1 files changed, 355 insertions, 0 deletions
diff --git a/presentation/tic_tac_toe.exs b/presentation/tic_tac_toe.exs
new file mode 100644
index 0000000..e05bed4
--- /dev/null
+++ b/presentation/tic_tac_toe.exs
@@ -0,0 +1,355 @@
+defmodule Generator do
+  def gen_reference() do
+    min = String.to_integer("100000", 36)
+    max = String.to_integer("ZZZZZZ", 36)
+
+    max
+    |> Kernel.-(min)
+    |> :rand.uniform()
+    |> Kernel.+(min)
+    |> Integer.to_string(36)
+  end
+end
+
+defmodule TicTacToe.GameManager do
+  use GenServer
+
+  defmodule State do
+    defstruct games: %{},
+              joinable_games: [],
+              player_games: %{}
+  end
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, %{
+      pid: nil
+    })
+  end
+
+  def init(_) do
+    {:ok, %State{}}
+  end
+
+  defp create_board(), do: Enum.map(0..2, fn _ -> Enum.map(0..2, fn _ -> :empty end) end)
+
+  defp create_game(game_id, player) do
+    %{
+      x: player,
+      o: nil,
+      board: create_board()
+    }
+  end
+
+  def handle_info(
+        {:join, %{client_pid: client_pid, username: username, player_id: connection_id} = player},
+        %State{player_games: player_games, games: games, joinable_games: joinable_games} = state
+      ) do
+    if length(joinable_games) == 0 do
+      game_id = Generator.gen_reference()
+      send(client_pid, {:join_game, game_id})
+
+      {:ok,
+       %State{
+         state
+         | games: Map.put(games, game_id, create_game(game_id, player)),
+           joinable_games: joinable_games ++ [game_id],
+           player_games: Map.put(player_games, player_id, game_id)
+       }}
+    else
+      [joining_game_id | rest] = joinable_games
+      game = Map.get(games, joining_game_id)
+      send(game.x.client_pid, :player_joined)
+      send(client_pid, {:join_game, game_id})
+
+      {:ok,
+       %State{
+         state
+         | games: Map.put(games, game_id, %{game | o: player}),
+           joinable_games: rest,
+           connection_games: Map.put(player_games, connection_id, game_id)
+       }}
+    end
+  end
+end
+
+defmodule TicTacToe.SSHDaemon do
+  @port 4000
+  @key_dir "/tmp/keys"
+  use GenServer
+  require Logger
+
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, %{
+      pid: nil
+    })
+  end
+
+  def init(state) do
+    send(self(), :start)
+
+    {:ok, state}
+  end
+
+  def handle_info(:start, state) do
+    game_manager_pid =
+      case GenServer.start_link(TicTacToe.GameManager, [%{}]) do
+        {:ok, game_manager_pid} ->
+          game_manager_pid
+
+        _ ->
+          nil
+      end
+
+    case :ssh.daemon(
+           @port,
+           system_dir: @key_dir,
+           ssh_cli:
+             {TicTacToe.SSHListener,
+              [
+                %TicTacToe.SSHListener.State{
+                  game_manager_pid: game_manager_pid
+                }
+              ]},
+           disconnectfun: &on_disconnect/1,
+           id_string: :random,
+           parallel_login: true,
+           max_sessions: 1_000,
+           subsystems: [],
+           no_auth_needed: true
+         ) do
+      {:ok, pid} ->
+        Logger.info("SSH server started on port #{port}, on #{inspect(pid)}")
+
+        Process.link(pid)
+
+        {:noreply, %{state | pid: pid, game_manager_pid: game_manager_pid}, :hibernate}
+
+      {:error, err} ->
+        raise inspect(err)
+    end
+
+    {:noreply, state}
+  end
+
+  def handle_info(_, state), do: {:noreply, state}
+
+  defp on_disconnect(_reason) do
+    Logger.info("#{inspect(self())} disconnected")
+  end
+end
+
+defmodule TicTacToe.SSHListener do
+  alias Chessh.SSH.Client
+
+  alias IO.ANSI
+
+  require Logger
+
+  @behaviour :ssh_server_channel
+  @session_closed_message [
+    ANSI.clear(),
+    ["This session has been closed"]
+  ]
+
+  defmodule State do
+    defstruct channel_id: nil,
+              client_pid: nil,
+              game_manager_pid: nil,
+              connection_ref: nil
+  end
+
+  def init([%State{} = init_state]) do
+    {:ok, init_state}
+  end
+
+  def handle_msg({:ssh_channel_up, channel_id, connection_ref}, %State{} = state) do
+    Logger.debug("SSH channel up #{inspect(:ssh.connection_info(connection_ref))}")
+
+    username =
+      :ssh.connection_info(connection_ref)
+      |> Keyword.fetch!(:user)
+      |> String.Chars.to_string()
+
+    {:ok,
+     %State{
+       state
+       | channel_id: channel_id,
+         connection_ref: connection_ref,
+         player: %{
+           id: Generator.gen_reference(),
+           username: username
+         }
+     }}
+  end
+
+  def handle_msg(
+        {:EXIT, client_pid, _reason},
+        %State{client_pid: client_pid, channel_id: channel_id} = state
+      ) do
+    send(client_pid, :quit)
+    {:stop, channel_id, state}
+  end
+
+  def handle_msg(
+        {:send_data, data},
+        %State{connection_ref: connection_ref, channel_id: channel_id} = state
+      ) do
+    :ssh_connection.send(connection_ref, channel_id, data)
+    {:ok, state}
+  end
+
+  def handle_msg(
+        :session_closed,
+        %State{connection_ref: connection_ref, channel_id: channel_id} = state
+      ) do
+    :ssh_connection.send(connection_ref, channel_id, @session_closed_message)
+    {:stop, channel_id, state}
+  end
+
+  def handle_msg(msg, term) do
+    Logger.debug("Unknown msg #{inspect(msg)}, #{inspect(term)}")
+  end
+
+  def handle_ssh_msg(
+        {:ssh_cm, _connection_handler, {:data, _channel_id, _type, data}},
+        %State{client_pid: client_pid} = state
+      ) do
+    send(client_pid, {:data, data})
+    {:ok, state}
+  end
+
+  def handle_ssh_msg(
+        {:ssh_cm, connection_handler,
+         {:pty, channel_id, want_reply?, {_term, _width, _height, _pixwidth, _pixheight, _opts}}},
+        %State{} = state
+      ) do
+    Logger.debug("#{inspect(state.player_session)} has requested a PTY")
+    :ssh_connection.reply_request(connection_handler, want_reply?, :success, channel_id)
+    {:ok, state}
+  end
+
+  def handle_ssh_msg(
+        {:ssh_cm, connection_handler, {:env, channel_id, want_reply?, var, value}},
+        state
+      ) do
+    :ssh_connection.reply_request(connection_handler, want_reply?, :failure, channel_id)
+
+    {:ok, state}
+  end
+
+  def handle_ssh_msg(
+        {:ssh_cm, _connection_handler,
+         {:window_change, _channel_id, _width, _height, _pixwidth, _pixheight}},
+        %State{client_pid: client_pid} = state
+      ) do
+    {:ok, state}
+  end
+
+  def handle_ssh_msg(
+        {:ssh_cm, connection_handler, {:shell, channel_id, want_reply?}},
+        %State{player: player} = state
+      ) do
+    :ssh_connection.reply_request(connection_handler, want_reply?, :success, channel_id)
+
+    {:ok, client_pid} =
+      GenServer.start_link(Client, [
+        %Client.State{
+          tui_pid: self(),
+          player: player
+        }
+      ])
+
+    send(client_pid, :refresh)
+    {:ok, %State{state | client_pid: client_pid}}
+  end
+
+  def handle_ssh_msg(
+        msg,
+        %State{channel_id: channel_id} = state
+      ) do
+    Logger.debug("UNKOWN MESSAGE #{inspect(msg)}")
+    # {:stop, channel_id, state}
+    {:ok, state}
+  end
+
+  def terminate(_reason, _state) do
+    :ok
+  end
+end
+
+defmodule TicTacToe.Client do
+  alias IO.ANSI
+  use GenServer
+
+  @clear_codes [
+    ANSI.clear(),
+    ANSI.home()
+  ]
+
+  defmodule State do
+    defstruct tui_pid: nil,
+              game_manager_pid: nil,
+              player: %{},
+              game_id: nil
+  end
+
+  @impl true
+  def init([%State{game_manager_pid: game_manager_pid, player: player} = state]) do
+    player = %{
+      player
+      | client_pid: self()
+    }
+
+    send(game_manager_pid, {:join, player})
+
+    {:ok,
+     %State{
+       player: player
+     }}
+  end
+
+  @impl true
+  def handle_info(:quit, %State{} = state) do
+    {:stop, :normal, state}
+  end
+
+  @impl true
+  def handle_info({:join_game, game_id}, %State{} = state) do
+    state = %State{state | game_id: game_id}
+    render(state)
+    {:stop, :normal, state}
+  end
+
+  def handle(
+        {:data, data},
+        %State{} = state
+      ) do
+    case keymap(data) do
+      :quit ->
+        {:stop, :normal, state}
+    end
+  end
+
+  def handle(
+        :player_joined,
+        %State{} = state
+      ) do
+    render(state)
+    {:noreply, state}
+  end
+
+  defp render(%State{
+         tui_pid: tui_pid
+       }) do
+    send(tui_pid, {:send_data, ["Testing"]})
+  end
+
+  def keymap(key) do
+    case key do
+      # Exit keys - C-c and C-d
+      <<3>> -> :quit
+      <<4>> -> :quit
+      x -> x
+    end
+  end
+end