require 'uri'
require 'net/http'
require 'openssl'

DEFAULT_USERAGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36'
DEFAULT_SSL_NO_VERIFY = false

class ResponseCheck

  ## Class Methods with class variables.
  def self.useragent=(useragent)
    case useragent
      when nil
        @@useragent = DEFAULT_USERAGENT
      else
        @@useragent = useragent
    end
  end
  def self.useragent
    @@useragent
  end

  # a class accessor
  def self.ssl_no_verify=(verify)
    @@ssl_no_verify = verify
  end
  def self.ssl_no_verify
    @@ssl_no_verify
  end


  ## Instance Methods following:
  attr_reader :get_uri, :parsed_uri
  attr_accessor :ssl_no_verify, :useragent, :wanted_dst_uri

  def initialize(options)
    # required at init
    @get_uri        = options[:get_uri] || abort("#{self.class.name}: no get_uri given")

    # optional at init. can be set by accessor.
    @wanted_dst_uri = options[:wanted_dst_uri] ||= nil
    @ssl_no_verify  = options[:ssl_no_verify]  ||= @@ssl_no_verify ||= DEFAULT_SSL_NO_VERIFY
    @useragent      = options[:useragent]      ||= @@useragent     ||= DEFAULT_USERAGENT

    # those are just reader
    @parsed_uri  ||= uri(@get_uri)
  end

  ### response code mappings following here.
  ### also see: https://en.wikipedia.org/wiki/URL_redirection

  def http2xx?
    response.is_a?(Net::HTTPSuccess) # any http 2xx code
  end
  def success?
    http2xx?
  end

  def http200?
    response.is_a?(Net::HTTPOK)
  end
  def ok?
    http200?
  end

  def http3xx?
    response.is_a?(Net::HTTPRedirection) # any http 3xx code
  end
  def redirect? # an alias for 'http3xx?'
    http3xx?
  end

  def http301?
    http3xx? && response.is_a?(Net::HTTPMovedPermanently) # 301
  end
  def permanent_redirect? # an alias for 'http301?'
    http301?
  end

  def http302?
    http3xx? && response.is_a?(Net::HTTPFound) # 302
  end

  def http303?
    http3xx? && response.is_a?(Net::HTTPMovedTemporarily) # 303
  end
  def see_other_temp_redirect? # an alias for 'http303?'
    http303?
  end

  def http304?
    http3xx? && response.is_a?(Net::HTTPNotModified) # 304
  end

  def http305?
    http3xx? && response.is_a?(Net::HTTPUseProxy) # 305
  end

  def http307?
    http3xx? && response.is_a?(Net::HTTPTemporaryRedirect) # 307
  end
  def strict_temp_redirect? # an alias for 'http307?'
    http307?
  end

  def body
    response.body
  end

  def body_contains?(contains)
    begin
      if body.to_s.match(contains)
        true
      else
        false
      end
    rescue
      false
    end
  end

  def redirected_path
    response['location'].sub(/#{Regexp.escape("#{uri.scheme}://#{uri.host}")}/, '') if redirect?
  end

  def redirected_uri
    response['location'] if redirect?
  end

  def response
    if @useragent.to_s.size < 5
      abort "#{self.class.name}: useragent '" + @useragent + "' is very short. Thus, just wrong."
    #else
    #  puts "Using UA: " + @useragent
    end

    @verify_mode ||= OpenSSL::SSL::VERIFY_NONE if @ssl_no_verify

    @response ||= Net::HTTP.start(@parsed_uri.host,
                                  @parsed_uri.port,
                                  :use_ssl     => @parsed_uri.scheme == 'https',
                                  :verify_mode => @verify_mode
    ) {|http|
      http.request(Net::HTTP::Get.new(@parsed_uri.path, {'User-Agent' => @useragent}) )
    }
    return @response
  end

  private

  def uri(uri)
    check_uri = URI.parse(uri.to_s)
    if not check_uri.path.to_s.size > 0
      check_uri.path = '/'
    end
    if not check_uri.scheme =~ /http[s]?/
      abort "Must be either http or https"
    end
    URI.parse(check_uri.to_s)
  end

end