require 'open4'

class SourceTreeSyncer
  RSYNC_TRANSPORT_SSH = 'ssh'
  RSYNC_TRANSPORT_ANONYMOUS = 'anonymous'

  attr_reader :sys_command, :output, :errors

  SYS_COMMAND = 'rsync'
  OPTS = '-azr --timeout=5 --delete'
  RSH_OPTS = 'ssh -o NumberOfPasswordPrompts=0 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i gorgon.pem'
  EXCLUDE_OPT = '--exclude'

  def initialize(sync_config)
    if sync_config
      @source_tree_path = sync_config[:source_tree_path]
      @exclude = sync_config[:exclude]
      @rsync_transport = sync_config[:rsync_transport]
    end
  end

  # TODO: rename sync to pull
  def sync
    return if blank_source_tree_path?

    @tempdir = Dir.mktmpdir("gorgon")
    Dir.chdir(@tempdir)

    @sys_command = "#{SYS_COMMAND} #{rsync_options} #{@source_tree_path}/ ."

    execute_command
  end

  def push
    return if blank_source_tree_path?

    @sys_command = "#{SYS_COMMAND} #{rsync_options} . #{@source_tree_path}"

    execute_command
  end

  def success?
    @exitstatus == 0
  end

  def remove_temp_dir
    FileUtils::remove_entry_secure(@tempdir) if @tempdir
  end

  private

  def execute_command
    pid, stdin, stdout, stderr = Open4::popen4 @sys_command
    stdin.close

    ignore, status = Process.waitpid2 pid

    @output, @errors = [stdout, stderr].map { |p| begin p.read ensure p.close end }

    @exitstatus = status.exitstatus
  end

  def blank_source_tree_path?
    if @source_tree_path.nil?
      @errors = "Source tree path cannot be nil. Check your gorgon.json file."
    elsif @source_tree_path.strip.empty?
      @errors = "Source tree path cannot be empty. Check your gorgon.json file."
    end

    if @errors
      @exitstatus = 1
      return true
    else
      return false
    end
  end

  def rsync_options
    if @rsync_transport == RSYNC_TRANSPORT_SSH
      "#{OPTS} #{exclude_options} --rsh='#{RSH_OPTS}'"
    else
      "#{OPTS} #{exclude_options}"
    end
  end

  def exclude_options
    return "" if @exclude.nil? or @exclude.empty?

    exclude = [""] + @exclude
    exclude.join(" #{EXCLUDE_OPT} ")
  end
end