From 846d0fb16de3a343400e8b8ff96731a606b4271c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Moritz=20B=C3=B6hme?= <mail@moritzboeh.me>
Date: Wed, 7 Aug 2024 08:21:57 +0200
Subject: [PATCH] feat: add supervisor

---
 lib/todo/cache.ex           | 11 +++++++----
 lib/todo/database.ex        |  7 ++++---
 lib/todo/database_worker.ex |  3 ++-
 lib/todo/server.ex          |  2 ++
 lib/todo/system.ex          | 14 ++++++++++++++
 5 files changed, 29 insertions(+), 8 deletions(-)
 create mode 100644 lib/todo/system.ex

diff --git a/lib/todo/cache.ex b/lib/todo/cache.ex
index 9e29fc6..b774a1c 100644
--- a/lib/todo/cache.ex
+++ b/lib/todo/cache.ex
@@ -3,7 +3,10 @@ defmodule Todo.Cache do
 
   @impl GenServer
   def init(_init_args) do
+    IO.puts("Starting #{__MODULE__}")
+
     Todo.Database.start()
+
     {:ok, %{}}
   end
 
@@ -22,11 +25,11 @@ defmodule Todo.Cache do
     end
   end
 
-  def start() do
-    GenServer.start(__MODULE__, nil)
+  def start_link(_) do
+    GenServer.start_link(__MODULE__, nil, name: __MODULE__)
   end
 
-  def server_process(pid, name) do
-    GenServer.call(pid, {:server_process, name})
+  def server_process(name) do
+    GenServer.call(__MODULE__, {:server_process, name})
   end
 end
diff --git a/lib/todo/database.ex b/lib/todo/database.ex
index b67dfb8..2660223 100644
--- a/lib/todo/database.ex
+++ b/lib/todo/database.ex
@@ -19,6 +19,8 @@ defmodule Todo.Database do
 
   @impl GenServer
   def init(_) do
+    IO.puts("Starting #{__MODULE__}")
+
     File.mkdir_p!(@db_folder)
 
     {:ok, nil, {:continue, :init}}
@@ -36,14 +38,13 @@ defmodule Todo.Database do
       end)
       |> Map.new()
 
-    IO.inspect(workers)
     {:noreply, workers}
   end
 
   @impl GenServer
   def handle_cast({:store, key, data}, workers) do
     workers
-    |> get_worker(key)
+    |> choose_worker(key)
     |> DatabaseWorker.store(key, data)
 
     {:noreply, workers}
@@ -53,7 +54,7 @@ defmodule Todo.Database do
   def handle_call({:get, key}, _, workers) do
     data =
       workers
-      |> get_worker(key)
+      |> choose_worker(key)
       |> DatabaseWorker.get(key)
 
     {:reply, data, workers}
diff --git a/lib/todo/database_worker.ex b/lib/todo/database_worker.ex
index 8a2e265..4ad902a 100644
--- a/lib/todo/database_worker.ex
+++ b/lib/todo/database_worker.ex
@@ -15,6 +15,8 @@ defmodule Todo.DatabaseWorker do
 
   @impl GenServer
   def init(db_folder) do
+    IO.puts("Starting #{__MODULE__} with db folder #{db_folder}.")
+
     {:ok, db_folder}
   end
 
@@ -44,5 +46,4 @@ defmodule Todo.DatabaseWorker do
   def file_name({db_folder, key}) do
     Path.join(db_folder, to_string(key))
   end
-
 end
diff --git a/lib/todo/server.ex b/lib/todo/server.ex
index 2688873..a881bc6 100644
--- a/lib/todo/server.ex
+++ b/lib/todo/server.ex
@@ -23,6 +23,8 @@ defmodule Todo.Server do
 
   @impl GenServer
   def init(name) do
+    IO.puts("Starting #{__MODULE__} for #{name}.")
+
     {:ok, {name, nil}, {:continue, :init}}
   end
 
diff --git a/lib/todo/system.ex b/lib/todo/system.ex
new file mode 100644
index 0000000..c9ff243
--- /dev/null
+++ b/lib/todo/system.ex
@@ -0,0 +1,14 @@
+defmodule Todo.System do
+  use Supervisor
+
+  def start_link do
+    Supervisor.start_link(__MODULE__, nil)
+  end
+
+  def init(_) do
+    Supervisor.init(
+      [Todo.Cache],
+      strategy: :one_for_one
+    )
+  end
+end