From 54dec4c54829a9f03a49f3ead6b62e8d436d71a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Wo=CC=88ginger?= <martin.woeginger@gmail.com>
Date: Wed, 4 Sep 2024 17:48:19 +0200
Subject: [PATCH] parent id can be omitted in case prev id is set

---
 lib/radiator/outline.ex        | 29 ++++++++++++++++++++++++-----
 test/radiator/outline_test.exs | 22 ++++++++++++++++++++--
 test/support/data_case.ex      |  1 +
 3 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/lib/radiator/outline.ex b/lib/radiator/outline.ex
index a0ef53c0..ee478e38 100644
--- a/lib/radiator/outline.ex
+++ b/lib/radiator/outline.ex
@@ -93,12 +93,12 @@ defmodule Radiator.Outline do
         |> where_parent_node_equals(parent_node_id)
         |> Repo.one()
 
-      with parent_node <- NodeRepository.get_node_if(parent_node_id),
-           prev_node <- NodeRepository.get_node_if(prev_node_id),
+      with prev_node <- NodeRepository.get_node_if(prev_node_id),
+           parent_node <- find_parent_node(prev_node, parent_node_id),
            true <- parent_and_prev_consistent?(parent_node, prev_node),
-           {:ok, node} <- NodeRepository.create_node(attrs),
-           {:ok, _node_to_move} <- move_node_if(next_node, parent_node_id, node.uuid),
-           {:ok, node} <- move_node_if(node, parent_node_id, prev_node_id) do
+           true <- episode_valid?(episode_id, parent_node, prev_node),
+           {:ok, node} <- NodeRepository.create_node(set_parent_id_if(attrs, parent_node)),
+           {:ok, _node_to_move} <- move_node_if(next_node, parent_node_id, node.uuid) do
         %NodeRepoResult{node: node, next_id: get_node_id(next_node)}
       else
         false ->
@@ -111,6 +111,25 @@ defmodule Radiator.Outline do
     end)
   end
 
+  defp episode_valid?(episode_id, %Node{episode_id: episode_id}, %Node{episode_id: episode_id}),
+    do: true
+
+  defp episode_valid?(episode_id, %Node{episode_id: episode_id}, nil), do: true
+  defp episode_valid?(episode_id, nil, %Node{episode_id: episode_id}), do: true
+  defp episode_valid?(_episode_id, nil, nil), do: true
+  defp episode_valid?(_episode_id, _parent_node, _prev_node), do: false
+
+  defp set_parent_id_if(attrs, nil), do: attrs
+  defp set_parent_id_if(attrs, %Node{uuid: uuid}), do: Map.put_new(attrs, "parent_id", uuid)
+
+  defp find_parent_node(%Node{parent_id: parent_id}, nil) do
+    NodeRepository.get_node_if(parent_id)
+  end
+
+  defp find_parent_node(_, parent_id) do
+    NodeRepository.get_node_if(parent_id)
+  end
+
   @doc """
   Moves a node to another parent.
 
diff --git a/test/radiator/outline_test.exs b/test/radiator/outline_test.exs
index 3602d132..548bf6b6 100644
--- a/test/radiator/outline_test.exs
+++ b/test/radiator/outline_test.exs
@@ -5,6 +5,7 @@ defmodule Radiator.OutlineTest do
   alias Radiator.Outline
   alias Radiator.Outline.Node
   alias Radiator.Outline.NodeRepository
+  alias Radiator.Podcast
   alias Radiator.PodcastFixtures
 
   import Radiator.OutlineFixtures
@@ -186,6 +187,20 @@ defmodule Radiator.OutlineTest do
       assert new_node.prev_id == nested_node_1.uuid
     end
 
+    test "if prev_id has been given the parent_id can be omitted", %{
+      node_3: node_3,
+      nested_node_1: nested_node_1
+    } do
+      node_attrs = %{
+        "content" => "new node",
+        "episode_id" => node_3.episode_id,
+        "prev_id" => nested_node_1.uuid
+      }
+
+      {:ok, %{node: new_node}} = Outline.insert_node(node_attrs)
+      assert new_node.parent_id == node_3.uuid
+    end
+
     test "all nodes in same level are correctly connected", %{
       node_3: node_3,
       nested_node_1: nested_node_1,
@@ -289,15 +304,18 @@ defmodule Radiator.OutlineTest do
     end
 
     test "in case of error no node gets inserted", %{
+      episode: episode,
       parent_node: parent_node,
       nested_node_1: nested_node_1
     } do
       count_nodes = NodeRepository.count_nodes_by_episode(parent_node.episode_id)
 
+      {:ok, another_episode} =
+        Podcast.create_episode(%{title: "current episode", show_id: episode.show_id, number: 23})
+
       node_attrs = %{
         "content" => "new node",
-        "episode_id" => parent_node.episode_id,
-        "parent_id" => parent_node.uuid,
+        "episode_id" => another_episode.id,
         "prev_id" => nested_node_1.uuid
       }
 
diff --git a/test/support/data_case.ex b/test/support/data_case.ex
index a7e9ee3d..a24c1d57 100644
--- a/test/support/data_case.ex
+++ b/test/support/data_case.ex
@@ -177,6 +177,7 @@ defmodule Radiator.DataCase do
     assert nested_node_2.prev_id == nested_node_1.uuid
 
     %{
+      episode: episode,
       node_1: node_1,
       node_2: node_2,
       node_3: node_3,