From 073e3529e9f7066f6aede86aa49f0905ee395916 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Sat, 20 Oct 2018 16:34:08 +1100
Subject: [PATCH] Add half-finished chain code

---
 Cargo.toml                    |  1 +
 beacon_chain/chain/Cargo.toml |  9 +++++
 beacon_chain/chain/src/lib.rs | 67 +++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 beacon_chain/chain/Cargo.toml
 create mode 100644 beacon_chain/chain/src/lib.rs

diff --git a/Cargo.toml b/Cargo.toml
index 0ac7299298..57f0feb472 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,6 +32,7 @@ name = "lighthouse"
 
 [workspace]
 members = [
+	"beacon_chain/chain",
 	"beacon_chain/types",
 	"beacon_chain/utils/bls",
 	"beacon_chain/utils/boolean-bitfield",
diff --git a/beacon_chain/chain/Cargo.toml b/beacon_chain/chain/Cargo.toml
new file mode 100644
index 0000000000..ab328dc268
--- /dev/null
+++ b/beacon_chain/chain/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "chain"
+version = "0.1.0"
+authors = ["Paul Hauner <paul@paulhauner.com>"]
+
+[dependencies]
+types = { path = "../types" }
+validator_induction = { path = "../validator_induction" }
+validator_shuffling = { path = "../validator_shuffling" }
diff --git a/beacon_chain/chain/src/lib.rs b/beacon_chain/chain/src/lib.rs
new file mode 100644
index 0000000000..cff48c986e
--- /dev/null
+++ b/beacon_chain/chain/src/lib.rs
@@ -0,0 +1,67 @@
+extern crate types;
+extern crate validator_induction;
+extern crate validator_shuffling;
+
+use types::{
+    ActiveState,
+    ChainConfig,
+    CrystallizedState,
+    ValidatorRecord,
+};
+use validator_induction::{
+    ValidatorInductor,
+    ValidatorRegistration,
+};
+use validator_shuffling::shard_and_committees_for_cycle;
+
+pub struct ChainHead<'a> {
+    act_state: ActiveState,
+    cry_state: &'a CrystallizedState,
+    config: ChainConfig,
+}
+
+impl<'a> ChainHead<'a> {
+    pub fn genesis(
+        initial_validator_entries: &[ValidatorRegistration],
+        config: ChainConfig)
+        -> Self
+    {
+        /*
+         * Parse the ValidatorRegistrations into ValidatorRecords and induct them.
+         *
+         * Ignore any records which fail proof-of-possession or are invalid.
+         */
+        let validators = {
+            let mut validators = vec![];
+            let inductor = ValidatorInductor {
+                current_slot: 0,
+                shard_count: config.shard_count,
+                validators: &mut validators,
+                empty_validator_start: 0,
+            };
+            for registration in initial_validator_entries {
+                let _ = inductor.induct(&registration);
+            };
+            validators
+        };
+
+        /*
+         * Delegate the validators to shards.
+         */
+        let shard_and_committees = shard_and_committees_for_cycle(
+            &vec![0; 32],
+            &validators,
+            0,
+            &config);
+
+        //TODO: complete this
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}