module NoMoreCaptcha
  require 'base64'
  require 'uri'
  require 'httparty'

  # Disable SSL verification
  HTTParty::Basement.default_options.update(verify: false)

  class Captcha
    attr_accessor :service, :api_key
    attr_reader :balance

    AntiCaptchaService  = 'http://anti-captcha.com'
    AntiGateService     = 'http://antigate.com'
    RIPCaptchaService   = 'http://ripcaptcha.com/'
    RUCaptchaService    = 'https://rucaptcha.com'

    def initialize service, api_key
      @service = service
      @api_key = api_key
      @balance = 0
      update_balance()
    end

    # Updates @balance
    def update_balance
      response = HTTParty.get build_url "#{@service}/res.php", {:action => 'getbalance', :key => @api_key}

      unless response.code == 200
        puts "HTTP error: #{response.code}"
        return false
      end

      case response.body
      when "ERROR_WRONG_USER_KEY", "ERROR_KEY_DOES_NOT_EXIST"
        abort "Wrong API key"
      else
        @balance = response.body
      end
    end

    # Returns text from passed image URL
    def recognize image_url, parameters = nil
      if parameters
        raise ArgumentError, "parameters should be hash" unless parameters.kind_of?(Hash)
      end

      return false unless image = get_image(image_url)

      return false unless captcha_id = upload_image(image, parameters)

      return false unless captcha_text = check_captcha(captcha_id)

      captcha_text
    end

    private

    def build_url url, parameters
      raise ArgumentError, "parameters should be hash" unless parameters.kind_of?(Hash)

      parameters.each_with_index do |(parameter, value), index|
        prefix = index == 0 ? '?' : '&'
        url += "#{prefix}#{parameter}=#{URI.encode(value.to_s)}"
      end

      url
    end

    # Returns base64 encrypted image
    def get_image image_url
      begin
        response = HTTParty.get image_url
      rescue
        puts "Can't get an image from URL: \"#{image_url}\""
        return false
      end

      Base64.encode64 response.body
    end

    # Uploads an image to captcha recognition service
    def upload_image image_base64, parameters = nil
      if parameters
        raise ArgumentError, "parameters should be hash" unless parameters.kind_of?(Hash)
      end

      begin
        body = {:method => 'base64', :key => @api_key, :body => image_base64}

        if parameters
          body.merge!(parameters)
        end

        response = HTTParty.post "#{@service}/in.php", :body => body
      rescue
        puts "Can't upload image"
        return false
      end

      return false unless response = handle_response(response.body)

      response
    end

    # Check if captcha is ready
    def check_captcha captcha_id
      5.times do
        sleep 5

        response = HTTParty.get build_url "#{@service}/res.php", {:action => 'get', :id => captcha_id, :key => @api_key}

        return false unless captcha_text = handle_response(response.body)

        if captcha_text != true
          return captcha_text
        end
      end

      false
    end

    def handle_response response
      case response
      when "ERROR_WRONG_USER_KEY"
        puts "Wrong API key format"
        return false

      when "ERROR_KEY_DOES_NOT_EXIST"
        puts "API key does not exist"
        return false

      when "ERROR_ZERO_BALANCE"
        puts "Zero balance"
        return false

      when "ERROR_NO_SLOT_AVAILABLE"
        puts "No available slots"
        return false

      when "ERROR_ZERO_CAPTCHA_FILESIZE"
        puts "Your captcha size is less than 100kb"
        return false

      when "ERROR_WRONG_FILE_EXTENSION"
        puts "Wrong captcha file extension"
        return false

      when "ERROR_IMAGE_TYPE_NOT_SUPPORTED"
        puts "Captcha image type not supported"
        return false

      when "ERROR_IP_NOT_ALLOWED"
        pust "Requests from your IP are not allowed"
        return false

      when "CAPCHA_NOT_READY"
        puts "Captcha is not ready"
        return true

      when "ERROR_WRONG_ID_FORMAT"
        puts "Wrong captcha ID format"
        return false

      when "ERROR_CAPTCHA_UNSOLVABLE"
        puts "Captcha is unsolvable"
        return false
      end

      if response.start_with? 'OK|'
        return response[3..-1]
      end

      false
    end

  end
end

include NoMoreCaptcha

captcha = Captcha.new Captcha::RUCaptchaService, '5034b431e072a5472d5b33d88bacaa65'

puts "#{captcha.balance} rubles"

# http://i.imgur.com/Ni4NYbo.png
text = captcha.recognize 'http://somepony.org/getacutiemark/captcha.php'

if text
  puts "Our captcha is #{text}"
end