require 'faraday'
require 'json'

module Gcen
  module Client
    class API
      API_HOST = 'https://gcen.i-dash.co.uk/Api/'

      attr_reader :gcen_token

      # Authentication
      #
      # With each request, You must send an extra HTTP header, 'Authentication'
      # We suggest using JSON as the data transfer type, hence you should set the Content Type to application/json
      # All API requests must be made over HTTPS in POST format.
      def initialize(gcen_token:)
        @gcen_token = gcen_token
      end

      # AML Registration
      # This method will register a client with GCEN
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/AMLRegister
      def aml_register(params:)
        post_request('AMLRegister', params)
      end

      # GCS Balance
      # This method will return the GCS balance for a given client's currency
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/GCSBalance
      def gcs_balance(client_id:, currency:)
        post_request('GCSBalance', {
          ClientId: client_id,
          Currency: currency
        })
      end

      # Bank transfer deposit
      # Instructs GCEN of impending bank transfer deposit. Supplies the bank details and reference necessary.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/InvestmentDeposit
      def investment_deposit(params:)
        post_request('InvestmentDeposit', params)
      end

      # Card Payment Deposit
      # Make an investment/deposit by credit/debit card.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/CardPayment
      def card_payment(params:)
        post_request('CardPayment', params)
      end

      # Check Card Payment Response
      # This method checks whether a card payment was authorised and payment was successfully taken.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/CheckCardPaymentResponse
      def check_card_payment_response(ref:, return_mac:)
        post_request('CheckCardPaymentResponse', {
          REF: ref,
          RETURNMAC: return_mac
        })
      end

      # Payment return from balance
      # Instructs GCEN to make a payment out using one of the clients' GCS balances.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/PaymentReturnFromGCSBalance
      def payment_return_from_gcs_balance(params:)
        post_request('PaymentReturnFromGCSBalance', params)
      end

      # GCS Balance Transfer
      # Instructs GCEN to move money from one GCS client balance to another. Internally, GCEN
      # creates a virutal deal for the "FromClient". Money is moved from the "FromClient" balance to
      # the virtual deal, and money is moved from the virutal deal to the "ToClient" balance.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/GCSBalanceTransfer
      def gcs_balance_transfer(params:)
        post_request('GCSBalanceTransfer', params)
      end

      # FX Quote
      # Generates a unique quote from GCEN to exchange currency. Returns an FX Online Deal
      # Quotation with a quotation reference. Quote is valid for purchase up to 30 minutes.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/GetFXQuote
      def get_fx_quote(params:)
        post_request('GetFXQuote', params)
      end

      # Confirm FX Quote - Card Payment
      # This method confirms a given FX quote and sets up the payment system so the user can
      # place their transaction.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/ConfirmQuoteWithCardPayment
      def confirm_quote_with_card_payment(params:)
        post_request('ConfirmQuoteWithCardPayment', params)
      end

      # Confirm FX Quote - Bank Transfer
      # This method confirms a given FX quote and returns the amount and bank account that the
      # client must pay in to.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/ConfirmQuoteWithBankTransfer
      def confirm_quote_with_bank_transfer(params:)
        post_request('ConfirmQuoteWithBankTransfer', params)
      end

      # Credit GCS Balance
      # Makes a manual adjustment to a client's GCS balance.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/CreditGCSBalance
      def credit_gcs_balance(client_id:, currency:, amount:)
        post_request('CreditGCSBalance', {
          ClientId: client_id,
          Currency: currency,
          Amount:   amount
        })
      end

      # Upload Documentation
      # This method allows you to send GCEN the client's Id documents for them to verify and
      # confirm the identity of the client.
      #
      # @since 0.1.0
      #
      # @see https://app.gcen.co.uk/Api/UploadIdDocuments
      def upload_id_documents(client_id:, document_1:, document_2:)
        post_request('UploadIdDocuments', {
          ClientId:  client_id,
          Document1: document_1,
          Document2: document_2
        })
      end

      private

        def post_request(endpoint_name, body, content_type='application/json')
          http = Faraday.new(url: API_HOST) do |param|
            param.headers['Authentication'] = gcen_token
            param.adapter Faraday.default_adapter
          end

          response = http.post do |request|
            request.url endpoint_name

            request.body = body.to_json
            request.headers['Content-Type'] = content_type
          end

          JSON.parse(response.body)
        end
    end
  end
end