fairmondo/fairmondo

#   Copyright (c) 2012-2017, Fairmondo eG.  This file is
#   licensed under the GNU Affero General Public License version 3 or later.
#   See the COPYRIGHT file for details.

module ArticleConcerns
  module FeesAndDonations
    extend ActiveSupport::Concern

    TRANSACTION_FEES = {
      min: 10,
      max_fair: 1_500,
      max_default: 3_000,
      fair: 0.03,
      default: 0.06
    }

    included do
      before_create :set_friendly_percent_for_ngo, if: :seller_ngo

      # Fees and donations
      monetize :calculated_fair_cents, allow_nil: true
      monetize :calculated_friendly_cents, allow_nil: true
      monetize :calculated_fee_cents, allow_nil: true

      ## friendly percent
      validates :friendly_percent_organisation_id, presence: true, if: :friendly_percent_gt_0?
      validates :friendly_percent, presence: true
    end

    ## -------------- Calculate Fees And Donations ---------------

    def could_be_book_price_agreement?
      book_category_id = EXCEPTIONS_ON_FAIRMONDO['book_price_agreement']['category'].to_i
      is_a_book = categories.map { |c| c.self_and_ancestors.map(&:id) }.flatten.include? book_category_id
      is_a_book && condition == 'new'
    end

    def calculated_fees_and_donations
      calculated_fair + calculated_friendly + calculated_fee
    end

    def calculated_fees_and_donations_with_quantity
      calculated_fees_and_donations * quantity
    end

    def calculated_fees_and_donations_netto
      fee_cents = calculated_fair_cents + calculated_friendly_cents + calculated_fee_cents
      netto = Money.new((fee_cents / 1.19).ceil)
      netto
    end

    def calculated_fees_and_donations_netto_with_quantity
      calculated_fees_and_donations_netto * quantity
    end

    def calculate_fees_and_donations
      self.calculated_friendly = Money.new(friendly_percent_result_cents)
      if friendly_percent < 100 && price > 0
        self.calculated_fair = fair_percent_result
        self.calculated_fee = fee_result
      else
        self.calculated_fair = 0
        self.calculated_fee = 0
      end
    end

    private

    def friendly_percent_gt_0?
      friendly_percent.present? &&
      friendly_percent > 0
    end

    def set_friendly_percent_for_ngo
      if seller.ngo
        self.friendly_percent = 100
        self.friendly_percent_organisation_id = seller.id
      end
    end

    def friendly_percent_result_cents
      # At the moment there is no friendly percent
      # for rounding -> always round up (e.g. 900,1 cents are 901 cents)
      # (price_cents * (friendly_percent / 100.0)).ceil
      # NGOs are not allowed to give donation to other NGO
      seller.ngo ? 0 : (price_cents * (friendly_percent / 100.0)).ceil
    end

    ## fees and donations

    def fair_percentage
      seller.ngo ? 0 : 0.01
    end

    def fair_percent_result
      # for rounding -> always round up (e.g. 900,1 cents are 901 cents)
      Money.new(((price_cents - friendly_percent_result_cents) * fair_percentage).ceil)
    end

    def fee_percentage
      return 0 if seller.ngo
      return TRANSACTION_FEES[:fair] if fair?
      TRANSACTION_FEES[:default]
    end

    def fee_result
      result = 0
      result = fee_for_article unless seller.ngo
      result
    end

    def fee_for_article
      result = actual_fee
      result = min_fee if result < min_fee
      result = max_fee if result > max_fee
      result
    end

    def actual_fee
      # for rounding -> always round up (e.g. 900,1 cents are 901 cents)
      Money.new(((price_cents - friendly_percent_result_cents) * fee_percentage).ceil)
    end

    def max_fee
      Money.new(fair? ? TRANSACTION_FEES[:max_fair] : TRANSACTION_FEES[:max_default])
    end

    def min_fee
      Money.new(TRANSACTION_FEES[:min])
    end
  end
end