class Guard::Dsl

def callback(*args, &listener)
  listener, events = args.size > 1 ? args : [listener, args[0]]
  @callbacks << { :events => events, :listener => listener }
end

def evaluate_guardfile(options = {})
  raise ArgumentError.new('No option hash passed to evaluate_guardfile!') unless options.is_a?(Hash)
  @@options = options.dup
  fetch_guardfile_contents
  instance_eval_guardfile(guardfile_contents_with_user_config)
end

def fetch_guardfile_contents
  if @@options[:guardfile_contents]
    UI.info 'Using inline Guardfile.'
    @@options[:guardfile_path] = 'Inline Guardfile'
  elsif @@options[:guardfile]
    if File.exist?(@@options[:guardfile])
      read_guardfile(@@options[:guardfile])
      UI.info "Using Guardfile at #{ @@options[:guardfile] }."
    else
      UI.error "No Guardfile exists at #{ @@options[:guardfile] }."
      exit 1
    end
  else
    if File.exist?(guardfile_default_path)
      read_guardfile(guardfile_default_path)
    else
      UI.error 'No Guardfile found, please create one with `guard init`.'
      exit 1
    end
  end
  unless guardfile_contents_usable?
    UI.error "The command file(#{ @@options[:guardfile] }) seems to be empty."
    exit 1
  end
end

def group(name, options = {})
  @groups = @@options[:group] || []
  name    = name.to_sym
  if block_given? && (@groups.empty? || @groups.map(&:to_sym).include?(name))
    ::Guard.add_group(name.to_s.downcase, options)
    @current_group = name
    yield if block_given?
    @current_group = nil
  end
end

def guard(name, options = {})
  @watchers  = []
  @callbacks = []
  @current_group ||= :default
  yield if block_given?
  options.update(:group => @current_group)
  ::Guard.add_guard(name.to_s.downcase, @watchers, @callbacks, options)
end

def guardfile_contents
  @@options ? @@options[:guardfile_contents] : ''
end

def guardfile_contents_usable?
  guardfile_contents && guardfile_contents.size >= 'guard :a'.size # Smallest Guard definition
end

def guardfile_contents_with_user_config
  config = File.read(user_config_path) if File.exist?(user_config_path)
  [guardfile_contents, config].join("\n")
end

def guardfile_default_path
  File.exist?(local_guardfile_path) ? local_guardfile_path : home_guardfile_path
end

def guardfile_include?(guard_name)
  guardfile_contents.match(/^guard\s*\(?\s*['":]#{ guard_name }['"]?/)
end

def guardfile_path
  @@options ? @@options[:guardfile_path] : ''
end

def home_guardfile_path
  File.expand_path(File.join('~', '.Guardfile'))
end

def ignore_paths(*paths)
  UI.info "Ignoring paths: #{ paths.join(', ') }"
  ::Guard.listener.ignore_paths.push(*paths)
end

def instance_eval_guardfile(contents)
  new.instance_eval(contents, @@options[:guardfile_path], 1)
rescue
  UI.error "Invalid Guardfile, original error is:\n#{ $! }"
  exit 1
end

def interactor(interactor)
  ::Guard::Interactor.interactor = interactor.to_sym
end

def local_guardfile_path
  File.join(Dir.pwd, 'Guardfile')
end

def notification(notifier, options = {})
  ::Guard::Notifier.add_notification(notifier.to_sym, options, false)
end

def read_guardfile(guardfile_path)
  @@options[:guardfile_path]     = guardfile_path
  @@options[:guardfile_contents] = File.read(guardfile_path)
rescue
  UI.error("Error reading file #{ guardfile_path }")
  exit 1
end

def reevaluate_guardfile
  ::Guard.run do
    # Stop each old guards
    ::Guard.run_on_guards do |guard|
      ::Guard.run_supervised_task(guard, :stop)
    end
    ::Guard.guards.clear
    ::Guard.reset_groups
    ::Guard::Notifier.clear_notifications
    @@options.delete(:guardfile_contents)
    Dsl.evaluate_guardfile(@@options)
    UI.error 'No guards found in Guardfile, please add at least one.' if ::Guard.guards.empty?
    msg = 'Guardfile has been re-evaluated.'
    UI.info(msg)
    Notifier.notify(msg)
    # Start each new guards
    ::Guard.run_on_guards do |guard|
      ::Guard.run_supervised_task(guard, :start)
    end
  end
end

def user_config_path
  File.expand_path(File.join('~', '.guard.rb'))
end

def watch(pattern, &action)
  @watchers << ::Guard::Watcher.new(pattern, action)
end