Implement internal token interface

lib/hostas/token.ex

@@ -1,6 +1,7 @@
 defmodule Hostas.Token do
   use Ecto.Schema
   import Ecto.Changeset
+  import Ecto.Query, only: [from: 2]
 
   alias Hostas.Token
   alias Hostas.Repo
@@ -11,12 +12,11 @@ defmodule Hostas.Token do
   @duration_days 30
 
   schema "tokens" do
-    field :denizen_id, :integer
     field :expires, :utc_datetime
     field :token, :string
 
     # Link tokens to denizens
-    belongs_to :denizens, Hostas.Denizen
+    belongs_to :denizen, Hostas.Denizen
 
     timestamps()
   end
@@ -24,8 +24,8 @@ defmodule Hostas.Token do
   @doc false
   def changeset(token, attrs) do
     token
-    |> cast(attrs, [:denizen_id, :expires])
-    |> validate_required([:denizen_id, :expires])
+    |> cast(attrs, [:denizen_id, :expires, :token])
+    |> validate_required([:denizen_id, :expires, :token])
   end
 
   @doc """
@@ -46,4 +46,41 @@ defmodule Hostas.Token do
     # Register the token
     Repo.insert(changeset(%Token{}, %{denizen_id: denizen_id, token: token, expires: expiry}))
   end
+
+  @doc """
+  Returns {:ok, struct} if the token hasn't expired. Otherwise, returns :expired
+  """
+  def get(key) do
+    struct = Repo.one!(from t in Token, where: t.token == ^key)
+
+    unless expired?(struct) do
+      {:ok, struct}
+    else
+      :expired
+    end
+  end
+
+  @doc """
+  Returns true if the given token has expired
+  """
+  def expired?(%Token{expires: expiry}) do
+    {:ok, now} = DateTime.now("Etc/UTC")
+    case DateTime.compare(expiry, now) do
+      :lt -> true
+      _ -> false
+    end
+  end
+
+  def expired?(token) when is_binary(token) do
+    expired?(Repo.one(from t in Token, where: t.token == ^token))
+  end
+
+  @doc """
+  Deletes a token. Does nothing if the token doesn't exist
+  """
+  def revoke(%Token{token: token}), do: revoke(token)
+  def revoke(token) when is_binary(token) do
+    Repo.delete_all(from t in Token, where: t.token == ^token)
+    :ok
+  end
 end

test/hostas/token_test.exs

@@ -0,0 +1,57 @@
+defmodule Hostas.TokenTest do
+  use Hostas.DataCase
+
+  # For testing with Ecto
+  import Ecto.Query, only: [from: 2]
+  alias Hostas.Repo
+  alias Hostas.Token
+
+  describe "token generation" do
+    test "succeeds" do
+      {:ok, struct} = Token.new(create_denizen().id)
+      assert Repo.one!(from t in Token, where: t.id == ^struct.id)
+    end
+  end
+
+  describe "check token expiry" do
+    test "by struct" do
+      {:ok, struct} = Token.new(create_denizen().id, -30)
+      assert Token.expired?(struct)
+    end
+
+    test "by key" do
+      {:ok, struct} = Token.new(create_denizen().id, -30)
+      assert Token.expired?(struct.token)
+    end
+  end
+
+  describe "fetch guarded against expiry" do
+    test "succeeds" do
+      {:ok, struct} = Token.new(create_denizen().id)
+      assert Token.get(struct.token) == {:ok, struct}
+    end
+
+    test "indicates the token is expired" do
+      {:ok, struct} = Token.new(create_denizen().id, -30)
+      assert Token.get(struct.token) == :expired
+    end
+
+    test "by key" do
+      {:ok, struct} = Token.new(create_denizen().id, -30)
+      assert Token.expired?(struct.token)
+    end
+  end
+
+  describe "revoke token" do
+    test "succeeds, given struct" do
+      {:ok, struct} = Token.new(create_denizen().id)
+      assert Token.revoke(struct) == :ok
+      assert Repo.one(from t in Token, where: t.token == ^struct.token) == nil
+    end
+
+    test "succeeds, given key" do
+      {:ok, struct} = Token.new(create_denizen().id)
+      assert Token.revoke(struct.token) == :ok
+    end
+  end
+end