defmodule Agarex.Game.Server do
  alias Agarex.Game.State
  use GenServer
 
  @fps 30
  @tick_ms div(1000, @fps)
 
  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
  end
 
  @impl true
  def init(_) do
    Process.send_after(self(), :tick, @tick_ms)
    {:ok, %{time: System.monotonic_time(), game_state: State.new()}}
  end
 
  # ...
 
  @impl true
  def handle_info(:tick, state) do
    Process.send_after(self(), :tick, @tick_ms)
    state = tick(state)
    {:noreply, state}
  end
 
 
  defp tick(state) do
    new_time = System.monotonic_time()
    delta_time = new_time - state.time
 
    game_state = State.tick(state.game_state, delta_time)
    Phoenix.PubSub.broadcast(Agarex.PubSub, "game/tick", {"game/tick", game_state})
 
    %{state | time: new_time, game_state: game_state}
  end
end
defmodule Agarex.Game.Server do
  alias Agarex.Game.State
  use GenServer
 
  @fps 30
  @tick_ms div(1000, @fps)
 
  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
  end
 
  @impl true
  def init(_) do
    Process.send_after(self(), :tick, @tick_ms)
    {:ok, %{time: System.monotonic_time(), game_state: State.new()}}
  end
 
  # ...
 
  @impl true
  def handle_info(:tick, state) do
    Process.send_after(self(), :tick, @tick_ms)
    state = tick(state)
    {:noreply, state}
  end
 
 
  defp tick(state) do
    new_time = System.monotonic_time()
    delta_time = new_time - state.time
 
    game_state = State.tick(state.game_state, delta_time)
    Phoenix.PubSub.broadcast(Agarex.PubSub, "game/tick", {"game/tick", game_state})
 
    %{state | time: new_time, game_state: game_state}
  end
end
defmodule Agarex.Game.Server do
  alias Agarex.Game.State
  use GenServer
 
  @fps 30
  @tick_ms div(1000, @fps)
 
  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
  end
 
  @impl true
  def init(_) do
    Process.send_after(self(), :tick, @tick_ms)
    {:ok, %{time: System.monotonic_time(), game_state: State.new()}}
  end
 
  # ...
 
  @impl true
  def handle_info(:tick, state) do
    Process.send_after(self(), :tick, @tick_ms)
    state = tick(state)
    {:noreply, state}
  end
 
 
  defp tick(state) do
    new_time = System.monotonic_time()
    delta_time = new_time - state.time
 
    game_state = State.tick(state.game_state, delta_time)
    Phoenix.PubSub.broadcast(Agarex.PubSub, "game/tick", {"game/tick", game_state})
 
    %{state | time: new_time, game_state: game_state}
  end
end
defmodule Agarex.Game.Server do
  alias Agarex.Game.State
  use GenServer
 
  @fps 30
  @tick_ms div(1000, @fps)
 
  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
  end
 
  @impl true
  def init(_) do
    Process.send_after(self(), :tick, @tick_ms)
    {:ok, %{time: System.monotonic_time(), game_state: State.new()}}
  end
 
  # ...
 
  @impl true
  def handle_info(:tick, state) do
    Process.send_after(self(), :tick, @tick_ms)
    state = tick(state)
    {:noreply, state}
  end
 
 
  defp tick(state) do
    new_time = System.monotonic_time()
    delta_time = new_time - state.time
 
    game_state = State.tick(state.game_state, delta_time)
    Phoenix.PubSub.broadcast(Agarex.PubSub, "game/tick", {"game/tick", game_state})
 
    %{state | time: new_time, game_state: game_state}
  end
end
defmodule Agarex.Game.Server do
  alias Agarex.Game.State
  use GenServer
 
  @fps 30
  @tick_ms div(1000, @fps)
 
  def start_link(_) do
    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
  end
 
  @impl true
  def init(_) do
    Process.send_after(self(), :tick, @tick_ms)
    {:ok, %{time: System.monotonic_time(), game_state: State.new()}}
  end
 
  # ...
 
  @impl true
  def handle_info(:tick, state) do
    Process.send_after(self(), :tick, @tick_ms)
    state = tick(state)
    {:noreply, state}
  end
 
 
  defp tick(state) do
    new_time = System.monotonic_time()
    delta_time = new_time - state.time
 
    game_state = State.tick(state.game_state, delta_time)
    Phoenix.PubSub.broadcast(Agarex.PubSub, "game/tick", {"game/tick", game_state})
 
    %{state | time: new_time, game_state: game_state}
  end
end

defmodule Agarex.Game.Server.State.World do
  defstruct [:players, :agar]
 
  def new() do
    %__MODULE__{
      players: Arrays.new(),
      agar: Arrays.new(),
    }
  end
  
  # ...
end

defmodule Agarex.Game.Server.State.World.Player do
  defstruct [:name, :size, :position, :velocity, :alive?]
 
  def new(name) do
    %__MODULE__{
      name: name,
      size: 1,
      position: {10, 20},
      velocity: {0, 0},
      alive?: true,
    }
  end
  
  # ...
end

defmodule Agarex.Game.LocalState do
  alias __MODULE__.Controls
 
  defstruct [:controls, :game_state, :player_id]
  def new(player_id) do
    %__MODULE__{controls: Controls.new(), game_state: nil, player_id: player_id}
  end
  
  # ...
end

defmodule Agarex.Game.LocalState.Controls do
  defstruct up: false, down: false, left: false, right: false
  def new() do
    %__MODULE__{}
  end
  
  def to_velocity(c) do
    horizontal = bool_to_int(c.right) - bool_to_int(c.left)
    vertical = bool_to_int(c.down) - bool_to_int(c.up)
    {horizontal, vertical}
  end
 
  # ...
end

  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end
  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end
  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end
  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end
  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end
  defmodule AgarexWeb.GameLive do
  # ...
  
  def handle_event(event, params, socket) do
    do_handle_event(event, params, socket)
  end
 
  def handle_info({event, params}, socket) do
    do_handle_event(event, params, socket)
  end
 
  defp do_handle_event(raw_event, params, socket) do
    event = normalize_event(raw_event)
    new_local = Agarex.Game.LocalState.handle_event(event, params, socket.assigns.local)
    socket = assign(socket, :local, new_local)
 
    {:noreply, socket}
  end
 
  defp normalize_event(event) do
    String.split(event, "/")
  end
end

defmodule Agarex.Game.LocalState do
# ...
  def handle_event(event, params, struct) do
    case event do
      ["controls" | rest] ->
        struct = update_in(struct.controls, &Controls.handle_event(rest, params, &1))
        Controls.broadcast_velocity(struct.controls, struct.player_id)
      ["game" , "tick"] ->
        put_in(struct.game_state, params)
    end
  end
end

defmodule Agarex.Game.LocalState.Controls do
  # ...
  def handle_event(event, params, struct) do
    case event do
      ["key_up"] ->
        key_up(struct, params["key"])
      ["key_down"] ->
        key_down(struct, params["key"])
    end
  end
  # ...
end

defmodule Agarex.Effect do
  def effectful_update_in(struct, access_list, function) do
    {result, effects} = 
      struct
      |> Access.get(access_list)
      |> function.()
    struct = put_in(struct, access_list, result)
    {struct, effects}
  end
  
  # arity-2 variant elided
  
end
defmodule Agarex.Effect do
  def effectful_update_in(struct, access_list, function) do
    {result, effects} = 
      struct
      |> Access.get(access_list)
      |> function.()
    struct = put_in(struct, access_list, result)
    {struct, effects}
  end
  
  # arity-2 variant elided
  
end

defmodule Agarex.Effect.BroadcastPlayerMovement do
  defstruct [:player_id, :controls]
  
  def new(player_id, controls) do
    %__MODULE__{player_id: player_id, controls: controls}
  end
end

defmodule Agarex.Game.LocalState do
  # ...
  def handle_event(event, params, struct) do
    case event do
      ["controls" | rest] ->
        struct = update_in(struct.controls, &Controls.handle_event(rest, params, &1))
        Controls.broadcast_velocity(struct.controls, struct.player_id)
      ["game" , "tick"] ->
        put_in(struct.game_state, params)
      end
    end
  end
  # ...
end

defmodule Agarex.Game.LocalState do
  # ...
  def handle_event(event, params, struct) do
    case event do
      ["controls" | rest] ->
        {struct, effects} = 
          Effect.effectful_update_in(struct.controls, &Controls.handle_event(rest, params, &1))
        {
          struct, 
          [Effect.BroadcastPlayerVelocity.new(struct.controls, struct.player_id)] ++ effects
        }
      ["game" , "tick"] ->
        struct = put_in(struct.game_state, params)
        {struct, []}
      end
    end
  end
  # ...
end

module AgarexWeb.EffectInterpreter do
  def run(effect, socket) do
    case effect do
      %Agarex.Effect.BroadcastPlayerVelocity{} ->
        Phoenix.PubSub.broadcast(
          #...
        )
    end
  end
end