Refactor out external parts to generics

Also creates a dedicated file for the message log.

substrate/tendermint/src/ext.rs

@@ -0,0 +1,28 @@
+use core::{hash::Hash, fmt::Debug};
+
+pub trait ValidatorId: Clone + Copy + PartialEq + Eq + Hash + Debug {}
+impl<V: Clone + Copy + PartialEq + Eq + Hash + Debug> ValidatorId for V {}
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum BlockError {
+  // Invalid behavior entirely
+  Fatal,
+  // Potentially valid behavior dependent on unsynchronized state
+  Temporal,
+}
+
+pub trait Block: Clone + PartialEq {
+  type Id: Copy + Clone + PartialEq;
+
+  fn id(&self) -> Self::Id;
+}
+
+pub trait Network<V: ValidatorId, B: Block> {
+  fn total_weight(&self) -> u64;
+  fn weight(&self, validator: V) -> u64;
+  fn threshold(&self) -> u64 {
+    ((self.total_weight() * 2) / 3) + 1
+  }
+
+  fn validate(&mut self, block: B) -> Result<(), BlockError>;
+}