module Messaging
  module Adapters
    class Postgres
      class Stream
        # @return [String] the name of the stream
        attr_reader :name

        # @return [String] the stream category
        attr_reader :category

        # @return [String] the stream id
        attr_reader :id

        # Should not be used directly.
        # Use {Messaging.stream} or {Store#stream}
        # @api private
        # @see Messaging.stream
        # @see Store.stream
        def initialize(name)
          @name = name
          @category, @id = name.split('$')
        end

        # Access to all messages in the stream sorted by stream_position
        # @return [ActiveRecord::Relation]
        def messages
          SerializedMessage.where(stream_category: category, stream_id: id).order(:stream_position)
        end

        # The current position of the last message in the stream
        # @return [-1] if the stream is empty -1 will be returned
        # @return [Integer] the stream position of the last message in the stream
        def current_position
          messages.maximum(:stream_position) || -1
        end

        def to_s
          name
        end

        def inspect
          info = "current_position: #{current_position}"
          "#<Stream:#{name}> #{info}>"
        end
      end
    end
  end
end