#
# Copyright (c) 2013, Seth Chisamore
#
# 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 "rubygems/dependency"
require "rubygems/dependency_installer"
require "vagrant"
require "vagrant/errors"
require "vagrant/util/template_renderer"

module VagrantPlugins
  #
  module Omnibus
    # @author Seth Chisamore <schisamo@chef.io>
    class Config < Vagrant.plugin("2", :config)
      # @return [String]
      #   The version of Chef to install.
      attr_accessor :chef_version, :install_url, :cache_packages

      def initialize
        @chef_version = UNSET_VALUE
        @install_url = UNSET_VALUE
        @cache_packages = UNSET_VALUE
        @logger = Log4r::Logger.new("vagrantplugins::omnibus::config")
      end

      def finalize!
        if @chef_version == UNSET_VALUE
          @chef_version = nil
        end
        # enable caching by default
        @cache_packages = true if @cache_packages == UNSET_VALUE
        # nil means default install.sh|msi
        @install_url = nil if @install_url == UNSET_VALUE
      end

      #
      # Performs validation and immediately raises an exception for any
      # detected errors.
      #
      # @raise [Vagrant::Errors::ConfigInvalid]
      #   if validation fails
      #
      def validate!(machine)
        finalize!
        errors = []

        if !chef_version.nil? && !valid_chef_version?(chef_version)
          msg = <<-EOH
'#{ chef_version }' is not a valid version of Chef.

A list of valid versions can be found at: https://downloads.chef.io/chef-client/
          EOH
          errors << msg
        end

        if errors.any?
          rendered_errors = Vagrant::Util::TemplateRenderer.render(
                              "config/validation_failed",
                              errors: { "vagrant-omnibus" => errors }
                            )
          raise Vagrant::Errors::ConfigInvalid, errors: rendered_errors
        end
      end

      private

      # Query RubyGems.org's Ruby API to see if the user-provided Chef version
      # is in fact a real Chef version!
      def valid_chef_version?(version)
        return true if version.to_s == "latest"
        begin
          available = dependency_installer.find_gems_with_sources(
            chef_gem_dependency(version)
          )
        rescue ArgumentError => e
          @logger.debug("#{version} is not a valid Chef version: #{e}")
          return false
        end
        return !available.empty?
      end

      def dependency_installer
        @dependency_installer ||= Gem::DependencyInstaller.new
      end

      def chef_gem_dependency(version = nil)
        Gem::Dependency.new("chef", version)
      end
    end
  end
end