⚡ Remove some unnecessary database queries

RustySnek · Oct 8, 2023 · 965c27e · 965c27e
1 parent 309414c
commit 965c27e
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Showing 2 changed files with 34 additions and 44 deletions.
diff --git a/lib/drag_board/board_tasks.ex b/lib/drag_board/board_tasks.ex
@@ -9,21 +9,6 @@ defmodule DragBoard.BoardTasks do
     |> Repo.one()
   end
 
-  defp move_tasks(tasks_to_move) do
-    fn repo, _ ->
-      try do
-        Enum.each(tasks_to_move, fn changeset ->
-          repo.update(changeset)
-        end)
-
-        {:ok, "Tasks moved successfully"}
-      catch
-        :error, reason ->
-          {:error, reason}
-      end
-    end
-  end
-
   defp get_last_task_position(board) do
     # Returns a -1 if the there are no other tasks, so when new one is created its position will be 0.
     case length(board.board_tasks) do
@@ -37,14 +22,23 @@ defmodule DragBoard.BoardTasks do
     end
   end
 
+  def remove_task(task_id) do
+    task = get_task_by_id(task_id)
+
+    Ecto.Multi.new()
+    |> Ecto.Multi.delete(:remove_task, task)
+    |> Repo.transaction()
+  end
+
   def add_task(name, board_id) do
     board = Boards.get_board_with_desc_tasks_by_id(board_id)
 
     last_position = get_last_task_position(board)
+    new_task = TaskQueries.new_board_task(board, name, last_position)
 
-    board
-    |> TaskQueries.new_board_task(name, last_position)
-    |> Repo.insert!()
+    Ecto.Multi.new()
+    |> Ecto.Multi.insert(:insert_new_task, new_task)
+    |> Repo.transaction()
   end
 
   def move_leftover_tasks_from_above_down(old_position, new_position, task_id, board_id) do
@@ -71,22 +65,10 @@ defmodule DragBoard.BoardTasks do
     end
   end
 
-  def move_task_board(previous_board_id, board_id, task_id, new_position, old_position) do
-    _move_task =
+  def move_task_board(board_id, task_id, new_position) do
+    move_task =
       get_task_by_id(task_id)
       |> BoardTask.changeset(%{"position" => new_position, "board_id" => board_id})
-      |> Repo.update!()
-
-    tasks_to_move =
-      TaskQueries.all_by_board_id(previous_board_id)
-      |> TaskQueries.get_leftover_tasks_from_below_without_new_position(old_position, task_id)
-      |> Repo.all()
-
-    moved_tasks_in_previous_board =
-      for task <- tasks_to_move do
-        new_position = task.position - 1
-        BoardTask.changeset(task, %{"position" => new_position})
-      end
 
     tasks_to_move =
       TaskQueries.all_by_board_id(board_id)
@@ -99,20 +81,20 @@ defmodule DragBoard.BoardTasks do
         BoardTask.changeset(task, %{"position" => new_position})
       end
 
-    move_tasks_in_current_board = move_tasks(moved_tasks_in_current_board)
-    move_tasks_in_previous_board = move_tasks(moved_tasks_in_previous_board)
+    multi = Ecto.Multi.new()
 
-    Ecto.Multi.new()
-    |> Ecto.Multi.run(:move_tasks_in_previous_board, move_tasks_in_previous_board)
-    |> Ecto.Multi.run(:move_tasks_in_current_board, move_tasks_in_current_board)
+    Enum.reduce(moved_tasks_in_current_board, multi, fn change, multi ->
+      id = Ecto.Changeset.get_field(change, :id)
+      Ecto.Multi.update(multi, {:move_task, id}, change)
+    end)
+    |> Ecto.Multi.update(:move_task, move_task)
     |> Repo.transaction()
   end
 
   def move_task_position(old_position, new_position, task_id, board_id) do
-    _move_task =
+    move_task =
       get_task_by_id(task_id)
       |> BoardTask.changeset(%{"position" => new_position})
-      |> Repo.update!()
 
     moved_tasks =
       cond do
@@ -126,10 +108,14 @@ defmodule DragBoard.BoardTasks do
           []
       end
 
-    move_tasks = move_tasks(moved_tasks)
+    multi = Ecto.Multi.new()
 
-    Ecto.Multi.new()
-    |> Ecto.Multi.run(:move_tasks, move_tasks)
+    moved_tasks
+    |> Enum.reduce(multi, fn change, multi ->
+      id = Ecto.Changeset.get_field(change, :id)
+      Ecto.Multi.update(multi, {:move_task, id}, change)
+    end)
+    |> Ecto.Multi.update(:move_task, move_task)
     |> Repo.transaction()
   end
 end
diff --git a/lib/drag_board/boards.ex b/lib/drag_board/boards.ex
@@ -6,7 +6,7 @@ defmodule DragBoard.Boards do
 
   def get_board_by_id(board_id) do
     BoardQueries.with_id(board_id)
-    |> Repo.all()
+    |> Repo.one()
   end
 
   def get_board_with_desc_tasks_by_id(board_id) do
@@ -20,14 +20,18 @@ defmodule DragBoard.Boards do
     |> Repo.all()
   end
 
+  def remove_board(board_id) do
+    BoardQueries.with_id(board_id)
+    |> Repo.delete_all()
+  end
+
   def add_board(name, group) do
     changeset =
       %Board{}
       |> Board.changeset(%{name: name, group: group})
 
     Ecto.Multi.new()
     |> Ecto.Multi.insert(:insert_board, changeset)
-    |> Ecto.Multi.all(:list_boards, BoardQueries.list_boards_with_tasks())
     |> Repo.transaction()
   end
 end