refactor so that indexer checks clock constraints

programs/clock/core/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "clock_core"
+version = "0.1.0"
+edition = "2024"
+license = { workspace = true }
+
+[lints]
+workspace = true
+
+[dependencies]
+nssa_core.workspace = true

programs/clock/core/src/lib.rs

@@ -0,0 +1,49 @@
+//! Core data structures and constants for the Clock Program.
+
+use nssa_core::{Timestamp, account::AccountId};
+
+/// The instruction type for the Clock Program. The sequencer passes the current block timestamp.
+pub type Instruction = Timestamp;
+
+pub const CLOCK_01_PROGRAM_ACCOUNT_ID: AccountId =
+    AccountId::new(*b"/LEZ/ClockProgramAccount/0000001");
+
+pub const CLOCK_10_PROGRAM_ACCOUNT_ID: AccountId =
+    AccountId::new(*b"/LEZ/ClockProgramAccount/0000010");
+
+pub const CLOCK_50_PROGRAM_ACCOUNT_ID: AccountId =
+    AccountId::new(*b"/LEZ/ClockProgramAccount/0000050");
+
+/// All clock program account ID int the order expected by the clock program
+pub const CLOCK_PROGRAM_ACCOUNT_IDS: [AccountId; 3] = [
+    CLOCK_01_PROGRAM_ACCOUNT_ID,
+    CLOCK_10_PROGRAM_ACCOUNT_ID,
+    CLOCK_50_PROGRAM_ACCOUNT_ID,
+];
+
+/// The data stored in a clock account: `[block_id: u64 LE | timestamp: u64 LE]`.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ClockAccountData {
+    pub block_id: u64,
+    pub timestamp: Timestamp,
+}
+
+impl ClockAccountData {
+    #[must_use]
+    pub fn to_bytes(self) -> [u8; 16] {
+        let mut data = [0_u8; 16];
+        data[..8].copy_from_slice(&self.block_id.to_le_bytes());
+        data[8..].copy_from_slice(&self.timestamp.to_le_bytes());
+        data
+    }
+
+    #[must_use]
+    pub fn from_bytes(bytes: &[u8; 16]) -> Self {
+        let block_id = u64::from_le_bytes(bytes[..8].try_into().unwrap());
+        let timestamp = u64::from_le_bytes(bytes[8..].try_into().unwrap());
+        Self {
+            block_id,
+            timestamp,
+        }
+    }
+}