Merge branch 'main' into feature-frontend

1 files changed, 38 insertions, 0 deletions

diff --git a/src/channel/snapshot.rs b/src/channel/snapshot.rs
new file mode 100644
index 0000000..6462f25
--- /dev/null
+++ b/src/channel/snapshot.rs
@@ -0,0 +1,38 @@
+use super::{
+    event::{Created, Event, Kind},
+    Id,
+};
+
+#[derive(Clone, Debug, Eq, PartialEq, serde::Serialize)]
+pub struct Channel {
+    pub id: Id,
+    pub name: String,
+}
+
+impl Channel {
+    fn apply(state: Option<Self>, event: Event) -> Option<Self> {
+        match (state, event.kind) {
+            (None, Kind::Created(event)) => Some(event.into()),
+            (Some(channel), Kind::Deleted(event)) if channel.id == event.channel => None,
+            (state, event) => panic!("invalid channel event {event:#?} for state {state:#?}"),
+        }
+    }
+}
+
+impl FromIterator<Event> for Option<Channel> {
+    fn from_iter<I: IntoIterator<Item = Event>>(events: I) -> Self {
+        events.into_iter().fold(None, Channel::apply)
+    }
+}
+
+impl From<&Created> for Channel {
+    fn from(event: &Created) -> Self {
+        event.channel.clone()
+    }
+}
+
+impl From<Created> for Channel {
+    fn from(event: Created) -> Self {
+        event.channel
+    }
+}