gopro.rb

class GoproClient
  attr_reader :ip_address
  attr_reader :password
  attr_reader :delay

  def initialize(ip_address, password, delay = 1.0)
    @ip_address = ip_address
    @password   = password
    @delay      = delay
  end

  def power_on
    bacpac('PW', 1)
  end

  def power_off
    bacpac('PW', 0)
  end

  def mode_photo
    camera('CM', 1)
  end

  def photo_resolution(preset)
    camera('PR', preset)
  end

  def start_capture
    bacpac('SH', 1)
  end

  def stop_capture
    bacpac('SH', 0)
  end

  def capture_photo
    start_capture
    last_dir  = directories.last
    last_file = files(last_dir[:href]).last

    last_file[:url]
  end

  def directories
    html = Nokogiri::HTML(open(storage_url))
    html.search('a.link').map do |a|
      {name: a.text, href: a[:href], url: storage_url(a[:href])}
    end
  end

  def files(dir)
    html = Nokogiri::HTML(open(storage_url(dir)))
    html.search('a.link').map do |a|
      {name: a.text, href: a[:href], url: storage_url(dir + '/' + a[:href]), }
    end
  end

  private

  def bacpac(method, param)
    output = open(api_url('bacpac', method, param)).read
    sleep delay
    output
  end

  def camera(method, param)
    output = open(api_url('camera', method, param)).read
    sleep delay
    output
  end

  def api_url(component, method, param)
    url = sprintf('http://%s/%s/%s?t=%s&p=%%%02d', ip_address, component, method, password, param)
    puts url
    url
  end

  def storage_url(path = '')
    url = sprintf('http://%s:8080/videos/DCIM/%s', ip_address, path)
    puts url
    url
  end
end