random3.rb

require 'json'
require 'aws-sdk-dynamodb'
require 'mail'
require 'aws-sdk-ses'

def respond(event:, context:)
  event['Records'].each do |record|
    ses_client = Aws::SES::Client.new(region: 'us-west-2')
    db_client = Aws::DynamoDB::Client.new(region: 'us-west-2')

    state = get_state(record)
    status = get_status(record)
    destination_email = get_email(record)

    next unless destination_email

    user_settings = get_user_settings(db_client, destination_email)[:items].last

    case state
    when 6
      send_email(
        destination_email: destination_email,
        body: 'We just created a Purchase Order on your behalf!',
        subject: 'Congratulations! New Purchase Order Created!',
        ses_client: ses_client
      ) if can_send_success?(user_settings)
    when 7
      send_email(
        destination_email: destination_email,
        body: "A purchase order could not be created because #{status}",
        subject: 'Purchase Order Not created.',
        ses_client: ses_client
      ) if can_send_failure?(user_settings)
    when 8
      send_email(
        destination_email: destination_email,
        body: 'A Purchase Order could not be created because APM Help timed out trying to communicate with Appfolio.',
        subject: 'Purchase Order Not created.',
        ses_client: ses_client
      ) if can_send_failure?(user_settings)
    when 9
      send_email(
        destination_email: destination_email,
        body: 'A Purchase Order could not be created because we detected that you may have already sent this receipt before!',
        subject: 'Purchase Order Not created.',
        ses_client: ses_client
      ) if can_send_failure?(user_settings)
    else
      puts "record: #{record}"
    end
  end
end

def can_send_failure?(settings)
  settings[:receive_email_on_failure]
end

def can_send_success?(settings)
  settings[:receive_email_on_success]
end

def get_user_settings(client, user_email)
  begin
    all_settings = client.query({
      table_name: ENV['USER_TABLE_NAME'],
      key_condition_expression: '#email = :email',
      expression_attribute_names: {
        '#email' => 'email'
      },
      expression_attribute_values: {
        ':email' => user_email
      }
    })

    settings = all_settings[:items].last
  rescue => e
    default_settings
  end

  format_settings(settings)
end

def default_settings
  {
    receive_email_on_failure: false,
    receive_email_on_success: false
  }
end

def format_settings(settings)
  if settings.any?
    { 
      receive_email_on_failure: settings['receive_email_on_failure'],
      receive_email_on_success: settings['receive_email_on_success']
    }
  else
    default_settings
  end
end

def get_state(record)
  message(record)['current_state'].values.last.to_i
end

def get_status(record)
  message(record)['history'].values.flatten.last.values.last['message'].values.last
end

def get_email(record)
  message(record)['email'].values.last
rescue StandardError
  nil
end

def message(record)
  JSON.parse(record.dig('Sns', 'Message'))['data']
end

def send_email(destination_email:, body:, subject:, ses_client:)
  ses_client.send_email(
    destination: {
      to_addresses: [
        destination_email
      ]
    },
    message: {
      body: {
        text: {
          charset: 'UTF-8',
          data: body
        }
      },
      subject: {
        charset: 'UTF-8',
        data: subject
      }
    },
    source: '[email protected]'
  )
end