defmodule Rivet.Email do def mailer(), do: Application.get_env(:rivet_email, :mailer) defmacro __using__(opts) do quote location: :keep, bind_quoted: [opts: opts] do @from_key Keyword.get(opts, :from_key, [:email_from]) @user_model Keyword.get(opts, :user_model, Rivet.Ident.User) @email_model Keyword.get(opts, :email_model, Rivet.Ident.Email) @backend Keyword.get(opts, :backend) @configurator Keyword.get(opts, :configurator) require Logger @type email_model() :: @email_model.t() @type user_model() :: @user_model.t() @type user_id() :: String.t() @type email_recipient() :: email_model() | user_model() | user_id() def sendto(recips, template, assigns \\ [], configs \\ []) def sendto([], template, assigns, configs), do: Logger.error("Cannot send email to no recipients!", template: template) def sendto(recips, template, assigns, configs) do with {:ok, emails} <- get_emails(recips), {:ok, assigns} <- generate_assigns(assigns, configs) do send_all(emails, template, assigns, []) end end ########################################################################## defp send_all([recip | rest], template, assigns, out) when is_map(assigns) do case deliver(recip, template, assigns) do {:ok, result} -> send_all(rest, template, assigns, [result | out]) {:error, error} -> {:error, error, [out] |> Enum.reverse()} # other -> {:error, other, [out] |> Enum.reverse()} end end defp send_all([], _, _, out), do: {:ok, Enum.reverse(out)} ########################################################################## # future: for scale of thousands/second, add a read-through cache with Rivet lazy cache defp get_config(name), do: @configurator.get(name) defp reduce_load_config(name, {:ok, cfgs}) do case get_config(name) do {:ok, config} -> {:cont, {:ok, Map.merge(cfgs, config)}} {:error, :not_found} -> {:halt, {:error, "Email Configuration not found: #{name}"}} end end ########################################################################## def generate_assigns(assigns, configs) do with {:ok, cfgs} <- Enum.reduce_while(configs, {:ok, %{}}, &reduce_load_config/2) do assigns = Map.merge(cfgs, Map.new(assigns)) case get_in(assigns, @from_key) do nil -> {:error, "Sender email address is missing from assigns (@#{Enum.join(@from_key, ".")})"} [name, email] -> {:ok, put_in(assigns, @from_key, {name, email})} from -> {:ok, put_in(assigns, @from_key, from)} end end end ########################################################################## defp eex_lineno(trace) do Enum.reduce_while(trace, [], fn {:elixir_eval, :__FILE__, _, [file: 'nofile', line: line]}, stack -> {:halt, {:ok, "Line #{line}: ", stack}} line, stack -> {:cont, [line | stack]} end) |> case do {:ok, l, s} -> {l, s} x when is_list(x) -> IO.inspect(trace) Logger.warning("Could not find eval line in stack trace") {"", []} end end ########################################################################## @spec deliver(recipient :: any(), template :: atom(), assigns :: map()) :: {:ok, Swoosh.Email.t()} | {:error, term()} def deliver(%@email_model{} = recipient, template, assigns) do # the only magic value assigns = Map.put(assigns, :recipient, recipient) case template.generate(recipient, assigns) do {:ok, subject, body} -> Swoosh.Email.new(to: recipient.address, from: get_in(assigns, @from_key)) |> Swoosh.Email.subject(subject) |> Swoosh.Email.html_body("#{body}") |> Swoosh.Email.text_body(Rivet.Email.Template.html2text(body)) |> send_email() {:error, "Nothing found"} -> Logger.error("Cannot send email; template missing!", template: template) {:error, "template missing"} {:error, {%KeyError{} = e, trace}} -> {line, trace} = eex_lineno(trace) {:error, {:eval, "#{line}assigns key missing: #{e.key} #{e.message}", trace}} {:error, {%Protocol.UndefinedError{} = e, trace}} -> {line, trace} = eex_lineno(trace) {:error, {:eval, "#{line}Protocol error: #{inspect(e)}", trace}} {:error, {%UndefinedFunctionError{} = e, trace}} -> {line, trace} = eex_lineno(trace) {:error, {:eval, "#{line}undefined function: #{e.function}/#{e.arity} #{e.message}", trace}} # note for future reference: the EEX engine doesn't currently allow # for handling @assigns missing at the top level. There is a note to # have this be a future v2.0 thing, but until then we only get logged # messages, alas. other -> Logger.debug("error processing template", error: other) {:error, {:unknown, other}} end end ########################################################################## def send_email(%Swoosh.Email{to: [{_, eaddr} = addr], subject: subj} = email) do if Application.get_env(:rivet_email, :enabled) do if String.ends_with?("@example.com", eaddr) do {:error, :example_email} else Logger.debug("sending email", to: eaddr, from: email.from, subject: subj) @backend.deliver(email) end else Logger.warning("Email disabled, not sending message to #{inspect(addr)}", subject: subj) log_email(email) {:ok, "email disabled"} end end ########################################################################## def log_email(%Swoosh.Email{} = email) do Logger.warning(""" Subject: #{email.subject} --- html #{email.html_body} --- text #{email.text_body} """) end ########################################################################## # future: assigns can include verfied: true (or some way to only send to verified addresses) @spec get_emails(email_recipient() | list(email_recipient)) :: {:ok, list(email_model())} | {:error, String.t(), term()} def get_emails(recip, out \\ []) def get_emails([recip | recips], out) do with {:ok, email} <- get_email(recip) do get_emails(recips, [email | out]) else {:error, %{reason: :no_email, user: user}} -> {:error, "Unable to load email for user, cannot send email", user: user.id} err -> {:error, "Unable to find email", err} end end def get_emails([], out), do: {:ok, out} def get_emails(recip, out), do: get_emails([recip], out) ########################################################################## @spec get_email(email_recipient()) :: {:ok, email_model()} | {:error, reason :: any()} def get_email(%@email_model{} = email) do with {:ok, %@email_model{} = email} <- @email_model.preload(email, [:user]) do {:ok, email} end end # TODO: verified should be a settable option def get_email(%@user_model{} = user) do with {:ok, %@user_model{emails: emails}} <- @user_model.preload(user, [:emails]) do case Enum.find(emails, fn e -> e.verified end) do %@email_model{} = email -> {:ok, %@email_model{email | user: user}} _ -> with %@email_model{} = email <- List.first(emails) do {:ok, %@email_model{email | user: user}} else _ -> {:error, :no_email} end end end end def get_email(user_id) when is_binary(user_id) do with {:ok, user} <- @user_model.one(user_id) do get_email(user) end end end end end