init: inital commit

lib/localiser/domain/schema/user.ex

@@ -0,0 +1,28 @@
+defmodule Localiser.Domain.Schema.User do
+  use Ecto.Schema
+  import Ecto.Changeset
+
+  schema "users" do
+    field :username, :string
+    field :password_hash, :string, redact: true
+    field :password, :string, virtual: true, redact: true
+
+    timestamps(type: :utc_datetime)
+  end
+
+  @doc false
+  def changeset(user, attrs) do
+    user
+    |> cast(attrs, [:username, :password])
+    |> validate_required([:username, :password])
+    |> validate_length(:password, min: 8)
+    |> unique_constraint(:username)
+    |> hash_password()
+  end
+
+  defp hash_password(%Ecto.Changeset{valid?: true, changes: %{password: pw}} = changeset) do
+    put_change(changeset, :password_hash, Argon2.hash_pwd_salt(pw))
+  end
+
+  defp hash_password(changeset), do: changeset
+end