[Housekeeping] Refactor settings model (#165)

* [WIP] renamed current settings module and tables to have backup suffix

* Created new settings table, schema, and context

* Migrated from old settings module to new one

* Removed settings backup modules

* Added some tests and docs

lib/pinchflat/boot/pre_job_startup_tasks.ex

@@ -65,8 +65,6 @@ defmodule Pinchflat.Boot.PreJobStartupTasks do
   defp apply_default_settings do
     {:ok, yt_dlp_version} = CommandRunner.version()
 
-    Settings.fetch!(:onboarding, true)
-    Settings.fetch!(:pro_enabled, false)
-    Settings.set!(:yt_dlp_version, yt_dlp_version)
+    Settings.set(yt_dlp_version: yt_dlp_version)
   end
 end

lib/pinchflat/settings/setting.ex

@@ -1,24 +1,32 @@
 defmodule Pinchflat.Settings.Setting do
   @moduledoc """
-  A Setting is a key-value pair with a datatype used to track user-level settings.
+  The Setting schema.
   """
 
   use Ecto.Schema
   import Ecto.Changeset
 
-  schema "settings" do
-    field :name, :string
-    field :value, :string
-    field :datatype, Ecto.Enum, values: ~w(boolean string integer float)a
+  @allowed_fields [
+    :onboarding,
+    :pro_enabled,
+    :yt_dlp_version
+  ]
 
-    timestamps(type: :utc_datetime)
+  @required_fields ~w(
+    onboarding
+    pro_enabled
+  )a
+
+  schema "settings" do
+    field :onboarding, :boolean, default: true
+    field :pro_enabled, :boolean, default: false
+    field :yt_dlp_version, :string
   end
 
   @doc false
   def changeset(setting, attrs) do
     setting
-    |> cast(attrs, [:name, :value, :datatype])
-    |> validate_required([:name, :value, :datatype])
-    |> unique_constraint([:name])
+    |> cast(attrs, @allowed_fields)
+    |> validate_required(@required_fields)
   end
 end

lib/pinchflat/settings/settings.ex

@@ -2,94 +2,63 @@ defmodule Pinchflat.Settings do
   @moduledoc """
   The Settings context.
   """
-
   import Ecto.Query, warn: false
-  alias Pinchflat.Repo
 
+  alias Pinchflat.Repo
   alias Pinchflat.Settings.Setting
 
   @doc """
-  Returns the list of settings.
+  Returns the only setting record. It _should_ be impossible
+  to create or delete this record, so it's assertive about
+  assuming it's the only one.
 
-  Returns [%Setting{}, ...]
+  Returns %Setting{}
   """
-  def list_settings do
-    Repo.all(Setting)
+  def record do
+    Setting
+    |> limit(1)
+    |> Repo.one()
   end
 
   @doc """
-  Creates or updates a setting, returning the parsed value.
-  Raises if an unsupported datatype is used. Optionally allows
-  specifying the datatype.
+  Updates a setting, returning the new value.
+  Is setup to take a keyword list argument so you
+  can call it like `Settings.set(onboarding: true)`
 
-  Returns value in type of `Ecto.Enum.mappings(Setting, :datatype)`
+  Returns {:ok, value} | {:error, :invalid_key} | {:error, %Ecto.Changeset{}}
   """
-  def set!(name, value) do
-    set!(name, value, infer_datatype(value))
-  end
-
-  def set!(name, value, datatype) do
-    # Only create if doesn't exist
-    case Repo.get_by(Setting, name: to_string(name)) do
-      nil -> create_setting!(name, value, datatype)
-      setting -> update_setting!(setting, value, datatype)
+  def set([{attr, value}]) do
+    record()
+    |> Setting.changeset(%{attr => value})
+    |> Repo.update()
+    |> case do
+      {:ok, %{^attr => _}} -> {:ok, value}
+      {:ok, _} -> {:error, :invalid_key}
+      {:error, changeset} -> {:error, changeset}
     end
   end
 
   @doc """
-  Gets the parsed value of a setting. Raises if the setting does not exist.
+  Gets the value of a setting.
 
-  Returns value in type of `Ecto.Enum.mappings(Setting, :datatype)`
+  Returns {:ok, value} | {:error, :invalid_key}
+  """
+  def get(name) do
+    case Map.fetch(record(), name) do
+      {:ok, value} -> {:ok, value}
+      :error -> {:error, :invalid_key}
+    end
+  end
+
+  @doc """
+  Gets the value of a setting, raising if it doesn't exist.
+
+  Returns value
   """
   def get!(name) do
-    Setting
-    |> Repo.get_by!(name: to_string(name))
-    |> read_setting()
-  end
-
-  @doc """
-  Attempts to find a setting by name or creates a setting with value
-  if one doesn't exist, returning the parsed value. Optionally allows
-  specifying the datatype.
-
-  Returns value in type of `Ecto.Enum.mappings(Setting, :datatype)`
-  """
-  def fetch!(name, value) do
-    fetch!(name, value, infer_datatype(value))
-  end
-
-  def fetch!(name, value, datatype) do
-    case Repo.get_by(Setting, name: to_string(name)) do
-      nil -> create_setting!(name, value, datatype)
-      setting -> read_setting(setting)
+    case get(name) do
+      {:ok, value} -> value
+      {:error, _} -> raise "Setting `#{name}` not found"
     end
   end
-
-  defp change_setting(setting, attrs) do
-    Setting.changeset(setting, attrs)
-  end
-
-  defp create_setting!(name, value, datatype) do
-    %Setting{}
-    |> change_setting(%{name: to_string(name), value: to_string(value), datatype: datatype})
-    |> Repo.insert!()
-    |> read_setting()
-  end
-
-  defp update_setting!(setting, value, datatype) do
-    setting
-    |> change_setting(%{value: to_string(value), datatype: datatype})
-    |> Repo.update!()
-    |> read_setting()
-  end
-
-  defp read_setting(%{value: value, datatype: :string}), do: value
-  defp read_setting(%{value: value, datatype: :boolean}), do: value in ["true", "t", "1"]
-  defp read_setting(%{value: value, datatype: :integer}), do: String.to_integer(value)
-  defp read_setting(%{value: value, datatype: :float}), do: String.to_float(value)
-
-  defp infer_datatype(value) when is_boolean(value), do: :boolean
-  defp infer_datatype(value) when is_integer(value), do: :integer
-  defp infer_datatype(value) when is_float(value), do: :float
-  defp infer_datatype(value) when is_binary(value), do: :string
 end