Merge pull request #5 from chrismccord/feature/validate_max_songs_per_account

Limit # of songs per account

lib/live_beats/accounts/user.ex

@@ -4,6 +4,7 @@ defmodule LiveBeats.Accounts.User do
 
   alias LiveBeats.Accounts.{User, Identity}
 
+
   schema "users" do
     field :email, :string
     field :name, :string
@@ -14,6 +15,7 @@ defmodule LiveBeats.Accounts.User do
     field :active_profile_user_id, :id
     field :avatar_url, :string
     field :external_homepage_url, :string
+    field :songs_number, :integer
 
     has_many :identities, Identity
 
@@ -59,6 +61,7 @@ defmodule LiveBeats.Accounts.User do
     |> validate_username()
   end
 
+
   defp validate_email(changeset) do
     changeset
     |> validate_required([:email])

lib/live_beats/media_library.ex

@@ -11,6 +11,7 @@ defmodule LiveBeats.MediaLibrary do
 
   @pubsub LiveBeats.PubSub
   @auto_next_threshold_seconds 5
+  @max_songs 30
 
   defdelegate stopped?(song), to: Song
   defdelegate playing?(song), to: Song
@@ -157,6 +158,27 @@ defmodule LiveBeats.MediaLibrary do
 
         Ecto.Multi.insert(acc, {:song, ref}, chset)
       end)
+      |> Ecto.Multi.run(:valid_songs_number, fn _repo, changes ->
+        user = Accounts.get_user!(user.id)
+        new_songs_count = changes |> Enum.filter(&match?({{:song, _ref}, _}, &1)) |> Enum.count()
+        validate_songs_limit(user.songs_number, new_songs_count)
+      end)
+      |> Ecto.Multi.update_all(
+        :update_songs_number,
+        fn %{valid_songs_number: new_songs_count} ->
+          from(u in Accounts.User,
+            where: u.id == ^user.id and u.songs_number == ^user.songs_number,
+            update: [inc: [songs_number: ^new_songs_count]]
+          )
+        end,
+        []
+      )
+      |> Ecto.Multi.run(:is_songs_number_updated?, fn _repo, %{update_songs_number: result} ->
+        case result do
+          {1, _} -> {:ok, user}
+          _ -> {:error, :invalid}
+        end
+      end)
 
     case LiveBeats.Repo.transaction(multi) do
       {:ok, results} ->
@@ -169,8 +191,15 @@ defmodule LiveBeats.MediaLibrary do
          end)
          |> Enum.into(%{})}
 
-      {:error, _failed_op, _failed_val, _changes} ->
+      {:error, failed_op, failed_val, _changes} ->
-        {:error, :invalid}
+        failed_op =
+          case failed_op do
+            {:song, _number} -> :invalid_song
+            :is_songs_number_updated? -> :invalid
+            failed_op -> failed_op
+          end
+
+        {:error, {failed_op, failed_val}}
     end
   end
 
@@ -314,7 +343,20 @@ defmodule LiveBeats.MediaLibrary do
         )
     end
 
-    Repo.delete(song)
+    Ecto.Multi.new()
+    |> Ecto.Multi.delete(:delete, song)
+    |> Ecto.Multi.update_all(
+        :update_songs_number,
+        fn _ ->
+          from(u in Accounts.User,
+            where: u.id == ^song.user_id,
+            update: [inc: [songs_number: -1]]
+          )
+        end,
+        []
+      )
+    |> Repo.transaction()
+
   end
 
   def change_song(song_or_changeset, attrs \\ %{})
@@ -338,4 +380,12 @@ defmodule LiveBeats.MediaLibrary do
   end
 
   defp topic(user_id) when is_integer(user_id), do: "profile:#{user_id}"
+
+  defp validate_songs_limit(user_songs, new_songs_count) do
+    if user_songs + new_songs_count <= @max_songs do
+      {:ok, new_songs_count}
+    else
+      {:error, :songs_limit_exceeded}
+    end
+  end
 end

lib/live_beats_web/live/song_live/upload_form_component.ex

@@ -56,8 +56,12 @@ defmodule LiveBeatsWeb.SongLive.UploadFormComponent do
            |> put_flash(:info, "#{map_size(songs)} song(s) uploaded")
            |> push_redirect(to: profile_path(current_user))}
 
-        {:error, _reason} ->
+        {:error, error} ->
-          {:noreply, socket}
+          updated_socket =
+            socket
+            |> update(:error_messages, &Enum.take(&1 ++ [error], -10))
+
+          {:noreply, updated_socket}
       end
     end
   end
@@ -148,6 +152,15 @@ defmodule LiveBeatsWeb.SongLive.UploadFormComponent do
   defp file_error(%{kind: :not_accepted} = assigns), do: ~H|not a valid MP3 file|
   defp file_error(%{kind: :too_many_files} = assigns), do: ~H|too many files|
 
+  defp file_error(%{kind: :songs_limit_exceeded} = assigns),
+    do: ~H|You exceeded the limit of songs per account|
+
+  defp file_error(%{kind: :invalid} = assigns), do: ~H|Something went wrong|
+
+  defp file_error(%{kind: %Ecto.Changeset{} = changeset} = assigns)  do
+    ~H|<%=  LiveBeatsWeb.ErrorHelpers.translate_changeset_errors(@kind) %>|
+  end
+
   defp file_error(%{kind: {msg, opts}} = assigns) when is_binary(msg) and is_list(opts) do
     ~H|<%= LiveBeatsWeb.ErrorHelpers.translate_error(@kind) %>|
   end
@@ -190,7 +203,7 @@ defmodule LiveBeatsWeb.SongLive.UploadFormComponent do
     socket
     |> cancel_upload(:mp3, entry.ref)
     |> drop_changeset(entry.ref)
-    |> update(:error_messages, &(Enum.take(&1 ++ [{entry.client_name, reason}], -10)))
+    |> update(:error_messages, &Enum.take(&1 ++ [{entry.client_name, reason}], -10))
   end
 
   defp get_entry!(socket, entry_ref) do

lib/live_beats_web/views/error_helpers.ex

@@ -63,4 +63,10 @@ defmodule LiveBeatsWeb.ErrorHelpers do
       Gettext.dgettext(LiveBeatsWeb.Gettext, "errors", msg, opts)
     end
   end
+
+  def translate_changeset_errors(changeset) do
+    changeset.errors
+    |> Enum.map(fn {key, value} -> "#{key} #{translate_error(value)}" end)
+    |> Enum.join("\n")
+  end
 end

priv/repo/migrations/20211117174157_add_songs_number_to_users.exs

@@ -0,0 +1,20 @@
+defmodule LiveBeats.Repo.Migrations.AddSongsNumberToUsers do
+  use Ecto.Migration
+
+  def up do
+    alter table(:users) do
+      add :songs_number, :integer, null: false, default: 0
+    end
+
+    execute("
+      UPDATE users set songs_number =
+        (SELECT count (*) from songs
+          where songs.user_id = users.id)")
+  end
+
+  def down do
+    alter table(:users) do
+      remove :songs_number
+    end
+  end
+end