#
# Author:: John Keiser (<jkeiser@opscode.com>)
# Copyright:: Copyright (c) 2012 Opscode, 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_fs/file_system/base_fs_object'
require 'digest/md5'

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

      attr_reader :file

      def checksum
        file[:checksum]
      end

      def read
        old_sign_on_redirect = rest.sign_on_redirect
        rest.sign_on_redirect = false
        begin
          tmpfile = rest.get_rest(file[:url], true)
        rescue Timeout::Error => e
          raise ChefFS::FileSystem::OperationFailedError.new(:read, self, e), "Timeout reading #{file[:url]}: #{e}"
        rescue Net::HTTPServerException => e
          raise ChefFS::FileSystem::OperationFailedError.new(:read, self, e), "#{e.message} retrieving #{file[:url]}"
        ensure
          rest.sign_on_redirect = old_sign_on_redirect
        end

        begin
          tmpfile.open
          tmpfile.read
        ensure
          tmpfile.close!
        end
      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 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)
        Digest::MD5.hexdigest(value)
      end
    end
  end
end