From ea273fe149ce87aa5ad0df47aa78fb6dc0128742 Mon Sep 17 00:00:00 2001
From: DecafMango <DecafMangoITMO@yandex.ru>
Date: Mon, 9 Dec 2024 17:40:51 +0300
Subject: [PATCH 1/2] add rest just for files

---
 lib/backend/files/file.ex                     | 20 +++++++
 lib/backend/files/files.ex                    | 28 ++++++++++
 lib/backend/schemas/file.ex                   | 12 ----
 lib/backend/schemas/user.ex                   | 12 ----
 .../controllers/file_controller.ex            | 56 +++++++++++++++++++
 lib/backend_web/router.ex                     |  6 +-
 mix.lock                                      |  2 +-
 .../migrations/20241129212331_add_user.exs    | 10 ----
 .../migrations/20241129212656_add_file.exs    |  4 +-
 9 files changed, 112 insertions(+), 38 deletions(-)
 create mode 100644 lib/backend/files/file.ex
 create mode 100644 lib/backend/files/files.ex
 delete mode 100644 lib/backend/schemas/file.ex
 delete mode 100644 lib/backend/schemas/user.ex
 create mode 100644 lib/backend_web/controllers/file_controller.ex
 delete mode 100644 priv/repo/migrations/20241129212331_add_user.exs

diff --git a/lib/backend/files/file.ex b/lib/backend/files/file.ex
new file mode 100644
index 0000000..2c37e75
--- /dev/null
+++ b/lib/backend/files/file.ex
@@ -0,0 +1,20 @@
+defmodule Backend.Files.File do
+  @moduledoc """
+  PostgreSQL schema: `File`
+  > Managed by *Ecto ORM*
+  """
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  @derive {Jason.Encoder, only: [:id, :name, :content]}
+  schema "files" do
+    field :name, :string
+    field :content, :string
+  end
+
+  def changeset(file, attrs) do
+    file
+    |> cast(attrs, [:name, :content], empty_values: [:content])
+    |> validate_required([:name])
+  end
+end
diff --git a/lib/backend/files/files.ex b/lib/backend/files/files.ex
new file mode 100644
index 0000000..4ad5649
--- /dev/null
+++ b/lib/backend/files/files.ex
@@ -0,0 +1,28 @@
+defmodule Backend.Files do
+  @moduledoc """
+  Context for File
+  """
+  alias Backend.Repo
+  alias Backend.Files.File
+
+  def get_file(id) do
+    Repo.get(File, id)
+  end
+
+  def create_file(attrs \\ %{}) do
+    %File{}
+    |> File.changeset(attrs)
+    |> Repo.insert()
+  end
+
+  def save_file(file) do
+    file
+    |> File.changeset(%{})
+    |> Repo.update()
+  end
+
+  def delete_file(file) do
+    file
+    |> Repo.delete()
+  end
+end
diff --git a/lib/backend/schemas/file.ex b/lib/backend/schemas/file.ex
deleted file mode 100644
index b89c1d9..0000000
--- a/lib/backend/schemas/file.ex
+++ /dev/null
@@ -1,12 +0,0 @@
-defmodule Backend.File do
-  @moduledoc """
-  PostgreSQL schema: `File`
-  > Managed by *Ecto ORM*
-  """
-  use Ecto.Schema
-
-  schema "files" do
-    field :filename, :string
-    field :created_at, :date
-  end
-end
diff --git a/lib/backend/schemas/user.ex b/lib/backend/schemas/user.ex
deleted file mode 100644
index 162a871..0000000
--- a/lib/backend/schemas/user.ex
+++ /dev/null
@@ -1,12 +0,0 @@
-defmodule Backend.User do
-  @moduledoc """
-  PostgreSQL schema: `User`
-  > Managed by *Ecto ORM*
-  """
-  use Ecto.Schema
-
-  schema "users" do
-    field :username, :string
-    field :password, :string
-  end
-end
diff --git a/lib/backend_web/controllers/file_controller.ex b/lib/backend_web/controllers/file_controller.ex
new file mode 100644
index 0000000..4d97003
--- /dev/null
+++ b/lib/backend_web/controllers/file_controller.ex
@@ -0,0 +1,56 @@
+defmodule BackendWeb.FileController do
+  alias Backend.Files
+  use BackendWeb, :controller
+
+  def get_file(conn, %{"id" => id}) do
+    file = Files.get_file(id)
+
+    case file do
+      nil ->
+        conn
+        |> put_status(404)
+        |> json(%{"message" => "File with id " <> id <> " does not exist"})
+
+      _ ->
+        conn
+        |> put_status(200)
+        |> json(file)
+    end
+  end
+
+  def create_file(conn, %{"name" => name}) do
+    case Files.create_file(%{"name" => name, "content" => ""}) do
+      {:ok, file} ->
+        conn
+        |> put_status(201)
+        |> json(file)
+
+      {:error, _} ->
+        conn
+        |> put_status(500)
+        |> json(%{"message" => "Error occured"})
+    end
+  end
+
+  def delete_file(conn, %{"id" => id}) do
+    file = Files.get_file(id)
+
+    if file == nil do
+      conn
+      |> put_status(404)
+      |> json(%{"message" => "File with id " <> id <> " not found"})
+    else
+      case Files.delete_file(file) do
+        {:ok, _} ->
+          conn
+          |> put_status(200)
+          |> json(%{"message" => "File with id " <> id <> " has been deleted successfully"})
+
+        {:error, _} ->
+          conn
+          |> put_status(500)
+          |> json(%{"message" => "Error occured"})
+      end
+    end
+  end
+end
diff --git a/lib/backend_web/router.ex b/lib/backend_web/router.ex
index bab5e1d..70eb75f 100644
--- a/lib/backend_web/router.ex
+++ b/lib/backend_web/router.ex
@@ -6,7 +6,7 @@ defmodule BackendWeb.Router do
     plug :fetch_session
     plug :fetch_live_flash
     plug :put_root_layout, html: {BackendWeb.Layouts, :root}
-    plug :protect_from_forgery
+    # plug :protect_from_forgery
     plug :put_secure_browser_headers
   end
 
@@ -18,6 +18,10 @@ defmodule BackendWeb.Router do
     pipe_through :browser
 
     get "/", PageController, :home
+
+    get "/file/:id", FileController, :get_file
+    post "/file", FileController, :create_file
+    delete "/file/:id", FileController, :delete_file
   end
 
   # Other scopes may use custom stacks.
diff --git a/mix.lock b/mix.lock
index 381c9de..ea856cf 100644
--- a/mix.lock
+++ b/mix.lock
@@ -19,7 +19,7 @@
   "finch": {:hex, :finch, "0.19.0", "c644641491ea854fc5c1bbaef36bfc764e3f08e7185e1f084e35e0672241b76d", [:mix], [{:mime, "~> 1.0 or ~> 2.0", [hex: :mime, repo: "hexpm", optional: false]}, {:mint, "~> 1.6.2 or ~> 1.7", [hex: :mint, repo: "hexpm", optional: false]}, {:nimble_options, "~> 0.4 or ~> 1.0", [hex: :nimble_options, repo: "hexpm", optional: false]}, {:nimble_pool, "~> 1.1", [hex: :nimble_pool, repo: "hexpm", optional: false]}, {:telemetry, "~> 0.4 or ~> 1.0", [hex: :telemetry, repo: "hexpm", optional: false]}], "hexpm", "fc5324ce209125d1e2fa0fcd2634601c52a787aff1cd33ee833664a5af4ea2b6"},
   "floki": {:hex, :floki, "0.36.3", "1102f93b16a55bc5383b85ae3ec470f82dee056eaeff9195e8afdf0ef2a43c30", [:mix], [], "hexpm", "fe0158bff509e407735f6d40b3ee0d7deb47f3f3ee7c6c182ad28599f9f6b27a"},
   "gettext": {:hex, :gettext, "0.26.2", "5978aa7b21fada6deabf1f6341ddba50bc69c999e812211903b169799208f2a8", [:mix], [{:expo, "~> 0.5.1 or ~> 1.0", [hex: :expo, repo: "hexpm", optional: false]}], "hexpm", "aa978504bcf76511efdc22d580ba08e2279caab1066b76bb9aa81c4a1e0a32a5"},
-  "heroicons": {:git, "https://github.com/tailwindlabs/heroicons.git", "88ab3a0d790e6a47404cba02800a6b25d2afae50", [tag: "v2.1.1", sparse: "optimized"]},
+  "heroicons": {:git, "https://github.com/tailwindlabs/heroicons.git", "88ab3a0d790e6a47404cba02800a6b25d2afae50", [tag: "v2.1.1", sparse: "optimized", depth: 1]},
   "hpax": {:hex, :hpax, "1.0.0", "28dcf54509fe2152a3d040e4e3df5b265dcb6cb532029ecbacf4ce52caea3fd2", [:mix], [], "hexpm", "7f1314731d711e2ca5fdc7fd361296593fc2542570b3105595bb0bc6d0fad601"},
   "jason": {:hex, :jason, "1.4.4", "b9226785a9aa77b6857ca22832cffa5d5011a667207eb2a0ad56adb5db443b8a", [:mix], [{:decimal, "~> 1.0 or ~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "c5eb0cab91f094599f94d55bc63409236a8ec69a21a67814529e8d5f6cc90b3b"},
   "libgraph": {:hex, :libgraph, "0.16.0", "3936f3eca6ef826e08880230f806bfea13193e49bf153f93edcf0239d4fd1d07", [:mix], [], "hexpm", "41ca92240e8a4138c30a7e06466acc709b0cbb795c643e9e17174a178982d6bf"},
diff --git a/priv/repo/migrations/20241129212331_add_user.exs b/priv/repo/migrations/20241129212331_add_user.exs
deleted file mode 100644
index cc07447..0000000
--- a/priv/repo/migrations/20241129212331_add_user.exs
+++ /dev/null
@@ -1,10 +0,0 @@
-defmodule Backend.Repo.Migrations.AddUser do
-  use Ecto.Migration
-
-  def change do
-    create table(:users) do
-      add :username, :string
-      add :password, :string
-    end
-  end
-end
diff --git a/priv/repo/migrations/20241129212656_add_file.exs b/priv/repo/migrations/20241129212656_add_file.exs
index 7e35229..0f9d2e0 100644
--- a/priv/repo/migrations/20241129212656_add_file.exs
+++ b/priv/repo/migrations/20241129212656_add_file.exs
@@ -3,8 +3,8 @@ defmodule Backend.Repo.Migrations.AddFile do
 
   def change do
     create table(:files) do
-      add :filename, :string
-      add :created_at, :date
+      add :name, :string, null: false
+      add :content, :binary
     end
   end
 end

From 563f7ee095ff32d532825740e9189fd6274cbfb1 Mon Sep 17 00:00:00 2001
From: DecafMango <DecafMangoITMO@yandex.ru>
Date: Wed, 11 Dec 2024 00:25:07 +0300
Subject: [PATCH 2/2] add file manager

---
 lib/backend/application.ex                    |  4 +-
 lib/backend/files/file.ex                     |  6 +-
 lib/backend/files/file_manager.ex             | 57 +++++++++++++++++++
 lib/backend/files/file_process.ex             | 49 ++++++++++++++++
 lib/backend/files/file_registry.ex            | 23 ++++++++
 lib/backend/files/files.ex                    |  8 ++-
 lib/backend_web/channels/room_channel.ex      | 17 +++++-
 .../migrations/20241129212656_add_file.exs    |  2 +-
 8 files changed, 155 insertions(+), 11 deletions(-)
 create mode 100644 lib/backend/files/file_manager.ex
 create mode 100644 lib/backend/files/file_process.ex
 create mode 100644 lib/backend/files/file_registry.ex

diff --git a/lib/backend/application.ex b/lib/backend/application.ex
index 230fc68..5ef4648 100644
--- a/lib/backend/application.ex
+++ b/lib/backend/application.ex
@@ -17,7 +17,9 @@ defmodule Backend.Application do
       # Start a worker by calling: Backend.Worker.start_link(arg)
       # {Backend.Worker, arg},
       # Start to serve requests, typically the last entry
-      BackendWeb.Endpoint
+      BackendWeb.Endpoint,
+      Backend.Files.FileRegistry,
+      Backend.Files.FileManager
     ]
 
     # See https://hexdocs.pm/elixir/Supervisor.html
diff --git a/lib/backend/files/file.ex b/lib/backend/files/file.ex
index 2c37e75..f273bf7 100644
--- a/lib/backend/files/file.ex
+++ b/lib/backend/files/file.ex
@@ -12,9 +12,7 @@ defmodule Backend.Files.File do
     field :content, :string
   end
 
-  def changeset(file, attrs) do
-    file
-    |> cast(attrs, [:name, :content], empty_values: [:content])
-    |> validate_required([:name])
+  def changeset(file, attr) do
+    cast(file, attr, [:name, :content])
   end
 end
diff --git a/lib/backend/files/file_manager.ex b/lib/backend/files/file_manager.ex
new file mode 100644
index 0000000..0abd7d9
--- /dev/null
+++ b/lib/backend/files/file_manager.ex
@@ -0,0 +1,57 @@
+defmodule Backend.Files.FileManager do
+  @moduledoc """
+  FileManager used for creating and interacting with FileProcess
+  """
+
+  alias Backend.Files.FileProcess
+
+  def start_link() do
+    IO.puts("Starting file manager")
+
+    DynamicSupervisor.start_link(
+      name: __MODULE__,
+      strategy: :one_for_one
+    )
+  end
+
+  defp start_child(file_id) do
+    DynamicSupervisor.start_child(
+      __MODULE__,
+      {Backend.Files.FileProcess, file_id}
+    )
+  end
+
+  @spec child_spec(any()) :: %{
+          id: Backend.Files.FileManager,
+          start: {Backend.Files.FileManager, :start_link, []},
+          type: :supervisor
+        }
+  def child_spec(_arg) do
+    %{
+      id: __MODULE__,
+      start: {__MODULE__, :start_link, []},
+      type: :supervisor
+    }
+  end
+
+  def get_or_start_process(file_id) do
+    case Registry.lookup(Backend.Files.FileRegistry, file_id) do
+      [] ->
+        # Процесс не существует — запускаем новый
+        start_child(file_id)
+        :ok
+
+      [{_pid, _}] ->
+        # Процесс уже существует
+        :ok
+    end
+  end
+
+  def update_file_content(file_id, content) do
+    # Убедимся, что процесс существует
+    get_or_start_process(file_id)
+
+    # Обновляем содержимое файла в процессе
+    FileProcess.update_content(file_id, content)
+  end
+end
diff --git a/lib/backend/files/file_process.ex b/lib/backend/files/file_process.ex
new file mode 100644
index 0000000..3d7b210
--- /dev/null
+++ b/lib/backend/files/file_process.ex
@@ -0,0 +1,49 @@
+defmodule Backend.Files.FileProcess do
+  @moduledoc """
+  FileProcess used to cashing file's text (just for reduce interaction with DB)
+  """
+
+  use GenServer, restart: :temporary
+  alias Backend.Files
+
+  # Время бездействия (например, 5 секунд)
+  @timeout 5_000
+
+  # API
+  def start_link(file_id) do
+    GenServer.start_link(__MODULE__, file_id, name: via_tuple(file_id))
+  end
+
+  def update_content(file_id, new_content) do
+    GenServer.call(via_tuple(file_id), {:update_content, new_content})
+  end
+
+  defp via_tuple(file_id) do
+    {:via, Registry, {Backend.Files.FileRegistry, file_id}}
+  end
+
+  # Callbacks
+  def init(file_id) do
+    # Загружаем файл из БД при запуске
+    file = Files.get_file(file_id)
+    {:ok, %{file: file, timer: reset_timer(nil)}}
+  end
+
+  def handle_call({:update_content, new_content}, _from, %{file: file, timer: timer} = state) do
+    new_file = %{file | content: new_content}
+    {:reply, :ok, %{state | file: new_file, timer: reset_timer(timer)}}
+  end
+
+  def handle_info(:timeout, %{file: file} = state) do
+    # Сохраняем в БД перед завершением
+    Files.save_file(file)
+    {:stop, :normal, state}
+  end
+
+  defp reset_timer(timer) do
+    # Отменяем старый таймер, если он существует
+    if timer, do: Process.cancel_timer(timer)
+    # Устанавливаем новый таймер
+    Process.send_after(self(), :timeout, @timeout)
+  end
+end
diff --git a/lib/backend/files/file_registry.ex b/lib/backend/files/file_registry.ex
new file mode 100644
index 0000000..e8771f2
--- /dev/null
+++ b/lib/backend/files/file_registry.ex
@@ -0,0 +1,23 @@
+defmodule Backend.Files.FileRegistry do
+  @moduledoc """
+  Registy used for looking for active file processes pids
+  """
+
+  def start_link do
+    IO.puts("Starting file registry")
+
+    Registry.start_link(name: __MODULE__, keys: :unique)
+  end
+
+  def via_tuple(key) do
+    {:via, Registry, {__MODULE__, key}}
+  end
+
+  def child_spec(_) do
+    Supervisor.child_spec(
+      Registry,
+      id: __MODULE__,
+      start: {__MODULE__, :start_link, []}
+    )
+  end
+end
diff --git a/lib/backend/files/files.ex b/lib/backend/files/files.ex
index 4ad5649..9e88272 100644
--- a/lib/backend/files/files.ex
+++ b/lib/backend/files/files.ex
@@ -16,9 +16,13 @@ defmodule Backend.Files do
   end
 
   def save_file(file) do
+    # Это сделано специально, так как без обнуления контента cast думает, что ничего не изменилось
+    content = file.content
+    file = %{file | content: ""}
+
     file
-    |> File.changeset(%{})
-    |> Repo.update()
+    |> File.changeset(%{content: content})
+    |> Repo.update!()
   end
 
   def delete_file(file) do
diff --git a/lib/backend_web/channels/room_channel.ex b/lib/backend_web/channels/room_channel.ex
index 57b3d32..02861a8 100644
--- a/lib/backend_web/channels/room_channel.ex
+++ b/lib/backend_web/channels/room_channel.ex
@@ -2,14 +2,25 @@ defmodule BackendWeb.FileChannel do
   @moduledoc """
   Websocket channel for each .mds file
   """
+  alias Backend.Files
+  alias Backend.Files.FileManager
   use Phoenix.Channel
 
-  def join("file:" <> _room_id, _params, socket) do
-    {:ok, socket}
+  def join("file:" <> file_id, _params, socket) do
+    case Files.get_file(file_id) do
+      nil -> {:error, %{reason: "File with id " <> file_id <> " does not exist"}}
+      _ -> {:ok, assign(socket, :file_id, file_id)}
+    end
   end
 
   def handle_in("edit", %{"content" => content}, socket) do
-    # Рассылка обновлений всем клиентам
+    # Получаем file_id из socket.assigns
+    file_id = socket.assigns.file_id
+
+    # Вызываем FileManager для обновления содержимого файла
+    FileManager.update_file_content(file_id, content)
+
+    # Рассылаем обновления всем клиентам
     broadcast!(socket, "update", %{content: content})
     {:noreply, socket}
   end
diff --git a/priv/repo/migrations/20241129212656_add_file.exs b/priv/repo/migrations/20241129212656_add_file.exs
index 0f9d2e0..ec46f1c 100644
--- a/priv/repo/migrations/20241129212656_add_file.exs
+++ b/priv/repo/migrations/20241129212656_add_file.exs
@@ -4,7 +4,7 @@ defmodule Backend.Repo.Migrations.AddFile do
   def change do
     create table(:files) do
       add :name, :string, null: false
-      add :content, :binary
+      add :content, :string
     end
   end
 end