From 0d68eeabfb953e9976504c8d27ed08c17208cc02 Mon Sep 17 00:00:00 2001
From: Dan Barber <github@danbarber.me>
Date: Sun, 11 Mar 2018 13:11:38 -0400
Subject: [PATCH] Move everything to websockets

---
 assets/js/app.js                       | 24 +++++++----
 assets/js/services/channel.js          |  5 ---
 lib/chess/store/game.ex                |  8 +++-
 lib/chess_web/channels/game_channel.ex | 60 +++++++++++++++++++++++---
 lib/chess_web/channels/user_socket.ex  |  2 +-
 5 files changed, 77 insertions(+), 22 deletions(-)

diff --git a/assets/js/app.js b/assets/js/app.js
index eb19fa5..3605b72 100644
--- a/assets/js/app.js
+++ b/assets/js/app.js
@@ -25,28 +25,34 @@ class App extends React.Component {
 
     store.dispatch(setGameId(gameId));
 
-    API.getGame(gameId)
-      .then(response => {
-        store.dispatch(setPlayer(response.data.player));
-        store.dispatch(setGame(response.data));
-      });
-
     this.channel = Channel.gameChannel(gameId);
 
-    this.channel.on("game_update", data => {
+    this.channel.on("game:update", data => {
+      if (data.player != undefined) {
+        store.dispatch(setPlayer(data.player));
+      };
       store.dispatch(setGame(data));
     });
+
+    this.channel.join()
+      .receive("error", resp => {
+        console.log("Unable to join", resp);
+      });
   }
 
   sendMove(gameId, move) {
-    API.updateGame(gameId, move);
+    this.channel.push("game:move", move);
   }
 
   render() {
     const { store, gameId } = this.props;
 
     return (
-      <ChessBoard gameId={gameId} store={store} sendMove={this.sendMove} />
+      <ChessBoard
+        gameId={gameId}
+        store={store}
+        sendMove={this.sendMove.bind(this)}
+      />
     );
   }
 }
diff --git a/assets/js/services/channel.js b/assets/js/services/channel.js
index ac8eed4..1313eeb 100644
--- a/assets/js/services/channel.js
+++ b/assets/js/services/channel.js
@@ -4,11 +4,6 @@ const Channel = {
   gameChannel: (gameId) => {
     const channel = socket.channel(`game:${gameId}`, {});
 
-    channel.join()
-      .receive("error", resp => {
-        console.log("Unable to join", resp);
-      });
-
     return channel;
   },
 };
diff --git a/lib/chess/store/game.ex b/lib/chess/store/game.ex
index 1f62af8..2f5387d 100644
--- a/lib/chess/store/game.ex
+++ b/lib/chess/store/game.ex
@@ -32,9 +32,13 @@ defmodule Chess.Store.Game do
   def change_turn("white"), do: "black"
 
   def for_user(user) do
+    for_user_id(user.id)
+  end
+
+  def for_user_id(user_id) do
     from game in Game,
-      where: game.user_id == ^user.id,
-      or_where: game.opponent_id == ^user.id
+      where: game.user_id == ^user_id,
+      or_where: game.opponent_id == ^user_id
   end
 
   def ordered(query) do
diff --git a/lib/chess_web/channels/game_channel.ex b/lib/chess_web/channels/game_channel.ex
index b9f7fdf..51970b1 100644
--- a/lib/chess_web/channels/game_channel.ex
+++ b/lib/chess_web/channels/game_channel.ex
@@ -1,19 +1,69 @@
 defmodule ChessWeb.GameChannel do
   @moduledoc false
 
-  use Phoenix.Channel
+  use ChessWeb, :channel
 
+  alias Chess.Store.Game
   alias Chess.Board
 
-  def join("game:" <> _game_id, _params, socket) do
-    {:ok, socket}
+  import Chess.Auth, only: [current_user: 1]
+
+  def join("game:" <> game_id, _params, socket) do
+    send(self, {:after_join, game_id})
+
+    {:ok, assign(socket, :game_id, game_id)}
   end
 
-  def update_game(game) do
+  def handle_info({:after_join, game_id}, socket) do
+    game =
+      socket.assigns.current_user_id
+      |> Game.for_user_id()
+      |> Repo.get!(game_id)
+
+    payload = %{
+      player: player(socket, game),
+      board: Board.transform(game.board),
+      turn: game.turn
+    }
+    push(socket, "game:update", payload)
+
+    {:noreply, socket}
+  end
+
+  def handle_in("game:move", move_params, socket) do
+    game =
+      socket.assigns.current_user_id
+      |> Game.for_user_id()
+      |> Repo.get!(socket.assigns.game_id)
+
+    changeset = Game.changeset(
+      game, %{
+        board: Board.move_piece(game.board, move_params),
+        turn: Game.change_turn(game.turn)
+      }
+    )
+
+    case Repo.update(changeset) do
+      {:ok, game} ->
+        send_update(game)
+
+        {:noreply, socket}
+    end
+  end
+
+  def send_update(game) do
     payload = %{
       board: Board.transform(game.board),
       turn: game.turn
     }
-    ChessWeb.Endpoint.broadcast("game:#{game.id}", "game_update", payload)
+    ChessWeb.Endpoint.broadcast("game:#{game.id}", "game:update", payload)
+  end
+
+  defp player(socket, game) do
+    if game.user_id == socket.assigns.current_user_id do
+      "white"
+    else
+      "black"
+    end
   end
 end
diff --git a/lib/chess_web/channels/user_socket.ex b/lib/chess_web/channels/user_socket.ex
index cc9378e..d6c27ab 100644
--- a/lib/chess_web/channels/user_socket.ex
+++ b/lib/chess_web/channels/user_socket.ex
@@ -24,7 +24,7 @@ defmodule ChessWeb.UserSocket do
   def connect(%{"token" => token}, socket) do
     case Token.verify(socket, "game socket", token, max_age: 1_209_600) do
       {:ok, user_id} ->
-        {:ok, assign(socket, :current_user, user_id)}
+        {:ok, assign(socket, :current_user_id, user_id)}
       {:error, _reason} ->
         :error
     end