect("opens"))
+            .map(|wrap| cord02::open_edition(wrap, &read, &address, true).expect("opens"))
             .collect();
 
-        CommunityState::from_genesis(&genesis, &editions, AT_MS).expect("state")
+        let state = CommunityState::from_genesis(&genesis, &editions, AT_MS).expect("state");
+
+        (genesis, state)
     }
+}
+
+#[cfg(test)]
+mod tests {
+    use concord::cord02::ROOT_EPOCH;
+    use concord::cord02::list::{CommunityListEntry, JoinMaterial, Tombstone, build_list_event};
+    use concord::store::save_state;
+    use nostr_memory::MemoryDatabase;
+
+    use super::fixtures::{AT_MS, community};
+    use super::*;
 
     fn material(state: &CommunityState) -> JoinMaterial {
         JoinMaterial {
@@ -332,7 +343,7 @@ mod tests {
     #[test]
     fn every_held_plane_routes_by_its_wrap_author() {
         let owner = Keys::generate();
-        let state = community(&owner);
+        let state = community(&owner).1;
         let planes = planes(&state).expect("planes");
 
         assert_eq!(
@@ -356,7 +367,7 @@ mod tests {
             let keys = Keys::generate();
             let signer = UniversalSigner::new(keys.clone());
             let owner = Keys::generate();
-            let state = community(&owner);
+            let state = community(&owner).1;
 
             // With no list event, every state document is a community.
             let no_list = MemoryDatabase::unbounded();