From 4d4e3fb57584d9c3bba6b4fc488f23db4937ae79 Mon Sep 17 00:00:00 2001
From: Alex Stokes <r.alex.stokes@gmail.com>
Date: Sun, 20 Aug 2023 09:31:05 -0600
Subject: [PATCH] refactor how a user can get a `Clock` for the configured
 network

---
 ethereum-consensus/src/lib.rs                 |  1 +
 ethereum-consensus/src/networks.rs            |  8 ++++++++
 .../src/state_transition/context.rs           | 20 +++++++++----------
 3 files changed, 18 insertions(+), 11 deletions(-)
 create mode 100644 ethereum-consensus/src/networks.rs

diff --git a/ethereum-consensus/src/lib.rs b/ethereum-consensus/src/lib.rs
index e1121c358..0b3471424 100644
--- a/ethereum-consensus/src/lib.rs
+++ b/ethereum-consensus/src/lib.rs
@@ -9,6 +9,7 @@ pub mod deneb;
 pub mod domains;
 pub mod kzg;
 pub mod networking;
+pub mod networks;
 pub mod phase0;
 pub mod primitives;
 #[cfg(feature = "serde")]
diff --git a/ethereum-consensus/src/networks.rs b/ethereum-consensus/src/networks.rs
new file mode 100644
index 000000000..bb057c642
--- /dev/null
+++ b/ethereum-consensus/src/networks.rs
@@ -0,0 +1,8 @@
+/// This module contains support for various Ethereum netowrks.
+use crate::state_transition::Context;
+
+// NOTE: the default genesis time here is usually seen on testnets
+// where we have control over the genesis details
+pub fn typical_genesis_time(context: &Context) -> u64 {
+    context.min_genesis_time + context.genesis_delay
+}
diff --git a/ethereum-consensus/src/state_transition/context.rs b/ethereum-consensus/src/state_transition/context.rs
index c228adf08..db2db2cf9 100644
--- a/ethereum-consensus/src/state_transition/context.rs
+++ b/ethereum-consensus/src/state_transition/context.rs
@@ -286,18 +286,16 @@ impl Context {
         }
     }
 
-    pub fn clock(&self, genesis_time: Option<u64>) -> Clock<SystemTimeProvider> {
+    pub fn clock(&self) -> Option<Clock<SystemTimeProvider>> {
         match self.name.as_ref() {
-            "mainnet" => clock::for_mainnet(),
-            "sepolia" => clock::for_sepolia(),
-            "goerli" => clock::for_goerli(),
-            _ => {
-                // NOTE: the default genesis time here is usually seen on testnets
-                // where we have control over the genesis details
-                let genesis_time =
-                    genesis_time.unwrap_or(self.min_genesis_time + self.genesis_delay);
-                clock::from_system_time(genesis_time, self.seconds_per_slot, self.slots_per_epoch)
-            }
+            "mainnet" => Some(clock::for_mainnet()),
+            "sepolia" => Some(clock::for_sepolia()),
+            "goerli" => Some(clock::for_goerli()),
+            _ => None,
         }
     }
+
+    pub fn clock_at(&self, genesis_time: u64) -> Clock<SystemTimeProvider> {
+        clock::from_system_time(genesis_time, self.seconds_per_slot, self.slots_per_epoch)
+    }
 }