# -*- encoding: utf-8 -*-
#
# Author:: Fletcher Nichol (<fnichol@nichol.ca>)
#
# Copyright (C) 2013, Fletcher Nichol
#
# 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 'kitchen/errors'
require 'kitchen/logging'

module Kitchen

  module Provisioner

    module Chef

      # Chef cookbook resolver that uses Berkshelf and a Berksfile to calculate
      # dependencies.
      #
      # @author Fletcher Nichol <fnichol@nichol.ca>
      class Berkshelf

        include Logging

        def initialize(berksfile, path, logger = Kitchen.logger)
          @berksfile  = berksfile
          @path       = path
          @logger     = logger
        end

        def resolve
          info("Resolving cookbook dependencies with Berkshelf...")
          debug("Using Berksfile from #{berksfile}")

          load_berkshelf!

          ::Berkshelf.ui.mute do
            if ::Berkshelf::Berksfile.method_defined?(:vendor)
              # Berkshelf 3.0 requires the directory to not exist
              FileUtils.rm_rf(path)
              ::Berkshelf::Berksfile.from_file(berksfile).vendor(path)
            else
              ::Berkshelf::Berksfile.from_file(berksfile).install(path: path)
            end
          end
        end

        private

        attr_reader :berksfile, :path, :logger

        def load_berkshelf!
          require 'berkshelf'
        rescue LoadError => e
          fatal("The `berkshelf' gem is missing and must be installed" +
            " or cannot be properly activated. Run" +
            " `gem install berkshelf` or add the following to your" +
            " Gemfile if you are using Bundler: `gem 'berkshelf'`.")
          raise UserError,
            "Could not load or activate Berkshelf (#{e.message})"
        end
      end
    end
  end
end