module Spring

def self.command(name)
  commands.fetch name
end

def self.command?(name)
  commands.include? name
end

def self.register_command(name, command = nil)
  commands[name] = CommandWrapper.new(name, command)
end

def self.watch(*items)
  watcher.add *items
end

def self.watch_method=(method)
  case method
  when :polling
    require_relative "watcher/polling"
    @watch_method = Watcher::Polling
  when :listen
    require_relative "watcher/listen"
    @watch_method = Watcher::Listen
  else
    @watch_method = method
  end
end

def self.watcher
  @watcher ||= watch_method.new(Spring.application_root_path, watch_interval)
end

def after_fork(&block)
  after_fork_callbacks << block
end

def after_fork_callbacks
  @after_fork_callbacks ||= []
end

def application_root_path
  @application_root_path ||= begin
    if application_root
      path = Pathname.new(File.expand_path(application_root))
    else
      path = project_root_path
    end
    raise MissingApplication.new(path) unless path.join("config/application.rb").exist?
    path
  end
end

def find_project_root(current_dir)
  if current_dir.join(gemfile).exist?
    current_dir
  elsif current_dir.root?
    raise UnknownProject.new(Dir.pwd)
  else
    find_project_root(current_dir.parent)
  end
end

def gemfile
  ENV['BUNDLE_GEMFILE'] || "Gemfile"
end

def project_root_path
  @project_root_path ||= find_project_root(Pathname.new(File.expand_path(Dir.pwd)))
end

def verify_environment
  application_root_path
end