require 'aws-sdk-ses'

module Eco
  module API
    module Common
      module Session
        class Mailer

          # @param enviro [Eco::API::Common::Session::Environment]
          def initialize (enviro:)
            raise "Required Environment object (enviro:). Given: #{enviro}" if enviro && !enviro.is_a?(Eco::API::Common::Session::Environment)
            @enviro = enviro
          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(to: nil, subject:, body:, cc: nil, bcc: nil)
            ses.send_email(
              destination: fetch_destination(to: to, cc: cc, bcc: bcc),
              source:  fetch_from,
              message: {
                subject: {
                  charset: "UTF-8",
                  data: subject,
                },
                body: {
                  # NOTE - html: will let you send html instead
                  # you can use both at once if you like
                  text: {
                    charset: "UTF-8",
                    data: body
                  }
                }
              }
            ).tap do |response|
              logger.debug("Sent email to #{to} (MessageId: #{response.message_id})")
            end
          end

          private

          def ses
            begin
              @ses ||= Aws::SES::Client.new(
                access_key_id:     fetch_access_key_id,
                secret_access_key: fetch_secret_access_key,
                region:            fetch_region
              )
            rescue Exception => e
              logger.error("Trying to send an email with wrong email configuration: #{e}")
            end
            @ses
          end

          def logger
            @enviro&.logger || ::Logger.new(IO::NULL)
          end

          def config
            @enviro.config || {}
          end

          def fetch_destination(to: nil, cc: nil, bcc: nil)
            cc_to  = [cc].flatten.compact.uniq
            bcc_to = [bcc].flatten.compact.uniq
            { to_addresses: [fetch_to(to)].flatten }.tap do |dest|
              dest.merge!(cc_addresses: cc_to) unless cc_to.empty?
              dest.merge!(bcc_addresses: bcc_to) unless bcc_to.empty?
            end
          end

          def fetch_to(value = nil)
            value || config.mailer.to
          end

          def fetch_from(value = nil)
            value || config.mailer.from
          end

          def fetch_access_key_id
            config.mailer.access_key_id || ENV['AWS_ACCESS_KEY_ID']
          end

          def fetch_secret_access_key
            config.mailer.secret_access_key || ENV['AWS_SECRET_ACCESS_KEY']
          end

          def fetch_region
            config.mailer.region || ENV['AWS_REGION']
          end

          def fetch_server
            config.mailer.server
          end

          def fetch_message_id_domain
            config.mailer.message_id_domain
          end

        end
      end
    end
  end
end