module Guard::Notifier

def _auto_detect_notification
  self.notifiers = []
  available = nil
  NOTIFIERS.each do |group|
    notifier_added = group.find { |name, klass| add_notifier(name, silent: true) }
    available ||= notifier_added
  end
  ::Guard::UI.info('Guard could not detect any of the supported notification libraries.') unless available
end

def _get_notifier_module(name)
  NOTIFIERS.each do |group|
    if notifier = group.find { |n, _| n == name }
      return notifier.last
    end
  end
  nil
end

def add_notifier(name, opts = {})
  return turn_off if name == :off
  notifier_class = _get_notifier_module(name)
  if notifier_class && notifier_class.available?(opts)
    self.notifiers = notifiers << { name: name, options: opts }
    true
  else
    false
  end
end

def clear_notifiers
  ENV['GUARD_NOTIFIERS'] = nil
end

def enabled?
  ENV['GUARD_NOTIFY'] == 'true'
end

def notifiers
  ENV['GUARD_NOTIFIERS'] ? YAML::load(ENV['GUARD_NOTIFIERS']) : []
end

def notifiers=(notifiers)
  ENV['GUARD_NOTIFIERS'] = YAML::dump(notifiers)
end

def notify(message, opts = {})
  return unless enabled?
  notifiers.each do |notifier|
    notifier = _get_notifier_module(notifier[:name]).new(notifier[:options])
    begin
      notifier.notify(message, opts)
    rescue Exception => e
      ::Guard::UI.error "Error sending notification with #{ notifier.name }: #{ e.message }"
    end
  end
end

def toggle
  if enabled?
    ::Guard::UI.info 'Turn off notifications'
    turn_off
  else
    turn_on
  end
end

def turn_off
  notifiers.each do |notifier|
    notifier_class = _get_notifier_module(notifier[:name])
    notifier_class.turn_off if notifier_class.respond_to?(:turn_off)
  end
  ENV['GUARD_NOTIFY'] = 'false'
end

def turn_on
  _auto_detect_notification if notifiers.empty? && (!::Guard.options || ::Guard.options[:notify])
  if notifiers.empty?
    turn_off
  else
    notifiers.each do |notifier|
      notifier_class = _get_notifier_module(notifier[:name])
      ::Guard::UI.info "Guard is using #{ notifier_class.title } to send notifications."
      notifier_class.turn_on if notifier_class.respond_to?(:turn_on)
    end
    ENV['GUARD_NOTIFY'] = 'true'
  end
end