class Fauxhai::Fetcher

def cache
  @cache ||= JSON.parse(File.read(cache_file))
end

def cache_file
  File.expand_path(File.join(Fauxhai.root, "tmp", cache_key))
end

def cache_key
  Digest::SHA2.hexdigest("#{user}@#{host}")
end

def cached?
  File.exist?(cache_file)
end

def force_cache_miss?
  @force_cache_miss ||= @options.delete(:force_cache_miss) || false
end

def host
  @host ||= begin
    raise ArgumentError, ":host is a required option for Fauxhai.fetch" unless @options[:host]
    @options.delete(:host)
  end
end

def initialize(options = {}, &override_attributes)
  @options = options
  if !force_cache_miss? && cached?
    @data = cache
  else
    require "net/ssh" unless defined?(Net::SSH)
    Net::SSH.start(host, user, @options) do |ssh|
      @data = JSON.parse(ssh.exec!("ohai"))
    end
    # cache this data so we do not have to SSH again
    File.open(cache_file, "w+") { |f| f.write(@data.to_json) }
  end
  yield(@data) if block_given?
  if defined?(ChefSpec)
    data = @data
    ::ChefSpec::Runner.send :define_method, :fake_ohai do |ohai|
      data.each_pair do |attribute, value|
        ohai[attribute] = value
      end
    end
  end
  @data
end

def to_hash(*args)
  @data.to_hash(*args)
end

def to_s
  "#<Fauxhai::Fetcher @host=#{host}, @options=#{@options}>"
end

def user
  @user ||= (@options.delete(:user) || ENV["USER"] || ENV["USERNAME"]).chomp
end