Merge pull request #7 from rowah/add_genserver

Add genserver

lib/islands_engine/application.ex

@@ -10,6 +10,7 @@ defmodule IslandsEngine.Application do
     children = [
       # Starts a worker by calling: IslandsEngine.Worker.start_link(arg)
       # {IslandsEngine.Worker, arg}
+      {Registry, keys: :unique, name: Registry.Game}
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html

lib/islands_engine/game.ex

@@ -0,0 +1,153 @@
+defmodule IslandEngine.Game do
+  @moduledoc false
+
+  use GenServer
+
+  alias IslandsEngine.{Board, Coordinate, Guesses, Island}
+  alias IslandEngine.Rules
+
+  @players [:player1, :player2]
+
+  @spec via_tuple(String.t()) :: {:via, Registry, {Registry.Game, String.t()}}
+  def via_tuple(name), do: {:via, Registry, {Registry.Game, name}}
+
+  @spec start_link(binary()) :: {:ok, pid()} | :ignore
+  def start_link(name) when is_binary(name) do
+    case GenServer.start_link(__MODULE__, name, name: via_tuple(name)) do
+      {:ok, pid} ->
+        {:ok, pid}
+
+      {:error, {:already_started, _pid}} ->
+        :ignore
+    end
+  end
+
+  @spec init(String.t()) ::
+          {:ok,
+           %{
+             player1: %{board: map(), guesses: map(), name: String.t()},
+             player2: %{board: map(), guesses: map(), name: nil},
+             rules: %IslandEngine.Rules{
+               player1: :islands_not_set,
+               player2: :islands_not_set,
+               state: :initialized
+             }
+           }}
+  def init(name) do
+    player1 = %{name: name, board: Board.new(), guesses: Guesses.new()}
+    player2 = %{name: nil, board: Board.new(), guesses: Guesses.new()}
+    {:ok, %{player1: player1, player2: player2, rules: %Rules{}}}
+  end
+
+  @spec add_player(pid(), binary()) :: :error | {:reply, :ok, %{}}
+  def add_player(game, name) when is_binary(name), do: GenServer.call(game, {:add_player, name})
+
+  def position_island(game, player, key, row, col) when player in @players,
+    do: GenServer.call(game, {:position_island, player, key, row, col})
+
+  def set_islands(game, player) when player in @players,
+    do: GenServer.call(game, {:set_islands, player})
+
+  @spec guess_coordinate(
+          pid(),
+          String.t(),
+          integer(),
+          integer()
+        ) :: :error | {:reply, :ok, %{}}
+  def guess_coordinate(game, player, row, col),
+    do: GenServer.call(game, {:guess_coordinate, player, row, col})
+
+  def handle_call({:guess_coordinate, player_key, row, col}, _from, state_data) do
+    opponent_key = opponent(player_key)
+    opponent_board = player_board(state_data, opponent_key)
+
+    with {:ok, rules} <- Rules.check(state_data.rules, {:guess_coordinate, player_key}),
+         {:ok, coordinate} <- Coordinate.new(row, col),
+         {hit_or_miss, forested_island, win_status, opponent_board} <-
+           Board.guess(opponent_board, coordinate),
+         {:ok, rules} <- Rules.check(rules, {:win_check, win_status}) do
+      state_data
+      |> update_board(opponent_key, opponent_board)
+      |> update_guesses(player_key, hit_or_miss, coordinate)
+      |> update_rules(rules)
+      |> reply_success({hit_or_miss, forested_island, win_status})
+    else
+      :error ->
+        {:reply, :error, state_data}
+
+      {:error, :invalid_coordinate} ->
+        {:reply, {:error, :invalid_coordinate}, state_data}
+    end
+  end
+
+  def handle_call({:set_islands, player}, _from, state_data) do
+    board = player_board(state_data, player)
+
+    with {:ok, rules} <- Rules.check(state_data.rules, {:set_islands, player}),
+         true <- Board.all_islands_positioned?(board) do
+      state_data
+      |> update_rules(rules)
+      |> reply_success({:ok, board})
+    else
+      :error -> {:reply, :error, state_data}
+      false -> {:reply, {:error, :not_all_islands_positioned}, state_data}
+    end
+  end
+
+  def handle_call({:add_player, name}, _from, state_data) do
+    with {:ok, rules} <- Rules.check(state_data.rules, :add_player) do
+      state_data
+      |> update_player2_name(name)
+      |> update_rules(rules)
+      |> reply_success(:ok)
+    else
+      :error -> {:noreply, :error, state_data}
+    end
+  end
+
+  def handle_call({:position_island, player, key, row, col}, _from, state_data) do
+    board = player_board(state_data, player)
+
+    with {:ok, rules} <- Rules.check(state_data.rules, {:position_islands, player}),
+         {:ok, coordinate} <- Coordinate.new(row, col),
+         {:ok, island} <- Island.new(key, coordinate),
+         %{} = board <- Board.position_island(board, key, island) do
+      state_data
+      |> update_board(player, board)
+      |> update_rules(rules)
+      |> reply_success(:ok)
+    else
+      :error ->
+        {:reply, :error, state_data}
+
+      {:error, :invalid_coordinate} ->
+        {:reply, {:error, :invalid_coordinate}, state_data}
+
+      {:error, :invalid_island_type} ->
+        {:error, {:error, :invalid_island_type}, state_data}
+
+      {:error, :overlapping_island} ->
+        {:error, {:error, :overlapping_island}, state_data}
+    end
+  end
+
+  defp update_player2_name(state_data, name), do: put_in(state_data.player2.name, name)
+
+  defp update_rules(state_data, rules), do: %{state_data | rules: rules}
+
+  defp reply_success(state_data, reply), do: {:reply, reply, state_data}
+
+  defp update_board(state_data, player, board),
+    do: Map.update!(state_data, player, fn player -> %{player | board: board} end)
+
+  defp player_board(state_data, player), do: Map.get(state_data, player).board
+
+  defp opponent(:player1), do: :player2
+  defp opponent(:player2), do: :player1
+
+  defp update_guesses(state_data, player_key, hit_or_miss, coordinate) do
+    update_in(state_data[player_key].guesses, fn guesses ->
+      Guesses.add(guesses, hit_or_miss, coordinate)
+    end)
+  end
+end