defmodule Mv.MailerTest do
  @moduledoc """
  Unit tests for Mv.Mailer, in particular send_test_email/1.

  Uses Swoosh.Adapters.Test (configured in test.exs); no real SMTP. Asserts
  success/error contract and that one test email is sent on success.
  """
  use Mv.DataCase, async: true

  import Swoosh.TestAssertions

  alias Mv.Mailer

  describe "send_test_email/1" do
    test "returns {:ok, email} and sends one email with expected subject/body when successful" do
      to_email = "test-#{System.unique_integer([:positive])}@example.com"

      assert {:ok, _email} = Mailer.send_test_email(to_email)

      assert_email_sent(fn email ->
        to_addresses = Enum.map(email.to, &elem(&1, 1))
        subject = email.subject || ""
        body = email.html_body || email.text_body || ""

        to_email in to_addresses and
          (String.contains?(subject, "Test") or String.contains?(body, "test"))
      end)
    end

    test "returns {:error, reason} for invalid email address" do
      result = Mailer.send_test_email("not-an-email")
      assert {:error, _reason} = result
    end

    test "uses mail_from as sender" do
      to_email = "recipient-#{System.unique_integer([:positive])}@example.com"
      assert {:ok, _} = Mailer.send_test_email(to_email)

      assert_email_sent(fn email ->
        {_name, from_email} = Mailer.mail_from()
        from_addresses = Enum.map(email.from, &elem(&1, 1))
        from_email in from_addresses
      end)
    end
  end
end