defmodule Mv.MailerSmtpConfigTest do
  @moduledoc """
  Integration-style tests for `Mv.Mailer.smtp_config/0`.

  With the default test mailer adapter (`Swoosh.Adapters.Test`), `smtp_config/0`
  must return `[]` so per-send SMTP opts never bypass the test mailbox.

  Port 587 vs 465 / `:verify` in `sockopts` are covered by
  `Mv.Smtp.ConfigBuilderTest`; here we assert `smtp_config/0` wiring from
  `Mv.Config` when the mailer adapter is temporarily set to
  `Swoosh.Adapters.Local` (`async: false`, global Application env).

  Uses `Mv.DataCase` so `Mv.Config.smtp_username/0` and `smtp_password/0` (Settings
  fallback when ENV is unset) run under the SQL sandbox like the rest of the suite.
  """
  use Mv.DataCase, async: false

  alias Mv.Mailer

  defp clear_smtp_env do
    System.delete_env("SMTP_HOST")
    System.delete_env("SMTP_PORT")
    System.delete_env("SMTP_USERNAME")
    System.delete_env("SMTP_PASSWORD")
    System.delete_env("SMTP_PASSWORD_FILE")
    System.delete_env("SMTP_SSL")
  end

  describe "smtp_config/0 with Swoosh.Adapters.Test" do
    setup do
      previous = Application.get_env(:mv, Mv.Mailer)
      Application.put_env(:mv, Mv.Mailer, adapter: Swoosh.Adapters.Test)

      on_exit(fn ->
        Application.put_env(:mv, Mv.Mailer, previous)
      end)

      :ok
    end

    test "returns empty list when SMTP_* ENV is set so the test adapter is not overridden" do
      System.put_env("SMTP_HOST", "smtp.example.com")
      System.put_env("SMTP_PORT", "587")
      System.put_env("SMTP_SSL", "tls")
      on_exit(fn -> clear_smtp_env() end)

      assert Mailer.smtp_config() == []
    end
  end

  describe "smtp_config/0 with a non-Test mailer adapter" do
    setup do
      previous = Application.get_env(:mv, Mv.Mailer)
      Application.put_env(:mv, Mv.Mailer, adapter: Swoosh.Adapters.Local)

      on_exit(fn ->
        Application.put_env(:mv, Mv.Mailer, previous)
      end)

      :ok
    end

    test "port 587 (TLS): does not include :verify in sockopts so gen_tcp:connect does not crash" do
      System.put_env("SMTP_HOST", "smtp.example.com")
      System.put_env("SMTP_PORT", "587")
      System.put_env("SMTP_SSL", "tls")
      on_exit(fn -> clear_smtp_env() end)

      config = Mailer.smtp_config()

      assert config != [],
             "expected non-empty config when SMTP_HOST is set and adapter is not Test"

      sockopts = Keyword.get(config, :sockopts, [])

      refute Keyword.has_key?(sockopts, :verify),
             "for 587 gen_tcp is used first; sockopts must not contain :verify"
    end

    test "port 465 (SSL): includes :verify in sockopts so initial ssl:connect accepts verify mode" do
      System.put_env("SMTP_HOST", "smtp.example.com")
      System.put_env("SMTP_PORT", "465")
      System.put_env("SMTP_SSL", "ssl")
      on_exit(fn -> clear_smtp_env() end)

      config = Mailer.smtp_config()
      assert config != []
      sockopts = Keyword.get(config, :sockopts, [])

      assert Keyword.has_key?(sockopts, :verify),
             "for 465 initial connection is ssl:connect; sockopts must contain :verify"

      assert Keyword.get(sockopts, :verify) in [:verify_none, :verify_peer]
    end

    test "builds TLS mode for port 587 (STARTTLS)" do
      System.put_env("SMTP_HOST", "smtp.example.com")
      System.put_env("SMTP_PORT", "587")
      System.put_env("SMTP_SSL", "tls")
      on_exit(fn -> clear_smtp_env() end)

      config = Mailer.smtp_config()

      assert config != []
      assert Keyword.get(config, :tls) == :always
      assert Keyword.get(config, :ssl) == false
    end

    test "builds SSL mode for port 465 (implicit SSL)" do
      System.put_env("SMTP_HOST", "smtp.example.com")
      System.put_env("SMTP_PORT", "465")
      System.put_env("SMTP_SSL", "ssl")
      on_exit(fn -> clear_smtp_env() end)

      config = Mailer.smtp_config()

      assert config != []
      assert Keyword.get(config, :ssl) == true
      assert Keyword.get(config, :tls) == :never
    end
  end
end