module ActiveAdmin::DependencyChecker

def check!
  if rails_3_1?
    unless meta_search_1_1? && sass_rails_3_1?
      warn "ActiveAdmin requires meta_search >= 1.1.0.pre and sass-rails ~> 3.1.0.rc to work with rails >= 3.1.0"
    end
  end
  if pry_rails_before_0_1_6?
    warn "ActiveAdmin is not compatible with pry-rails < 0.1.6. Please upgrade pry-rails."
  end
end

def meta_search_1_1?
  Gem.loaded_specs['meta_search'].version.to_s >= "1.1"
end

def pry_rails_before_0_1_6?
  begin
    PryRails::VERSION < "0.1.6"
  rescue NameError
    false
  end
end

def rails_3_1?
  Rails::VERSION::MAJOR == 3 && Rails::VERSION::MINOR >= 1
end

def sass_rails_3_1?
  require 'sass/rails/version'
  Sass::Rails::VERSION >= "3.1"
rescue LoadError
  false
end