frizbee/kasikornbank

require "kasikornbank/version"
require "kasikornbank/response"
require "kasikornbank/configuration"
require 'digest/md5'

module Kasikornbank
  class << self
    attr_accessor :configuration
  end

  def self.configure
    self.configuration ||= Configuration.new
    yield(configuration)
  end

  class Render
    @@fillspace = "Y"
    @@kbank_url = "https://rt05.kasikornbank.com/pggroup/payment.aspx"
    attr_accessor :args

    def initialize(*args)
      @args = args
    end

    def form
      form = "<form name='sendform' method='post' action='#{@@kbank_url}'>"
      form << "<input type='hidden' id=MERCHANT2 name=MERCHANT2 value='#{Kasikornbank.configuration.merchant2}'>"
      form << "<input type='hidden' id=TERM2 name=TERM2 value='#{Kasikornbank.configuration.term2}'>"
      form << "<input type='hidden' id=AMOUNT2 name=AMOUNT2 value='#{amount_in_cents}'>"
      form << "<input type='hidden' id=URL2 name=URL2 value='#{Kasikornbank.configuration.url2}'>"
      form << "<input type='hidden' id=RESPURL name=RESPURL value='#{Kasikornbank.configuration.respurl}'>"
      form << "<input type='hidden' id=IPCUST2 name=IPCUST2 value='#{remote_ip}'>"
      form << "<input type='hidden' id=DETAIL2 name=DETAIL2 value='#{order_details}'>"
      form << "<input type='hidden' id=INVMERCHANT name=INVMERCHANT value='#{invoice_number}'>"
      form << "<input type='hidden' id=FILLSPACE name=FILLSPACE value='#{@@fillspace}'>"
      form << "<input type='hidden' name='SHOPID' id='SHOPID' value='#{shop_id}'>"
      form << "<input type='hidden' id=Payterm2 name=Payterm2 value='#{payterm2}'>"
      form << "<input type='hidden' id='CHECKSUM' name='CHECKSUM' value='#{checksum}'>"
      form << "</form>"
      form << "<script>"
      form << "window.onload = function(){document.forms['sendform'].submit()}"
      form << "</script>"
      form
    end

    def checksum
      # Accoording to the documentation we have to create
      # MD5 checksum. Should be in this order:
      # MERCHANT2 + TERM2 + AMOUNT2 + URL2 + RESURL + IPCUST2 + DETAIL2 + INVMERCHANT + FILLSPACE + SHOPID + PAYTERM2 + MD5 Key
      # Optional fields can be skipped (Fillspace, ShopId, payterm2)
      Digest::MD5.hexdigest(
        "#{Kasikornbank.configuration.merchant2}#{Kasikornbank.configuration.term2}#{amount_in_cents}#{Kasikornbank.configuration.url2}#{Kasikornbank.configuration.respurl}#{remote_ip}#{order_details}#{invoice_number}#{@@fillspace}#{shop_id}#{payterm2}#{Kasikornbank.configuration.kbank_secret}"
      )
    end

    # Invoice numebr
    # should be Numeric
    # should be 12 digits long
    def invoice_number
      sprintf("%012d",@args[0][:invmerchant])
    end

    # Field DETAIL2
    # Order detail name
    # e.g. Electric Fan - Toshiba Model CM203
    def order_details
      @args[0][:details2]
    end

    # Optional
    # Shop ID. for payment template
    def shop_id
      @args[0][:shop_id]
    end

    # Optional
    # Number of month for installment
    # 2 digits = 3,6,10 month
    def payterm2
      @args[0][:payterm2]
    end

    # Get the client's IP address
    def remote_ip
      # This can be used with api.ipify.org service
      # public_ip = `curl https://api.ipify.org`
      # Extra call not worth it
      @args[0][:ip_address]
    end

    # Amount should be converted
    # to be in cents before send to KBank
    # 10.99 * 100 = 1099
    # Should be 12 digits number
    def amount_in_cents
      amount = (@args[0][:amount].to_f * 100).to_i
      sprintf("%012d",amount)
    end
  end
end