module Tapioca::GemHelper

def gem_in_app_dir?(app_dir, full_gem_path)
  app_dir = to_realpath(app_dir)
  full_gem_path = to_realpath(full_gem_path)
  !gem_in_bundle_path?(full_gem_path) && !gem_in_ruby_path?(full_gem_path) && path_in_dir?(full_gem_path, app_dir)
end

def gem_in_bundle_path?(full_gem_path)
  path_in_dir?(full_gem_path, Bundler.bundle_path) || path_in_dir?(full_gem_path, Bundler.app_cache)
end

def gem_in_ruby_path?(full_gem_path)
  path_in_dir?(full_gem_path, RbConfig::CONFIG["rubylibprefix"])
end

def path_in_dir?(path, dir)
  dir = Pathname.new(dir)
  path = Pathname.new(path)
  path.ascend.any?(dir)
end

def to_realpath(path)
  path_string = path.to_s
  path_string = File.realpath(path_string) if File.exist?(path_string)
  path_string
end