[#923] OAuth: prototype of sign in / sign up with Twitter.

lib/pleroma/web/auth/pleroma_authenticator.ex

@@ -8,9 +8,9 @@ defmodule Pleroma.Web.Auth.PleromaAuthenticator do
 
   @behaviour Pleroma.Web.Auth.Authenticator
 
-  def get_user(%Plug.Conn{} = conn) do
-    %{"authorization" => %{"name" => name, "password" => password}} = conn.params
-
+  def get_user(%Plug.Conn{} = _conn, %{
+        "authorization" => %{"name" => name, "password" => password}
+      }) do
     with {_, %User{} = user} <- {:user, User.get_by_nickname_or_email(name)},
          {_, true} <- {:checkpw, Pbkdf2.checkpw(password, user.password_hash)} do
       {:ok, user}
@@ -20,6 +20,56 @@ defmodule Pleroma.Web.Auth.PleromaAuthenticator do
     end
   end
 
+  def get_user(%Plug.Conn{} = _conn, _params), do: {:error, :missing_credentials}
+
+  def get_or_create_user_by_oauth(
+        %Plug.Conn{assigns: %{ueberauth_auth: %{provider: provider, uid: uid} = auth}},
+        _params
+      ) do
+    user = User.get_by_auth_provider_uid(provider, uid)
+
+    if user do
+      {:ok, user}
+    else
+      info = auth.info
+      email = info.email
+      nickname = info.nickname
+
+      # TODO: FIXME: connect to existing (non-oauth) account (need a UI flow for that) / generate a random nickname?
+      email =
+        if email && User.get_by_email(email) do
+          nil
+        else
+          email
+        end
+
+      nickname =
+        if nickname && User.get_by_nickname(nickname) do
+          nil
+        else
+          nickname
+        end
+
+      new_user =
+        User.oauth_register_changeset(
+          %User{},
+          %{
+            auth_provider: to_string(provider),
+            auth_provider_uid: to_string(uid),
+            name: info.name,
+            bio: info.description,
+            email: email,
+            nickname: nickname
+          }
+        )
+
+      Pleroma.Repo.insert(new_user)
+    end
+  end
+
+  def get_or_create_user_by_oauth(%Plug.Conn{} = _conn, _params),
+    do: {:error, :missing_credentials}
+
   def handle_error(%Plug.Conn{} = _conn, error) do
     error
   end