module Uricp::Strategy
  module Common
    include Methadone::CLILogging
    include Uricp::CurlPrimitives

    def initialize(options)
      @options = options
      debug "#{self.class.name}: options are #{options.inspect}"
    end

    attr_reader :proposed_options

    def unsupported_transfer
      raise Uricp::UnsupportedURLtype,
            "Unsupported transfer from #{from} to #{to}"
    end

    alias command unsupported_transfer

    def all_local_files?
      !sequence_complete? && file_source? && to.scheme == 'file'
    end

    def compression_required?
      options['compress']
    end

    def segmented?
      options['segment-size']
    end

    def conversion_required?
      options['target-format']
    end

    def always_write_sparse?
      options['force']
    end

    def lz4?(magic)
      magic.unpack('V') == [0x184D2204]
    end

    def qcow2?(magic)
      magic.unpack('a3C') == ['QFI', 0xfb]
    end

    def encoding(io)
      magic = io.read(4).to_s
      if lz4?(magic)
        :lz4
      elsif qcow2?(magic)
        version = io.read(4)
        case version.unpack('N')
        when [2]
          :qcow2
        when [3]
          :qcow3
        else
          :qcow2un
        end
      else
        :raw
      end
    end

    def format_change?
      conversion_required? && (
        options['source-format'] != options['target-format']
      )
    end

    def dry_run?
      options['dry-run']
    end

    def lz4_source?
      options['source-format'] == :lz4
    end

    def raw_target?
      options['target-format'] == :raw
    end

    def file_source?
      from.scheme == 'file'
    end

    def sequence_complete?
      from == to
    end

    PIPE_URI = URI('pipe:/')

    def get_temp_filename(base_dir)
      t = Time.now.strftime('%Y%m%d')
      File.join(base_dir, "uricp-#{t}-#{$$}-#{rand(0x100000000).to_s(36)}")
    end

    def proposed_path
      proposed_options['from_uri'].path
    end

    def temp_uri
      URI.join('file:///', get_temp_filename(options['temp']))
    end

    def supported_source?
      options['source-format'] && !lz4_source?
    end

    def rbd_target(uri)
      uri.path[1..-1]
    end

    def rbd_id
      'libvirt'
    end
  end
end