From d11322cd8c90f677785d15ff5c51f493f4decf55 Mon Sep 17 00:00:00 2001
From: mrkaspa <michel.ingesoft@gmail.com>
Date: Thu, 12 May 2016 15:53:09 -0500
Subject: [PATCH] Building the graph in progress

---
 lib/exstreme/gnode/behaviour.ex | 40 ++++++++++++++++++++++++
 lib/exstreme/gnode/broadcast.ex |  7 +++++
 lib/exstreme/gnode/common.ex    |  8 +++++
 lib/exstreme/gnode/funnel.ex    |  7 +++++
 lib/exstreme/graph.ex           |  2 +-
 lib/exstreme/graph_builder.ex   | 55 +++++++++++++++++++++++++++++++++
 6 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 lib/exstreme/gnode/behaviour.ex
 create mode 100644 lib/exstreme/gnode/broadcast.ex
 create mode 100644 lib/exstreme/gnode/common.ex
 create mode 100644 lib/exstreme/gnode/funnel.ex
 create mode 100644 lib/exstreme/graph_builder.ex

diff --git a/lib/exstreme/gnode/behaviour.ex b/lib/exstreme/gnode/behaviour.ex
new file mode 100644
index 0000000..9313e68
--- /dev/null
+++ b/lib/exstreme/gnode/behaviour.ex
@@ -0,0 +1,40 @@
+defmodule Exstreme.Gnode.Behaviour do
+  @moduledoc """
+  """
+
+  defmodule Data do
+    @moduledoc """
+    """
+    alias __MODULE__
+
+    @type t :: %Data{next: [pid], pid: pid, func: (term) -> no_return, opts: [key: term]}
+    defstruct [next: [], pid: nil, func: nil, opts: []]
+  end
+
+  def __using__ do
+    quote do
+      use GenServer
+      alias Exstreme.Gnode.Behaviour.Data
+
+      def start_link(opts \\ []) do
+        GenServer.start_link(__MODULE__, :ok, opts)
+      end
+
+      def init(params = [func: func]) do
+        opts = Keyword.drop(params, [:func, :type])
+        {:ok, %Data{func: func, pid: self, opts: opts}}
+      end
+
+      def handle_cast({:connect, to_pid}, data) do
+        new_data = update_in(data.next, fn(next) -> [pid | next] end)
+        {:noreply, new_data}
+      end
+
+      def send_next(next, msg) do
+        Enum.each(next, fn(pid) ->
+          GenServer.cast(pid, msg)
+        do)
+      end
+    end
+  end
+end
diff --git a/lib/exstreme/gnode/broadcast.ex b/lib/exstreme/gnode/broadcast.ex
new file mode 100644
index 0000000..6bb557e
--- /dev/null
+++ b/lib/exstreme/gnode/broadcast.ex
@@ -0,0 +1,7 @@
+defmodule Exstreme.GNode.Broadcast do
+  use Exstreme.GNode.Behaviour
+
+  def handle_cast({:next, {_, msg}}, stats) do
+    send_next(stats.next, msg)
+  end
+end
diff --git a/lib/exstreme/gnode/common.ex b/lib/exstreme/gnode/common.ex
new file mode 100644
index 0000000..6d91b67
--- /dev/null
+++ b/lib/exstreme/gnode/common.ex
@@ -0,0 +1,8 @@
+defmodule Exstreme.GNode.Common do
+  use Exstreme.GNode.Behaviour
+
+  def handle_cast({:next, {_, msg} }, stats) do
+    {:ok, result} = stats.func.(msg)
+    send_next(stats.next, result)
+  end
+end
diff --git a/lib/exstreme/gnode/funnel.ex b/lib/exstreme/gnode/funnel.ex
new file mode 100644
index 0000000..38ddfc1
--- /dev/null
+++ b/lib/exstreme/gnode/funnel.ex
@@ -0,0 +1,7 @@
+defmodule Exstreme.GNode.Funnel do
+  use Exstreme.GNode.Behaviour
+
+  def handle_cast({:next, {from_data, msg}}, stats) do
+  end
+
+end
diff --git a/lib/exstreme/graph.ex b/lib/exstreme/graph.ex
index 48cec9c..29437fb 100644
--- a/lib/exstreme/graph.ex
+++ b/lib/exstreme/graph.ex
@@ -3,7 +3,7 @@ defmodule Exstreme.Graph do
   """
   alias __MODULE__
 
-  @type t :: %Graph{params: [key: term], nodes: %{key: atom}, connections: %{key: atom}}
+  @type t :: %Graph{params: [key: term], nodes: %{key: [key: term]}, connections: %{key: atom}}
   defstruct params: [], nodes: %{}, connections: %{}
 
   @doc """
diff --git a/lib/exstreme/graph_builder.ex b/lib/exstreme/graph_builder.ex
new file mode 100644
index 0000000..b982e11
--- /dev/null
+++ b/lib/exstreme/graph_builder.ex
@@ -0,0 +1,55 @@
+defmodule Exstreme.GraphBuilder do
+  @moduledoc """
+  """
+  alias Exstreme.GNode.Broadcast
+  alias Exstreme.GNode.Funnel
+  alias Exstreme.GNode.Common
+
+  @doc """
+  """
+  @spec build(Graph.t) :: Graph.t
+  def build(graph) do
+    new_graph = update_in(graph.nodes, &start_nodes/1)
+    connect_nodes(new_graph)
+    new_graph
+  end
+
+  #private
+
+  @spec start_nodes(%{key: [key: term]}) :: %{key: [key: term]}
+  defp start_nodes(nodes) do
+    nodes
+    |> Enum.map(&start_node/1)
+    |> Map.new
+  end
+
+  @spec start_node({atom, [key: any]}) :: {atom, [key: any]}
+  defp start_node({node, params = [type: type]}) do
+    {:ok, pid} =
+      case type do
+        :broadcast -> Broadcast.start_link(params)
+        :funnel -> Funnel.start_link(params)
+        _ -> Common.start_link(params)
+      end
+    {node, Keyword.put(params, :pid, pid)}
+  end
+
+  @spec connect_nodes(Graph.t) :: no_return
+  defp connect_nodes(%Graph{nodes: nodes, connections: connections}) do
+    Enum.each(connections, &connect_pair/1)
+  end
+
+  @spec connect_pair({atom, [atom]}) :: no_return
+  defp connect_pair({from, to}) when is_list(to) do
+    Enum.map(1..Enum.count(to), fn(_) -> from end)
+    |> Enum.zip(to)
+    |> Enum.each(&connect_pair/1)
+  end
+
+  @spec connect_pair({atom, atom}) :: no_return
+  defp connect_pair({from, to}) when is_atom(to) do
+    [pid: pid_from] = nodes[from]
+    [pid: pid_to] = nodes[to]
+    GenServer.cast(pid_from, {:connect, pid_to})
+  end
+end