require_relative 'mailer/provider_base'
require_relative 'mailer/aws_provider'
require_relative 'mailer/sendgrid_provider'

class EcoRake
  module Utils
    # Mailer helper that uses `aws-sdk-ses` **gem** (`Aws::SES::Client`)
    # Several ENV vars should be configured for it to work (i.e. in the `.env` file):
    #   1. `MAILER_REGION`
    #   2. `MAILER_KEY_ID`
    #   3. `MAILER_ACCESS_KEY`
    #   4. `MAILER_FROM`
    class Mailer
      DEFAULT_PROVIDER = :sendgrid

      attr_reader :provider

      def initialize(provider: DEFAULT_PROVIDER)
        @provider = provider || DEFAULT_PROVIDER
      end

      # Sends an email
      # @param to [String] destination email address
      # @param subject [String] subject of the email
      # @param body [String] `html` or plain text message
      def mail(subject:, body:, to: nil, cc: nil, bcc: nil)
        return false unless (serv = service)

        unless serv.configured?
          msg  = "Mailer: You are missing configuration parameters "
          msg << "for '#{provider}'. Review your .env file"
          puts msg
          return false
        end

        serv.send_mail(
          subject: subject,
          body:    body,
          to:      to,
          cc:      cc,
          bcc:     bcc
        ).tap do |response|
          next unless response

          to_addr = serv.fetch_to(to)
          msg = "Sent email #{ProviderBase.to_desc(to: to_addr, cc: cc, bcc: bcc)}"
          puts msg
        end
      rescue StandardError => err
        msg  = "The mailer generated an exception:\n"
        msg << err.patch_full_message(trace_count: 15)
        puts msg
      end

      private

      def service
        case provider
        when :aws
          AwsProvider.new
        when :sendgrid
          SendgridProvider.new
        else
          puts "Unknown mail provider '#{provider}'"
          nil
        end
      end
    end
  end
end