defmodule Mailer do
  require Logger

  @url "api_url"
  @email_from "email"

  # def send(template_id, subject, dynamic_template_data, to, env)
  #     when env in [:dev, :review, :staging],
  #     do: send(template_id, subject, dynamic_template_data, "email_from")

  def send(template_id, subject, dynamic_template_data, to, _env),
    do: send(template_id, subject, dynamic_template_data, to)

  def send(template_id, subject, dynamic_template_data, to) do
    @url
    |> HTTPoison.post(body(template_id, subject, dynamic_template_data, to), headers())
    |> process_response()
  end

  def body(template_id, subject, dynamic_template_data, to) do
    Jason.encode!(%{
      subject: subject,
      from: %{email: @email_from},
      personalizations: [
        %{
          to: [%{email: to}],
          dynamic_template_data: dynamic_template_data
        }
      ],
      template_id: template_id
    })
  end

  defp headers do
    [
      {"Content-Type", "application/json"},
      {"Authorization", "Bearer #{Application.get_env(:app, :sendgrid_api_key)}"}
    ]
  end

  defp process_response(
         {:ok, %HTTPoison.Response{status_code: 200, body: body, headers: headers}}
       ) do
    {:ok, body, headers}
  end

  defp process_response(
         {:ok, %HTTPoison.Response{status_code: 202, body: body, headers: headers}}
       ) do
    {:ok, body, headers}
  end

  defp process_response({:ok, %HTTPoison.Response{status_code: code, body: body}}) do
    Sentry.capture_message(
      "[Sengrid#process_response] status_code: #{code}",
      extra: %{extra: "body: #{body}"}
    )

    {:error, "HttpError Sendgrid. Code: #{code}"}
  end

  defp process_response({:error, %HTTPoison.Error{reason: reason}}) do
    Sentry.capture_message(
      "[Sengrid#process_response]",
      extra: %{extra: "body: #{reason}"}
    )

    {:error, "HttpError Sendgrid. Reason: #{reason}"}
  end

  defp process_response(_) do
    {:error, "Unknown error happened"}
  end
end