Provide a view of logins to clients.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/login/history.rs b/src/login/history.rs
new file mode 100644
index 0000000..add7d1e
--- /dev/null
+++ b/src/login/history.rs
@@ -0,0 +1,47 @@
+use super::{
+    event::{Created, Event},
+    Id, Login,
+};
+use crate::event::{Instant, ResumePoint, Sequence};
+
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct History {
+    pub login: Login,
+    pub created: Instant,
+}
+
+// State interface
+impl History {
+    pub fn id(&self) -> &Id {
+        &self.login.id
+    }
+
+    // Snapshot of this login as it was when created. (Note to the future: it's okay
+    // if this returns a redacted or modified version of the login. If we  implement
+    // renames by redacting the original name, then this should return the edited login, not the original, even if that's not how it was "as created.")
+    #[cfg(test)]
+    pub fn as_created(&self) -> Login {
+        self.login.clone()
+    }
+
+    pub fn as_of(&self, resume_point: impl Into<ResumePoint>) -> Option<Login> {
+        self.events()
+            .filter(Sequence::up_to(resume_point.into()))
+            .collect()
+    }
+}
+
+// Events interface
+impl History {
+    fn created(&self) -> Event {
+        Created {
+            instant: self.created,
+            login: self.login.clone(),
+        }
+        .into()
+    }
+
+    pub fn events(&self) -> impl Iterator<Item = Event> {
+        [self.created()].into_iter()
+    }
+}