Channel automatic update move

lib/philomena/channels.ex

@@ -6,49 +6,15 @@ defmodule Philomena.Channels do
   import Ecto.Query, warn: false
   alias Philomena.Repo
 
+  alias Philomena.Channels.AutomaticUpdater
   alias Philomena.Channels.Channel
-  alias Philomena.Channels.PicartoChannel
-  alias Philomena.Channels.PiczelChannel
   alias Philomena.Notifications
 
   @doc """
-  Updates all the tracked channels for which an update
-  scheme is known.
+  Updates all the tracked channels for which an update scheme is known.
   """
   def update_tracked_channels! do
-    now = DateTime.utc_now() |> DateTime.truncate(:second)
-
-    picarto_channels = PicartoChannel.live_channels(now)
-    live_picarto_channels = Map.keys(picarto_channels)
-
-    piczel_channels = PiczelChannel.live_channels(now)
-    live_piczel_channels = Map.keys(piczel_channels)
-
-    # Update all channels which are offline to reflect offline status
-    offline_query =
-      from c in Channel,
-        where: c.type == "PicartoChannel" and c.short_name not in ^live_picarto_channels,
-        or_where: c.type == "PiczelChannel" and c.short_name not in ^live_piczel_channels
-
-    Repo.update_all(offline_query, set: [is_live: false, updated_at: now])
-
-    # Update all channels which are online to reflect online status using
-    # changeset functions
-    online_query =
-      from c in Channel,
-        where: c.type == "PicartoChannel" and c.short_name in ^live_picarto_channels,
-        or_where: c.type == "PiczelChannel" and c.short_name in ^live_picarto_channels
-
-    online_query
-    |> Repo.all()
-    |> Enum.map(fn
-      %{type: "PicartoChannel", short_name: name} = channel ->
-        Channel.update_changeset(channel, Map.get(picarto_channels, name, []))
-
-      %{type: "PiczelChannel", short_name: name} = channel ->
-        Channel.update_changeset(channel, Map.get(piczel_channels, name, []))
-    end)
-    |> Enum.map(&Repo.update!/1)
+    AutomaticUpdater.update_tracked_channels!()
   end
 
   @doc """
@@ -103,6 +69,24 @@ defmodule Philomena.Channels do
     |> Repo.update()
   end
 
+  @doc """
+  Updates a channel's state when it goes live.
+
+  ## Examples
+
+      iex> update_channel_state(channel, %{field: new_value})
+      {:ok, %Channel{}}
+
+      iex> update_channel_state(channel, %{field: bad_value})
+      {:error, %Ecto.Changeset{}}
+
+  """
+  def update_channel_state(%Channel{} = channel, attrs) do
+    channel
+    |> Channel.update_changeset(attrs)
+    |> Repo.update()
+  end
+
   @doc """
   Deletes a Channel.
 

lib/philomena/channels/automatic_updater.ex

@@ -0,0 +1,64 @@
+defmodule Philomena.Channels.AutomaticUpdater do
+  @moduledoc """
+  Automatic update routine for streams.
+
+  Calls APIs for each stream provider to remove channels which are no longer online,
+  and to restore channels which are currently online.
+  """
+
+  import Ecto.Query, warn: false
+  alias Philomena.Repo
+
+  alias Philomena.Channels
+  alias Philomena.Channels.Channel
+  alias Philomena.Channels.PicartoChannel
+  alias Philomena.Channels.PiczelChannel
+
+  @doc """
+  Updates all the tracked channels for which an update scheme is known.
+  """
+  def update_tracked_channels! do
+    now = DateTime.utc_now(:second)
+    Enum.each(providers(), &update_provider(&1, now))
+  end
+
+  defp providers do
+    [
+      {"PicartoChannel", PicartoChannel.live_channels()},
+      {"PiczelChannel", PiczelChannel.live_channels()}
+    ]
+  end
+
+  defp update_provider({provider_name, live_channels}, now) do
+    channel_names = Map.keys(live_channels)
+
+    provider_name
+    |> update_offline_query(channel_names, now)
+    |> Repo.update_all([])
+
+    provider_name
+    |> online_query(channel_names)
+    |> Repo.all()
+    |> Enum.each(&update_online_channel(&1, live_channels, now))
+  end
+
+  defp update_offline_query(provider_name, channel_names, now) do
+    from c in Channel,
+      where: c.type == ^provider_name and c.short_name not in ^channel_names,
+      update: [set: [is_live: false, updated_at: ^now]]
+  end
+
+  defp online_query(provider_name, channel_names) do
+    from c in Channel,
+      where: c.type == ^provider_name and c.short_name in ^channel_names
+  end
+
+  defp update_online_channel(channel, live_channels, now) do
+    attrs =
+      live_channels
+      |> Map.get(channel.short_name, %{})
+      |> Map.merge(%{last_live_at: now, last_fetched_at: now})
+
+    Channels.update_channel_state(channel, attrs)
+  end
+end

lib/philomena/channels/picarto_channel.ex

@@ -1,30 +1,28 @@
 defmodule Philomena.Channels.PicartoChannel do
   @api_online "https://api.picarto.tv/api/v1/online?adult=true&gaming=true"
 
-  @spec live_channels(DateTime.t()) :: map()
-  def live_channels(now) do
+  @spec live_channels() :: map()
+  def live_channels do
     @api_online
     |> PhilomenaProxy.Http.get()
     |> case do
       {:ok, %{body: body, status: 200}} ->
         body
         |> Jason.decode!()
-        |> Map.new(&{&1["name"], fetch(&1, now)})
+        |> Map.new(&{&1["name"], fetch(&1)})
 
       _error ->
         %{}
     end
   end
 
-  defp fetch(api, now) do
+  defp fetch(api) do
     %{
       title: api["title"],
       is_live: true,
       nsfw: api["adult"],
       viewers: api["viewers"],
       thumbnail_url: api["thumbnails"]["web"],
-      last_fetched_at: now,
-      last_live_at: now,
       description: nil
     }
   end

lib/philomena/channels/piczel_channel.ex

@@ -1,30 +1,28 @@
 defmodule Philomena.Channels.PiczelChannel do
   @api_online "https://api.piczel.tv/api/streams"
 
-  @spec live_channels(DateTime.t()) :: map()
-  def live_channels(now) do
+  @spec live_channels() :: map()
+  def live_channels do
     @api_online
     |> PhilomenaProxy.Http.get()
     |> case do
       {:ok, %{body: body, status: 200}} ->
         body
         |> Jason.decode!()
-        |> Map.new(&{&1["slug"], fetch(&1, now)})
+        |> Map.new(&{&1["slug"], fetch(&1)})
 
       _error ->
         %{}
     end
   end
 
-  defp fetch(api, now) do
+  defp fetch(api) do
     %{
       title: api["title"],
       is_live: api["live"],
       nsfw: api["adult"],
       viewers: api["viewers"],
-      thumbnail_url: api["user"]["avatar"]["avatar"]["url"],
-      last_fetched_at: now,
-      last_live_at: now
+      thumbnail_url: api["user"]["avatar"]["avatar"]["url"]
     }
   end
 end