infinitered · danielberkompas · Dec 11, 2017 · Dec 11, 2017 · Dec 11, 2017 · Dec 11, 2017
diff --git a/lib/authentication/authentication.ex b/lib/authentication/authentication.ex
@@ -1,37 +1,37 @@
 defmodule Authority.Authentication do
   @type id :: any
-  @type credential :: any
+  @type credential :: {id, any} | any
+  @type opts :: Keyword.t()
 
-  @callback authenticate(credential) :: {:ok, any} | {:error, term}
-  @callback authenticate(id, credential) :: {:ok, any} | {:error, term}
+  @callback authenticate(credential, opts) :: {:ok, any} | {:error, term}
 
   @doc false
-  def authenticate(%{store: store}, credential) do
-    with {:ok, identity} <- store.identify(credential),
-         :ok <- store.validate(credential, identity) do
+  def authenticate(%{store: store}, {identifier, credential}, opts) do
+    with {:ok, identity} <- store.identify(identifier, opts),
+         :ok <- store.validate(credential, identity, opts) do
       {:ok, identity}
     end
   end
 
   @doc false
-  def authenticate(%{store: store}, identifier, credential) do
-    with {:ok, identity} <- store.identify(identifier),
-         :ok <- store.validate(credential, identity) do
+  def authenticate(%{store: store}, credential, opts) do
+    with {:ok, identity} <- store.identify(credential, opts),
+         :ok <- store.validate(credential, identity, opts) do
       {:ok, identity}
     end
   end
 
   defmacro __using__(config) do
     quote do
       @behaviour Authority.Authentication
-      @config Enum.into(unquote(config), %{})
+      @__authentication__ Enum.into(unquote(config), %{})
 
-      def authenticate(credential) do
-        Authority.Authentication.authenticate(@config, credential)
+      def authenticate(credential, opts \\ []) do
+        Authority.Authentication.authenticate(@__authentication__, credential, opts)
       end
 
-      def authenticate(identifier, credential) do
-        Authority.Authentication.authenticate(@config, identifier, credential)
+      def __authentication__ do
+        @__authentication__
       end
 
       defoverridable Authority.Authentication

diff --git a/lib/authentication/store.ex b/lib/authentication/store.ex
@@ -1,7 +1,9 @@
 defmodule Authority.Authentication.Store do
+  @type opts :: Keyword.t()
+  @type id :: any
   @type identity :: any
   @type credential :: any
 
-  @callback identify(any) :: {:ok, identity} | {:error, term}
-  @callback validate(credential, identity) :: :ok | {:error, term}
+  @callback identify(id, opts) :: {:ok, identity} | {:error, term}
+  @callback validate(credential, identity, opts) :: :ok | {:error, term}
 end
diff --git a/lib/authentication/stores/ecto_store.ex b/lib/authentication/stores/ecto_store.ex
diff --git a/lib/exchange/exchange.ex b/lib/exchange/exchange.ex
@@ -0,0 +1,51 @@
+defmodule Authority.Exchange do
+  # MyModule.exchange("user@email.com", for: MyApp.Token, context: :recovery)
+  # MyModule.Exchange.exchange(OAuthCode{provider: :facebook, code: "..."}, for: MyApp.Token, context: :identity)
+  # MyModule.Exchange.exchange({"user@email.com", "password"}, for: MyApp.Token, context: :identity)
+
+  alias Authority.Authentication
+
+  @type opts :: Keyword.t()
+
+  @callback exchange(Authentication.credential()) ::
+              {:ok, Authentication.credential()}
+              | {:error, term}
+
+  @callback exchange(Authentication.credential(), opts) ::
+              {:ok, Authentication.credential()}
+              | {:error, term}
+
+  @doc false
+  def exchange(%{store: store, authentication: authentication}, credential, opts) do
+    with {:ok, identity} <- authentication.authenticate(credential, opts) do
+      store.exchange(identity, opts)
+    end
+  end
+
+  @doc false
+  def exchange(
+        %{store: store, authentication: authentication},
+        identifier,
+        credential,
+        opts
+      ) do
+    with {:ok, identity} <- authentication.authenticate(identifier, credential, opts) do
+      store.exchange(identity, opts)
+    end
+  end
+
+  defmacro __using__(config) do
+    quote do
+      @behaviour Authority.Exchange
+      @__exchange__ Enum.into(unquote(config), %{})
+
+      def exchange(credential, opts \\ []) do
+        Authority.Exchange.exchange(@__exchange__, credential, opts)
+      end
+
+      def __exchange__ do
+        @__exchange__
+      end
+    end
+  end
+end
diff --git a/lib/exchange/store.ex b/lib/exchange/store.ex
@@ -0,0 +1,9 @@
+defmodule Authority.Exchange.Store do
+  alias Authority.Authentication
+
+  @type opts :: Keyword.t()
+
+  @callback exchange(Authentication.identity(), opts) ::
+              {:ok, Authentication.credential()}
+              | {:error, term}
+end