require "net/scp"

module Backup
  module Storage
    class SCP < Base
      include Storage::Cycler
      class Error < Backup::Error; end

      ##
      # Server credentials
      attr_accessor :username, :password, :ssh_options

      ##
      # Server IP Address and SCP port
      attr_accessor :ip, :port

      def initialize(model, storage_id = nil)
        super

        @port ||= 22
        @path ||= "backups"
        @ssh_options ||= {}
        path.sub!(/^~\//, "")
      end

      private

      def connection
        Net::SSH.start(
          ip, username, { password: password, port: port }.merge(ssh_options)
        ) { |ssh| yield ssh }
      end

      def transfer!
        connection do |ssh|
          ssh.exec!("mkdir -p '#{remote_path}'")

          package.filenames.each do |filename|
            src = File.join(Config.tmp_path, filename)
            dest = File.join(remote_path, filename)
            Logger.info "Storing '#{ip}:#{dest}'..."
            ssh.scp.upload!(src, dest)
          end
        end
      end

      # Called by the Cycler.
      # Any error raised will be logged as a warning.
      def remove!(package)
        Logger.info "Removing backup package dated #{package.time}..."

        errors = []
        connection do |ssh|
          ssh.exec!("rm -r '#{remote_path_for(package)}'") do |_, stream, data|
            errors << data if stream == :stderr
          end
        end
        unless errors.empty?
          raise Error, "Net::SSH reported the following errors:\n" +
            errors.join("\n")
        end
      end
    end
  end
end
