From c793b46e53215af1a1f1181bfa57f5e224c909df Mon Sep 17 00:00:00 2001
From: KKlochko <KKlochko@protonmail.com>
Date: Wed, 9 Aug 2023 21:37:54 +0300
Subject: [PATCH] Add the authentication for API sing in.

---
 CHANGELOG.org                                     |  2 ++
 lib/link_shortener_web/auth/guardian.ex           | 15 +++++++++++++++
 .../controllers/fallback_controller.ex            |  6 ++++++
 3 files changed, 23 insertions(+)

diff --git a/CHANGELOG.org b/CHANGELOG.org
index 8b450b3..dcdffbe 100644
--- a/CHANGELOG.org
+++ b/CHANGELOG.org
@@ -57,3 +57,5 @@
     Add tests for UserController, Accounts, Generators.
 ** 0.8.0 <2023-08-08 Tue>
     Add the Web Authentication.
+** 0.8.1 <2023-08-09 Wed>
+    Add the authentication for API sing in.
diff --git a/lib/link_shortener_web/auth/guardian.ex b/lib/link_shortener_web/auth/guardian.ex
index 48e1bba..c53ec3c 100644
--- a/lib/link_shortener_web/auth/guardian.ex
+++ b/lib/link_shortener_web/auth/guardian.ex
@@ -2,6 +2,7 @@ defmodule LinkShortenerWeb.Auth.Guardian do
   use Guardian, otp_app: :link_shortener
 
   alias LinkShortener.Accounts
+  alias LinkShortener.Accounts.User
 
   def subject_for_token(user, _claims) do
     sub = to_string(user.id)
@@ -13,4 +14,18 @@ defmodule LinkShortenerWeb.Auth.Guardian do
     resource = Accounts.get_user!(id)
     {:ok,  resource}
   end
+
+  def authenticate(email, password) do
+    with user <- Accounts.get_user_by_email_and_password(email, password) do
+      case user do
+        %User{} -> create_token(user)
+        nil -> {:error, :unauthorized}
+      end
+    end
+  end
+
+  defp create_token(user) do
+    {:ok, token, _claims} = encode_and_sign(user)
+    {:ok, user, token}
+  end
 end
diff --git a/lib/link_shortener_web/controllers/fallback_controller.ex b/lib/link_shortener_web/controllers/fallback_controller.ex
index 5f25eb5..c1a87df 100644
--- a/lib/link_shortener_web/controllers/fallback_controller.ex
+++ b/lib/link_shortener_web/controllers/fallback_controller.ex
@@ -21,4 +21,10 @@ defmodule LinkShortenerWeb.FallbackController do
     |> put_view(LinkShortenerWeb.ErrorView)
     |> render(:"404")
   end
+
+  def call(conn, {:error, :unauthorized}) do
+    conn
+    |> put_status(:unauthorized)
+    |> render(LinkShortenerWeb.ErrorView, :"401")
+  end
 end