1 files changed, 46 insertions, 0 deletions
diff --git a/lib/manager.ex b/lib/manager.ex
new file mode 100644
index 0000000..ce11117
--- /dev/null
+++ b/lib/manager.ex
@@ -0,0 +1,46 @@
+defmodule Shard.Manager do
+  use GenServer
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
+  end
+
+  def init(_) do
+    state = %{
+              shards: %{}
+            }
+    {:ok, state}
+  end
+
+  def handle_call({:find, shard_id}, _from, state) do
+    {:reply, state.shards[shard_id], state}
+  end
+
+  def handle_call(:list, _from, state) do
+    {:reply, Map.to_list(state.shards), state}
+  end
+
+  def handle_cast({:register, shard_id, pid}, state) do
+    if Map.has_key?(state.shards, shard_id) do
+      GenServer.cast(pid, {:redundant, shard_id})
+      state
+    else
+      new_shards = Map.put(state.shards, shard_id, pid)
+      {:noreply, %{ state | shards: new_shards }}
+    end
+  end
+
+  def handle_cast({:interested, peer_id, peer_pid, shards}, state) do
+    shards
+    |> Enum.filter(&(Map.has_key?(state.shards, &1)))
+    |> Enum.each(&(GenServer.cast(state.shards[&1], {:interested, peer_id, peer_pid})))
+    {:noreply, state}
+  end
+
+  def handle_cast({:dispatch, peer_id, peer_pid, shard, msg}, state) do
+    if Map.has_key?(state.shards, shard) do
+      GenServer.cast(state.shards[shard], {:msg, peer_id, peer_pid, msg})
+    end
+    {:noreply, state}
+  end
+end