require 'net/http'
require 'net/https'
require 'uri'
require 'active_support/core_ext/hash/indifferent_access'
class Hash
  include ActiveSupport::CoreExtensions::Hash::IndifferentAccess
end

# TrustCommerce (http://www.trustcommerce.com) is a payment gateway providing credit card
# processing and subscription/recurring billing services.
#
# TrustCommerce implements recurring billing through a service named Citadel
# (http://www.trustcommerce.com/citadel.php).
#
# Merchants create a billing profile through Citadel including customer information,
# credit card data, and billing frequency.  Citadel stores the information and issues the 
# merchant a Billing ID.  A Billing ID is a six-character alphanumeric string identifying 
# the customer profile.
#
# Merchants can modify the customer's information, credit card data, or billing frequency
# anytime using the issued Billing ID.
#
# This plugin provides a simple interface to create, edit, and delete subscriptions
# using the TrustCommerce Citadel API.
#
# It is recommended to download and install the TCLink ruby extension
# (http://www.trustcommerce.com/tclink.php).
# This extension provides failover capability and enhanced security features.
# If this library is not installed, standard POST over SSL will be used.
class TrustCommerceGateway

  # When you signup for a TrustCommerce account you are issued a custid and a password.
  # These are your credentials when using the Citadel API.
  #
  # IMPORTANT NOTE REGARDING PASSWORDS
  # The password that TrustCommerce issues never changes or expires when used through the tclink
  # extension.  However if you choose to use ssl over http instead (the fallback option if the tclink
  # library is not installed), be aware that you need to set the password to your vault password.
  # Likewise, if your application uses the query() method you must set the vault_password.
  # The reason is that TrustCommerce currently routes these query() calls through the vault 
  # and therefore your password must be set accordingly.  To make matters more complicated, 
  # TrustCommerce currently forces you to change the vault password every 90 days.
  #
  # Override these default values with your issued credentials in your app's environment.rb
  #
  # environment.rb
  #   ...
  #   TrustCommerceGateway.custid   = 'your_custid'
  #   TrustCommerceGateway.password = 'your_password'
  #
  #   # (optional) Sets vault password for use in query() calls
  #   TrustCommerceGateway.vault_password = 'your_vault_password'
  #   ...
  class << self
    attr_accessor :custid
    attr_accessor :password
    attr_accessor :vault_password
    def vault_password
      @vault_password || password
    end    
  end
  self.custid   = 'TestMerchant'
  self.password = 'password'
  
  # Settings for standard POST over SSL 
  # Only used if TCLink library is not installed
  API_SETTINGS = { 
    :domain => 'vault.trustcommerce.com',
    :query_path => '/query/', 
    :trans_path => '/trans/', 
    :port => 443  
  }
  
  class Subscription

    # Creates a customer profile and returns a hash.
    # 
    # response = TrustCommerceGateway::Subscription.create(
    #   :cc =>        '4111111111111111', 
    #   :exp =>       '0412', 
    #   :name =>      'Jennifer Smith',
    # 	:amount =>		1200,
    # 	:cycle =>		  '1m',
    #   :demo =>      'y'
    # )
    #
    # if response['status'] == 'approved'
    #   puts "Customer profile created with Billing ID: #{response['billingid']}"
    # else
    #   puts "An error occurred: #{response['error']}"
    # end
    def self.create(options)
      return TrustCommerceGateway.send_request(options.merge(:action => 'store'))
    end
    
    # Updates a customer profile and returns a hash.
    # 
    # response = TrustCommerceGateway::Subscription.update(
    #   :billingid => create_response['billingid'],
    #   :cc =>        '5411111111111115', 
    #   :exp =>       '0412'
    # )
    #
    # if response['status'] == 'accepted'
    #   puts "Customer profile updated"
    # else
    #   puts "An error occurred: #{response['error']}"
    # end
    def self.update(options)
      return TrustCommerceGateway.send_request(options.merge(:action => 'store'))
    end    
    
    # Removes a customer profile from active use and returns a hash.
    #
    # response = TrustCommerceGateway::Subscription.destroy(
    #   :billingid => '123456'
    # )
    #
    # if response['status'] == 'accepted'
    #   puts 'Customer profile removed from active use'
    # else
    #   puts 'An error occurred'
    # end
    def self.destroy(options)
      return TrustCommerceGateway.send_request(options.merge(:action => 'unstore'))
    end
    
    # Process a one-time sale against a Billing ID
    # 
    # response = TrustCommerceGateway::Subscription.charge(
    #   :billingid  => 'ABC123',
    #   :amount     => 1995,
    # )
    def self.charge(options)
      return TrustCommerceGateway.send_request(options.merge(:action => 'sale'))
    end
    
    # Process a credit against a transaction
    # 
    # response = TrustCommerceGateway::Subscription.credit(
    #   :transid  => '001-0000111101',
    #   :amount   => 1995,
    # )
    def self.credit(options)
      return TrustCommerceGateway.send_request(options.merge(:action => 'credit'))
    end
    
    # Query the Vault API
    #
    # More information at https://vault.trustcommerce.com/downloads/TCDevGuide.html#query
    #    
    # # returns list of sale transactions in CSV format for customer ABC123
    # query_response = TrustCommerceGateway::Subscription.query(
    #   :querytype  => 'transaction',
    #   :action     => 'sale',
    #   :billingid  => 'ABC123'
    # )  
    def self.query(options)
      return TrustCommerceGateway.send_query(options)
    end    
    
  end
  
  # Checks if TCLink library (http://www.trustcommerce.com/tclink.php) is installed.
  def self.tclink?
    begin
      require 'tclink'
      true
    rescue LoadError
      false
    end
  end
  
  private
  
    def self.clean_parameters(hash)
      hash.keys.inject({}) { |h,k| h[k.to_s] = hash[k].to_s; h }
    end

    def self.send_request(options)
      options[:custid]    = self.custid
      options[:password]  = self.password
      options.update(:demo => 'y') if ENV['RAILS_ENV'] != 'production'
      parameters = clean_parameters(options)
      if tclink? # use TCLink extension if installed
        return TCLink.send(parameters).with_indifferent_access
      else # TCLink library not installed - use https post
        parameters[:password] = self.vault_password.to_s
        response = send_https_request(API_SETTINGS[:trans_path], parameters)
        
        # --- [ parse response ] ---
        results = {}
        lines = response.body.split("\n")
        lines.each do |line|
          k, v = line.split('=')
          results[k] = v
        end
        return results.with_indifferent_access
      end
    end
    
    def self.send_query(options)
      options[:custid]    = self.custid
      options[:password]  = self.vault_password.to_s
      response = send_https_request(API_SETTINGS[:query_path], clean_parameters(options))
    end
    
    def self.send_https_request(path, parameters)
      http = Net::HTTP.new(API_SETTINGS[:domain], API_SETTINGS[:port])
      http.use_ssl = true
      http.verify_mode = OpenSSL::SSL::VERIFY_NONE # avoid ssl cert warning
      request = Net::HTTP::Post.new(path)
      request.form_data = parameters
      http.request(request)
    end    

end