refactor: simplify client id and client secret generation

lib/comfycamp/rand.ex

@@ -1,6 +1,9 @@
 defmodule Comfycamp.Rand do
+  @chars "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789" |> String.codepoints()
+
   def get_random_string(length) do
-    :crypto.strong_rand_bytes(length)
-    |> Base.url_encode64()
+    1..length
+    |> Enum.map(fn _i -> Enum.random(@chars) end)
+    |> Enum.join("")
   end
 end

lib/comfycamp/sso.ex

@@ -5,6 +5,7 @@ defmodule Comfycamp.SSO do
 
   import Ecto.Query, warn: false
   alias Comfycamp.Repo
+  alias Comfycamp.Rand
 
   alias Comfycamp.SSO.OIDCApp
 
@@ -50,7 +51,12 @@ defmodule Comfycamp.SSO do
 
   """
   def create_oidc_app(attrs \\ %{}) do
-    %OIDCApp{}
+    app = %OIDCApp{
+      client_id: Rand.get_random_string(20),
+      client_secret: Rand.get_random_string(32)
+    }
+
+    app
     |> OIDCApp.changeset(attrs)
     |> Repo.insert()
   end

lib/comfycamp/sso/oidc_app.ex

@@ -15,10 +15,8 @@ defmodule Comfycamp.SSO.OIDCApp do
   @doc false
   def changeset(oidc_app, attrs) do
     oidc_app
-    |> cast(attrs, [:name, :client_id, :client_secret, :enabled])
-    |> validate_required([:name, :client_id, :client_secret, :enabled])
-    |> validate_length(:name, min: 2)
-    |> validate_length(:client_id, min: 8)
-    |> validate_length(:client_secret, min: 12)
+    |> cast(attrs, [:name, :enabled])
+    |> validate_required([:name, :enabled])
+    |> validate_length(:name, min: 2, max: 48)
   end
 end

lib/comfycamp_web/controllers/oidc_app_controller.ex

@@ -3,7 +3,6 @@ defmodule ComfycampWeb.OIDCAppController do
 
   alias Comfycamp.SSO
   alias Comfycamp.SSO.OIDCApp
-  alias Comfycamp.Rand
 
   def index(conn, _params) do
     oidc_apps = SSO.list_oidc_apps()
@@ -14,10 +13,7 @@ defmodule ComfycampWeb.OIDCAppController do
   end
 
   def new(conn, _params) do
-    changeset = SSO.change_oidc_app(%OIDCApp{
-      client_id: Rand.get_random_string(20),
-      client_secret: Rand.get_random_string(32),
-    })
+    changeset = SSO.change_oidc_app(%OIDCApp{})
 
     conn
     |> put_layout(html: :admin)

lib/comfycamp_web/controllers/oidc_app_html/oidc_app_form.html.heex

@@ -3,8 +3,6 @@
     <.error :if={@changeset.action}>
       Oops, something went wrong! Please check the errors below.
     </.error>
-    <.input field={f[:client_id]} type="text" label="Client ID" readonly />
-    <.input field={f[:client_secret]} type="password" label="Client secret" readonly />
     <.input field={f[:name]} type="text" label="Name" />
     <.input field={f[:enabled]} type="checkbox" label="Enabled" />
     <:actions>

lib/comfycamp_web/controllers/oidc_app_html/show.html.heex

@@ -11,7 +11,7 @@
 
   <.list>
     <:item title="Name"><%= @oidc_app.name %></:item>
-    <:item title="Client"><%= @oidc_app.client_id %></:item>
+    <:item title="Client ID"><%= @oidc_app.client_id %></:item>
     <:item title="Client secret"><%= @oidc_app.client_secret %></:item>
     <:item title="Enabled"><%= @oidc_app.enabled %></:item>
   </.list>

test/comfycamp/sso_test.exs

@@ -31,8 +31,6 @@ defmodule Comfycamp.SSOTest do
       assert {:ok, %OIDCApp{} = oidc_app} = SSO.create_oidc_app(valid_attrs)
       assert oidc_app.enabled == true
       assert oidc_app.name == "some name"
-      assert oidc_app.client_id == "some client_id"
-      assert oidc_app.client_secret == "some client_secret"
     end
 
     test "create_oidc_app/1 with invalid data returns error changeset" do
@@ -52,8 +50,6 @@ defmodule Comfycamp.SSOTest do
       assert {:ok, %OIDCApp{} = oidc_app} = SSO.update_oidc_app(oidc_app, update_attrs)
       assert oidc_app.enabled == false
       assert oidc_app.name == "some updated name"
-      assert oidc_app.client_id == "some updated client_id"
-      assert oidc_app.client_secret == "some updated client_secret"
     end
 
     test "update_oidc_app/2 with invalid data returns error changeset" do