Implement pause and resume

lib/sergei/consumer.ex

@@ -1,6 +1,7 @@
 defmodule Sergei.Consumer do
   use Nostrum.Consumer
 
+  require Logger
   alias Nostrum.Api
 
   # Translate params to list of maps
@@ -15,6 +16,8 @@ defmodule Sergei.Consumer do
 
   @slash_commands [
     {"ping", "Pong", []},
+    {"pause", "Pause media playback", []},
+    {"resume", "Resume media playback", []},
     {"play", "Play some tunes", @play_opts}
   ]
 
@@ -99,4 +102,28 @@ defmodule Sergei.Consumer do
         {:error, "You are not in a voice channel."}
     end
   end
+
+  # /pause
+  def do_command(%{guild_id: guild_id, data: %{name: "pause"}}) do
+    case Sergei.Player.pause(guild_id) do
+      :ok ->
+        {:ok, "Pausing..."}
+
+      {:error, err} ->
+        Logger.error("Failed to pause media: #{err}")
+        {:error, "This is embarrasing..."}
+    end
+  end
+
+  # /resume
+  def do_command(%{guild_id: guild_id, data: %{name: "resume"}}) do
+    case Sergei.Player.resume(guild_id) do
+      :ok ->
+        {:ok, "Resuming..."}
+
+      {:error, err} ->
+        Logger.error("Failed to resume media: #{err}")
+        {:error, "This is embarrasing..."}
+    end
+  end
 end

lib/sergei/player.ex

@@ -20,6 +20,14 @@ defmodule Sergei.Player do
     GenServer.call(__MODULE__, {:play, guild_id, channel_id, url})
   end
 
+  def pause(guild_id) do
+    GenServer.call(__MODULE__, {:pause, guild_id})
+  end
+
+  def resume(guild_id) do
+    GenServer.call(__MODULE__, {:resume, guild_id})
+  end
+
   # Server
   @impl true
   def handle_info(:tick, state) do
@@ -47,6 +55,39 @@ defmodule Sergei.Player do
     {:reply, res, state}
   end
 
+  @impl true
+  def handle_call({_, guild_id}, _from, state) when not is_map_key(state, guild_id) do
+    {:reply, {:error, "I'm not playing anything right now"}, state}
+  end
+
+  @impl true
+  def handle_call({:pause, guild_id}, _from, state) do
+    %{url: url} = Map.fetch!(state, guild_id)
+    Voice.pause(guild_id)
+
+    state =
+      Map.put(state, guild_id, %{
+        url: url,
+        paused: true
+      })
+
+    {:reply, :ok, state}
+  end
+
+  @impl true
+  def handle_call({:resume, guild_id}, _from, state) do
+    %{url: url} = Map.fetch!(state, guild_id)
+    Voice.resume(guild_id)
+
+    state =
+      Map.put(state, guild_id, %{
+        url: url,
+        paused: false
+      })
+
+    {:reply, :ok, state}
+  end
+
   def play_music(guild_id, channel_id, url) do
     cond do
       Voice.get_channel_id(guild_id) != channel_id ->