From caf3535e745ff249531230c31aefba6e4076f4b0 Mon Sep 17 00:00:00 2001
From: SphericalKat <amolele@gmail.com>
Date: Fri, 20 Aug 2021 03:00:17 +0530
Subject: [PATCH] feat(mailer): send mail asynchronously

Signed-off-by: SphericalKat <amolele@gmail.com>
---
 config/prod.exs                      | 26 ----------
 config/releases.exs                  | 25 +++++++++
 lib/ketbin/accounts/user_notifier.ex | 76 ++++++++++++++++------------
 3 files changed, 70 insertions(+), 57 deletions(-)

diff --git a/config/prod.exs b/config/prod.exs
index a30f6ff..3453716 100644
--- a/config/prod.exs
+++ b/config/prod.exs
@@ -16,32 +16,6 @@ config :ketbin, KetbinWeb.Endpoint,
 # Do not print debug messages in production
 config :logger, level: :info
 
-smtp_relay =
-  System.get_env("SWOOSH_SMTP_RELAY") ||
-    raise """
-    environment variable SWOOSH_SMTP_RELAY is missing.
-    """
-username =
-  System.get_env("SWOOSH_USERNAME") ||
-    raise """
-    environment variable SWOOSH_USERNAME is missing.
-    """
-password =
-  System.get_env("SWOOSH_PASSWORD") ||
-    raise """
-    environment variable SWOOSH_PASSWORD is missing.
-    """
-
-# configure mailer
-config :ketbin, Ketbin.Mailer,
-  adapter: Swoosh.Adapters.SMTP,
-  relay: smtp_relay,
-  username: username,
-  password: password,
-  tls: :always,
-  auth: :always,
-  port: 587
-
 # ## SSL Support
 #
 # To get SSL working, you will need to add the `https` key
diff --git a/config/releases.exs b/config/releases.exs
index 35c4ada..d82088a 100644
--- a/config/releases.exs
+++ b/config/releases.exs
@@ -33,6 +33,31 @@ config :ketbin, KetbinWeb.Endpoint,
   secret_key_base: secret_key_base,
   server: true
 
+  smtp_relay =
+    System.get_env("SWOOSH_SMTP_RELAY") ||
+      raise """
+      environment variable SWOOSH_SMTP_RELAY is missing.
+      """
+  username =
+    System.get_env("SWOOSH_USERNAME") ||
+      raise """
+      environment variable SWOOSH_USERNAME is missing.
+      """
+  password =
+    System.get_env("SWOOSH_PASSWORD") ||
+      raise """
+      environment variable SWOOSH_PASSWORD is missing.
+      """
+
+  # configure mailer
+  config :ketbin, Ketbin.Mailer,
+    adapter: Swoosh.Adapters.SMTP,
+    relay: smtp_relay,
+    username: username,
+    password: password,
+    tls: :always,
+    auth: :always,
+    port: 587
 # ## Using releases (Elixir v1.9+)
 #
 # If you are doing OTP releases, you need to instruct Phoenix
diff --git a/lib/ketbin/accounts/user_notifier.ex b/lib/ketbin/accounts/user_notifier.ex
index cb5987d..f123591 100644
--- a/lib/ketbin/accounts/user_notifier.ex
+++ b/lib/ketbin/accounts/user_notifier.ex
@@ -6,16 +6,18 @@ defmodule Ketbin.Accounts.UserNotifier do
   #   * Swoosh - https://hexdocs.pm/swoosh
   #   * Bamboo - https://hexdocs.pm/bamboo
   #
-  defp deliver(to, body) do
+  defp deliver(to, body, subject) do
     require Logger
     Logger.debug(body)
 
-    new()
-    |> to(to)
-    |> from("noreply@katb.in")
-    |> subject("Password reset requested")
-    |> text_body(body)
-    |> Ketbin.Mailer.deliver()
+    Task.start(fn ->
+      new()
+      |> to(to)
+      |> from({"Katbin", "noreply@katb.in"})
+      |> subject(subject)
+      |> text_body(body)
+      |> Ketbin.Mailer.deliver()
+    end)
 
     {:ok, %{to: to, body: body}}
   end
@@ -24,59 +26,71 @@ defmodule Ketbin.Accounts.UserNotifier do
   Deliver instructions to confirm account.
   """
   def deliver_confirmation_instructions(user, url) do
-    deliver(user.email, """
+    deliver(
+      user.email,
+      """
 
-    ==============================
+      ==============================
 
-    Hi #{user.email},
+      Hi #{user.email},
 
-    You can confirm your account by visiting the URL below:
+      You can confirm your account by visiting the URL below:
 
-    #{url}
+      #{url}
 
-    If you didn't create an account with us, please ignore this.
+      If you didn't create an account with us, please ignore this.
 
-    ==============================
-    """)
+      ==============================
+      """,
+      "Account confirmation"
+    )
   end
 
   @doc """
   Deliver instructions to reset a user password.
   """
   def deliver_reset_password_instructions(user, url) do
-    deliver(user.email, """
+    deliver(
+      user.email,
+      """
 
-    ==============================
+      ==============================
 
-    Hi #{user.email},
+      Hi #{user.email},
 
-    You can reset your password by visiting the URL below:
+      You can reset your password by visiting the URL below:
 
-    #{url}
+      #{url}
 
-    If you didn't request this change, please ignore this.
+      If you didn't request this change, please ignore this.
 
-    ==============================
-    """)
+      ==============================
+      """,
+      "Password reset requested"
+    )
   end
 
   @doc """
   Deliver instructions to update a user email.
   """
   def deliver_update_email_instructions(user, url) do
-    deliver(user.email, """
+    deliver(
+      user.email,
+      """
 
-    ==============================
+      ==============================
 
-    Hi #{user.email},
+      Hi #{user.email},
 
-    You can change your email by visiting the URL below:
+      You can change your email by visiting the URL below:
 
-    #{url}
+      #{url}
 
-    If you didn't request this change, please ignore this.
+      If you didn't request this change, please ignore this.
 
-    ==============================
-    """)
+      ==============================
+      """,
+      "Email update requested"
+    )
   end
 end