require 'yaml'

module Bib
  module Vagrant
    class Config
      @@home_dir = nil
      @@verbose = true

      def initialize(home = '~', verbose = true)
        @@home = home
        @@verbose = verbose
      end

      def get
        vagrantconfig = get_defaults

        begin
          localconfigfile = File.open(get_path, 'r')
          vagrantconfig.merge!(YAML.load(localconfigfile.read))
        rescue Errno::ENOENT
          puts 'WARNING: No vagrant user-config found, using default cookbook path' if @@verbose
          create(get_path, vagrantconfig)
        end

        vagrantconfig
      end

      def has?
        File.exist?(get_path)
      end

      def get_path
        File.expand_path("#{@@home}/.config/easybib/vagrantdefault.yml")
      end

      def validate!(config)
        current_config_keys = config.keys

        get_defaults.keys.each do |required_key|
          fail "Missing #{required_key}!" unless current_config_keys.include?(required_key)
        end

        errors = []
        log_level = %w(debug info warn error fatal)
        bool = [TrueClass, FalseClass]

        cookbook_path = File.expand_path(config['cookbook_path'])

        errors << 'nfs: must be a boolean' unless bool.include?(config['nfs'].class)
        errors << 'gui: must be a boolean' unless bool.include?(config['gui'].class)
        errors << 'cookbook_path: does not exist' unless File.directory?(cookbook_path)
        errors << "chef_log_level: must be one of #{log_level.join}" unless log_level.include?(config['chef_log_level'])

        unless config['additional_json'].empty?
          errors << 'additional_json: must be empty or valid json' unless is_valid_json?(config['additional_json'])
        end

        return true if errors.count == 0

        fail "Errors: #{errors.join(', ')}"
      end

      private

      def create(localconfigpath, vagrantconfig)
        FileUtils.mkdir_p(File.dirname(localconfigpath))
        File.open(localconfigpath, 'w+') do |file|
          file.write(vagrantconfig.to_yaml)
          puts "INFO: Created default vagrant user-config in #{localconfigpath}" if @@verbose
          puts 'INFO: You probably want to fix the path to the cookbooks in this file.' if @@verbose
        end
      rescue
        puts "WARNING: Unable to create default #{localconfigpath} - please do it manually." if @@verbose
      end

      def get_defaults
        {
          'nfs' => false,
          'cookbook_path' => '~/Sites/easybib/cookbooks',
          'chef_log_level' => 'debug',
          'additional_json' => '{}',
          'gui' => false
        }
      end

      def is_valid_json?(json)
        JSON.parse(json)
        return true
      rescue JSON::ParserError
        false
      end
    end
  end
end