module ActiveMerchant #:nodoc:
  module Billing #:nodoc:
    class PaymillGateway < Gateway
      self.supported_countries = %w(AD AT BE BG CH CY CZ DE DK EE ES FI FO FR GB
                                    GI GR HR HU IE IL IM IS IT LI LT LU LV MC MT
                                    NL NO PL PT RO SE SI SK TR VA)

      self.supported_cardtypes = [:visa, :master, :american_express, :diners_club, :discover, :union_pay, :jcb]
      self.homepage_url = 'https://paymill.com'
      self.display_name = 'PAYMILL'
      self.money_format = :cents
      self.default_currency = 'EUR'
      self.live_url = "https://api.paymill.com/v2/"

      def initialize(options = {})
        requires!(options, :public_key, :private_key)
        super
      end

      def purchase(money, payment_method, options = {})
        action_with_token(:purchase, money, payment_method, options)
      end

      def authorize(money, payment_method, options = {})
        action_with_token(:authorize, money, payment_method, options)
      end

      def capture(money, authorization, options = {})
        post = {}

        add_amount(post, money, options)
        post[:preauthorization] = preauth(authorization)
        post[:description] = options[:order_id]
        post[:source] = 'active_merchant'
        commit(:post, 'transactions', post)
      end

      def refund(money, authorization, options={})
        post = {}

        post[:amount] = amount(money)
        post[:description] = options[:order_id]
        commit(:post, "refunds/#{transaction_id(authorization)}", post)
      end

      def void(authorization, options={})
        commit(:delete, "preauthorizations/#{preauth(authorization)}")
      end

      def store(credit_card, options={})
        save_card(credit_card)
      end

      def supports_scrubbing
        true
      end

      def scrub(transcript)
        transcript.
          gsub(%r((Authorization: Basic )\w+), '\1[FILTERED]').
          gsub(/(account.number=)(\d*)/, '\1[FILTERED]').
          gsub(/(account.verification=)(\d*)/, '\1[FILTERED]')
      end

      private

      def add_credit_card(post, credit_card)
        post['account.number'] = credit_card.number
        post['account.expiry.month'] = sprintf("%.2i", credit_card.month)
        post['account.expiry.year'] = sprintf("%.4i", credit_card.year)
        post['account.verification'] = credit_card.verification_value
      end

      def headers
        { 'Authorization' => ('Basic ' + Base64.strict_encode64("#{@options[:private_key]}:X").chomp) }
      end

      def commit(method, action, parameters=nil)
        begin
          raw_response = ssl_request(method, live_url + action, post_data(parameters), headers)
        rescue ResponseError => e
          begin
            parsed = JSON.parse(e.response.body)
          rescue JSON::ParserError
            return Response.new(false, "Unable to parse error response: '#{e.response.body}'")
          end
          return Response.new(false, response_message(parsed), parsed, {})
        end

        response_from(raw_response)
      end

      def response_from(raw_response)
        parsed = JSON.parse(raw_response)
        options = {
          :authorization => authorization_from(parsed),
          :test => (parsed['mode'] == 'test'),
        }

        succeeded = (parsed['data'] == []) || (parsed['data']['response_code'].to_i == 20000)
        Response.new(succeeded, response_message(parsed), parsed, options)
      end

      def authorization_from(parsed_response)
        parsed_data = parsed_response['data']
        return '' unless parsed_data.kind_of?(Hash)

        [
          parsed_data['id'],
          parsed_data['preauthorization'].try(:[], 'id')
        ].join(";")
      end

      def action_with_token(action, money, payment_method, options)
        case payment_method
        when String
          self.send("#{action}_with_token", money, payment_method, options)
        else
          MultiResponse.run do |r|
            r.process { save_card(payment_method) }
            r.process { self.send("#{action}_with_token", money, r.authorization, options) }
          end
        end
      end

      def purchase_with_token(money, card_token, options)
        post = {}

        add_amount(post, money, options)
        post[:token] = card_token
        post[:description] = options[:order_id]
        post[:source] = 'active_merchant'
        commit(:post, 'transactions', post)
      end

      def authorize_with_token(money, card_token, options)
        post = {}

        add_amount(post, money, options)
        post[:token] = card_token
        post[:description] = options[:order_id]
        post[:source] = 'active_merchant'
        commit(:post, 'preauthorizations', post)
      end

      def save_card(credit_card)
        post = {}

        add_credit_card(post, credit_card)
        post['channel.id'] = @options[:public_key]
        post['jsonPFunction'] = 'jsonPFunction'
        post['transaction.mode'] = (test? ? 'CONNECTOR_TEST' : 'LIVE')

        begin
          raw_response = ssl_request(:get, "#{save_card_url}?#{post_data(post)}", nil, {})
        rescue ResponseError => e
          return Response.new(false, e.response.body)
        end

        response_for_save_from(raw_response)
      end

      def response_for_save_from(raw_response)
        options = { :test => test? }

        parser = ResponseParser.new(raw_response, options)
        parser.generate_response
      end

      def parse_reponse(response)
        JSON.parse(response.sub(/jsonPFunction\(/, '').sub(/\)\z/, ''))
      end

      def save_card_url
        (test? ? 'https://test-token.paymill.com' : 'https://token-v2.paymill.de')
      end

      def post_data(params)
        return nil unless params

        no_blanks = params.reject { |key, value| value.blank? }
        no_blanks.map { |key, value| "#{key}=#{CGI.escape(value.to_s)}" }.join("&")
      end

      def add_amount(post, money, options)
        post[:amount] = amount(money)
        post[:currency] = (options[:currency] || currency(money))
      end

      def preauth(authorization)
        authorization.split(";").last
      end

      def transaction_id(authorization)
        authorization.split(';').first
      end

      RESPONSE_CODES = {
        10001 => "Undefined response",
        10002 => "Waiting for something",
        11000 => "Retry request at a later time",

        20000 => "Operation successful",
        20100 => "Funds held by acquirer",
        20101 => "Funds held by acquirer because merchant is new",
        20200 => "Transaction reversed",
        20201 => "Reversed due to chargeback",
        20202 => "Reversed due to money-back guarantee",
        20203 => "Reversed due to complaint by buyer",
        20204 => "Payment has been refunded",
        20300 => "Reversal has been canceled",

        30000 => "Transaction still in progress",
        30100 => "Transaction has been accepted",
        31000 => "Transaction pending",
        31100 => "Pending due to address",
        31101 => "Pending due to uncleared eCheck",
        31102 => "Pending due to risk review",
        31103 => "Pending due regulatory review",
        31104 => "Pending due to unregistered/unconfirmed receiver",
        31200 => "Pending due to unverified account",
        31201 => "Pending due to non-captured funds",
        31202 => "Pending due to international account (accept manually)",
        31203 => "Pending due to currency conflict (accept manually)",
        31204 => "Pending due to fraud filters (accept manually)",


        40000 => "Problem with transaction data",
        40001 => "Problem with payment data",
        40002 => "Invalid checksum",
        40100 => "Problem with credit card data",
        40101 => "Problem with CVV",
        40102 => "Card expired or not yet valid",
        40103 => "Card limit exceeded",
        40104 => "Card is not valid",
        40105 => "Expiry date not valid",
        40106 => "Credit card brand required",
        40200 => "Problem with bank account data",
        40201 => "Bank account data combination mismatch",
        40202 => "User authentication failed",
        40300 => "Problem with 3-D Secure data",
        40301 => "Currency/amount mismatch",
        40400 => "Problem with input data",
        40401 => "Amount too low or zero",
        40402 => "Usage field too long",
        40403 => "Currency not allowed",
        40410 => "Problem with shopping cart data",
        40420 => "Problem with address data",
        40500 => "Permission error with acquirer API",
        40510 => "Rate limit reached for acquirer API",

        50000 => "Problem with back end",
        50001 => "Country blacklisted",
        50002 => "IP address blacklisted",
        50004 => "Live mode not allowed",
        50005 => "Insufficient permissions (API key)",
        50100 => "Technical error with credit card",
        50101 => "Error limit exceeded",
        50102 => "Card declined",
        50103 => "Manipulation or stolen card",
        50104 => "Card restricted",
        50105 => "Invalid configuration data",
        50200 => "Technical error with bank account",
        50201 => "Account blacklisted",
        50300 => "Technical error with 3-D Secure",
        50400 => "Declined because of risk issues",
        50401 => "Checksum was wrong",
        50402 => "Bank account number was invalid (formal check)",
        50403 => "Technical error with risk check",
        50404 => "Unknown error with risk check",
        50405 => "Unknown bank code",
        50406 => "Open chargeback",
        50407 => "Historical chargeback",
        50408 => "Institution / public bank account (NCA)",
        50409 => "KUNO/Fraud",
        50410 => "Personal Account Protection (PAP)",
        50420 => "Rejected due to acquirer fraud settings",
        50430 => "Rejected due to acquirer risk settings",
        50440 => "Failed due to restrictions with acquirer account",
        50450 => "Failed due to restrictions with user account",
        50500 => "General timeout",
        50501 => "Timeout on side of the acquirer",
        50502 => "Risk management transaction timeout",
        50600 => "Duplicate operation",
        50700 => "Cancelled by user",
        50710 => "Failed due to funding source",
        50711 => "Payment method not usable, use other payment method",
        50712 => "Limit of funding source was exceeded",
        50713 => "Means of payment not reusable (canceled by user)",
        50714 => "Means of payment not reusable (expired)",
        50720 => "Rejected by acquirer",
        50730 => "Transaction denied by merchant",
        50800 => "Preauthorisation failed",
        50810 => "Authorisation has been voided",
        50820 => "Authorisation period expired"
      }

      def response_message(parsed_response)
        return parsed_response["error"] if parsed_response["error"]
        return "Transaction approved." if (parsed_response['data'] == [])

        code = parsed_response["data"]["response_code"].to_i
        RESPONSE_CODES[code] || code.to_s
      end


      class ResponseParser
        attr_reader :raw_response, :parsed, :succeeded, :message, :options

        def initialize(raw_response="", options={})
          @raw_response = raw_response
          @options = options
        end

        def generate_response
          parse_response
          if parsed['error']
            handle_response_parse_error
          else
            handle_response_correct_parsing
          end

          Response.new(succeeded, message, parsed, options)
        end

        private

        def parse_response
          @parsed = JSON.parse(raw_response.sub(/jsonPFunction\(/, '').sub(/\)\z/, ''))
        end

        def handle_response_parse_error
          @succeeded = false
          @message = parsed['error']['message']
        end

        def handle_response_correct_parsing
          @message = parsed['transaction']['processing']['return']['message']
          if @succeeded = is_ack?
            @options[:authorization] = parsed['transaction']['identification']['uniqueId']
          end
        end

        def is_ack?
          parsed['transaction']['processing']['result'] == 'ACK'
        end
      end
    end
  end
end