require 'open-uri'
module Uricp::Strategy
  class PipedRemoteGet
    include Uricp::Strategy::Common

    def appropriate?
      case from.scheme
      when 'http', 'https'
        return proposal unless sequence_complete?
      else
        debug "#{self.class.name}: not appropriate"
        false
      end
    end

    alias command curl_download_to_pipe

    def proposal
      @proposed_options = options.dup
      @proposed_options['from_uri'] = PIPE_URI
      if conversion_required?
        @proposed_options['source-format'] = format_peek
        if @proposed_options['source-format'] == @proposed_options['target-format']
          @proposed_options.delete('source-format')
          @proposed_options.delete('target-format')
        end
      end
      if options['max-cache'] &&
         size_peek.to_i > options['max-cache'].to_i
        @proposed_options.delete('cache')
        @proposed_options.delete('cache_name')
        @proposed_options.delete('max-cache')
      end
      self
    end

    def format_peek
      return options['target-format'] || 'raw' if dry_run?

      options['from_uri'].open(headers) do |u|
        encoding(u)
      end
    rescue OpenURI::HTTPError => e
      case e.io.status[0]
      when '416'
        'raw'
      else
        raise
      end
    rescue SocketError => e
      raise SocketError, options['from_uri'].to_s + ' inaccessible: ' + e.message
    end

    def size_peek
      return options['max-cache'] if dry_run?

      size_headers = headers
      size_headers['Range'] = 'bytes=0-0'
      options['from_uri'].open(headers) do |u|
        match = %r{bytes\s+(\d+)-(\d+)/(\d+|\*)}i.match(u.meta['content-range'])
        match && match[3].to_i
      end
    rescue OpenURI::HTTPError => e
      case e.io.status[0]
      when '416'
        0
      else
        raise
      end
    rescue SocketError => e
      raise SocketError, options['from_uri'].to_s + ' inaccessible: ' + e.message
    end

    def headers
      headers = { 'Range' => 'bytes=0-7' }
      headers['X-Auth-Token'] = options['authenticator'].call if http_authentication?
      headers
    end
  end
end