#
# Author:: John Keiser (<jkeiser@chef.io>)
# Copyright:: Copyright 2012-2016, Chef Software Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require "chef/chef_fs/file_system/base_fs_object"
require "chef/http/simple"
require "openssl"

class Chef
  module ChefFS
    module FileSystem
      module ChefServer
        class CookbookFile < BaseFSObject
          def initialize(name, parent, file)
            super(name, parent)
            @file = file
          end

          attr_reader :file

          def checksum
            file[:checksum]
          end

          def read
            tmpfile = rest.streaming_request(file[:url])
            File.open(tmpfile, "rb") { |f| f.read }
          rescue Timeout::Error => e
            raise Chef::ChefFS::FileSystem::OperationFailedError.new(:read, self, e, "Timeout reading #{file[:url]}: #{e}")
          rescue Net::HTTPClientException => e
            raise Chef::ChefFS::FileSystem::OperationFailedError.new(:read, self, e, "#{e.message} retrieving #{file[:url]}")
          rescue Errno::ENOENT
            raise Chef::ChefFS::FileSystem::NotFoundError.new(self, $!)
          end

          def rest
            parent.rest
          end

          def compare_to(other)
            other_value = nil
            if other.respond_to?(:checksum)
              other_checksum = other.checksum
            else
              begin
                other_value = other.read
              rescue Chef::ChefFS::FileSystem::NotFoundError
                return [ false, nil, :none ]
              end
              other_checksum = calc_checksum(other_value)
            end
            [ checksum == other_checksum, nil, other_value ]
          end

          private

          def calc_checksum(value)
            OpenSSL::Digest::MD5.hexdigest(value)
          end
        end
      end
    end
  end
end