Signing and stuff

1 files changed, 113 insertions, 0 deletions

diff --git a/shard/lib/app/identity.ex b/shard/lib/app/identity.ex
new file mode 100644
index 0000000..7e97897
--- /dev/null
+++ b/shard/lib/app/identity.ex
@@ -0,0 +1,113 @@
+defmodule SApp.Identity do
+  use GenServer
+
+  require Logger
+
+  defmodule Manifest do
+    defstruct [:pk]
+  end
+
+  defmodule State do
+    defstruct [:info, :rev, :signed]
+  end
+
+  defimpl Shard.Manifest, for: Manifest do
+    def start(m) do
+      DynamicSupervisor.start_child(Shard.DynamicSupervisor, {SApp.Identity, m.pk})
+    end
+  end
+
+  def start_link(pk) do
+    GenServer.start_link(__MODULE__, pk)
+  end
+
+  def init(pk) do
+    manifest = %Manifest{pk: pk}
+    id = SData.term_hash manifest
+
+    case Shard.Manager.register(id, manifest, self()) do
+      :ok ->
+        Shard.Manager.dispatch_to(id, nil, self())
+        state = case Shard.Manager.load_state(id) do
+          nil ->
+            info = %{nick: default_nick(pk)}
+            SData.SignRev.new info
+          st ->
+            st
+        end
+        GenServer.cast(self(), :init_pull)
+        {:ok, %{pk: pk, id: id, state: state}}
+      :redundant ->
+        exit(:redundant)
+    end
+  end
+
+  def default_nick(pk) do
+    nick_suffix = pk
+                  |> binary_part(0, 4)
+                  |> Base.encode16
+                  |> String.downcase
+    "Anon" <> nick_suffix
+  end
+
+  def find_proc(pk) do
+    manifest = %Manifest{pk: pk}
+    id = SData.term_hash manifest
+    Shard.Manager.find_proc id
+  end
+
+  def handle_call(:manifest, _from, state) do
+    {:replyl, state.manifest, state}
+  end
+
+  def handle_call(:get_info, _from, state) do
+    {:reply, SData.SignRev.get(state.state), state}
+  end
+
+  def handle_call({:set_info, new_info}, _from, state) do
+    case SData.SignRev.set(state.state, new_info, state.pk) do
+      {:ok, st2} ->
+        Shard.Manager.save_state(state.id, st2)
+        state = put_in(state.state, st2)
+        bcast_state(state)
+        {:reply, :ok, state}
+      err ->
+        {:reply, err, state}
+    end
+  end
+
+  def handle_cast(:init_pull, state) do
+    for {_, pid, _, _} <- Shard.Manager.list_peers do
+      GenServer.cast(pid, {:send_msg, {:interested, [state.id]}})
+    end
+    {:noreply, state}
+  end
+
+  def handle_cast({:interested, peer_id}, state) do
+    Shard.Manager.send(peer_id, {state.id, nil, {:update, SData.SignRev.signed(state.state)}})
+  end
+
+  def handle_cast({:msg, peer_id, _shard_id, nil, msg}, state) do
+    state = case msg do
+      {:update, signed} ->
+        case SData.SignRev.merge(state.state, signed, state.pk) do
+          {true, st2} ->
+            Shard.Manager.save_state(state.id, st2)
+            state = put_in(state.state, st2)
+            bcast_state(state, [peer_id])
+            state
+          {false, _} ->
+            state
+        end
+    end
+    {:noreply, state}
+  end
+
+  def bcast_state(state, exclude \\ []) do
+    for peer_id <- Shard.Manager.get_shard_peers(state.id) do
+      if not Enum.member? exclude, peer_id do
+        Shard.Manager.send(peer_id, {state.id, nil, {:update, SData.SignRev.signed(state.state)}})
+      end
+    end
+  end
+end