From aa46a4b5da84ed1487467456c11aba1c7f531eee Mon Sep 17 00:00:00 2001
From: Luis Ramos <luisramos0@gmail.com>
Date: Fri, 7 Aug 2020 18:44:04 +0100
Subject: [PATCH] Bring models related to taxes and adjustments from spree_core

---
 app/models/spree/adjustment.rb         | 121 ++++++++++++++
 app/models/spree/calculator.rb         |  39 +++++
 app/models/spree/tax_category.rb       |  18 +++
 app/models/spree/tax_rate.rb           |  86 ++++++++++
 spec/models/spree/adjustment_spec.rb   | 210 +++++++++++++++++++++++++
 spec/models/spree/tax_category_spec.rb |  27 ++++
 6 files changed, 501 insertions(+)
 create mode 100644 app/models/spree/adjustment.rb
 create mode 100644 app/models/spree/calculator.rb
 create mode 100644 app/models/spree/tax_category.rb
 create mode 100644 app/models/spree/tax_rate.rb
 create mode 100644 spec/models/spree/tax_category_spec.rb

diff --git a/app/models/spree/adjustment.rb b/app/models/spree/adjustment.rb
new file mode 100644
index 0000000000..9168d55429
--- /dev/null
+++ b/app/models/spree/adjustment.rb
@@ -0,0 +1,121 @@
+# Adjustments represent a change to the +item_total+ of an Order. Each adjustment
+# has an +amount+ that can be either positive or negative.
+#
+# Adjustments can be open/closed/finalized
+#
+# Once an adjustment is finalized, it cannot be changed, but an adjustment can
+# toggle between open/closed as needed
+#
+# Boolean attributes:
+#
+# +mandatory+
+#
+# If this flag is set to true then it means the the charge is required and will not
+# be removed from the order, even if the amount is zero. In other words a record
+# will be created even if the amount is zero. This is useful for representing things
+# such as shipping and tax charges where you may want to make it explicitly clear
+# that no charge was made for such things.
+#
+# +eligible?+
+#
+# This boolean attributes stores whether this adjustment is currently eligible
+# for its order. Only eligible adjustments count towards the order's adjustment
+# total. This allows an adjustment to be preserved if it becomes ineligible so
+# it might be reinstated.
+module Spree
+  class Adjustment < ActiveRecord::Base
+    belongs_to :adjustable, polymorphic: true
+    belongs_to :source, polymorphic: true
+    belongs_to :originator, polymorphic: true
+
+    validates :label, presence: true
+    validates :amount, numericality: true
+
+    after_save :update_adjustable
+    after_destroy :update_adjustable
+
+    state_machine :state, initial: :open do
+      event :close do
+        transition from: :open, to: :closed
+      end
+
+      event :open do
+        transition from: :closed, to: :open
+      end
+
+      event :finalize do
+        transition from: [:open, :closed], to: :finalized
+      end
+    end
+
+    scope :tax, -> { where(originator_type: 'Spree::TaxRate', adjustable_type: 'Spree::Order') }
+    scope :price, -> { where(adjustable_type: 'Spree::LineItem') }
+    scope :shipping, -> { where(originator_type: 'Spree::ShippingMethod') }
+    scope :optional, -> { where(mandatory: false) }
+    scope :eligible, -> { where(eligible: true) }
+    scope :charge, -> { where('amount >= 0') }
+    scope :credit, -> { where('amount < 0') }
+    scope :promotion, -> { where(originator_type: 'Spree::PromotionAction') }
+    scope :return_authorization, -> { where(source_type: "Spree::ReturnAuthorization") }
+
+    def promotion?
+      originator_type == 'Spree::PromotionAction'
+    end
+
+    # Update the boolean _eligible_ attribute which determines which adjustments
+    # count towards the order's adjustment_total.
+    def set_eligibility
+      result = mandatory || ((amount != 0 || promotion?) && eligible_for_originator?)
+      update_column(:eligible, result)
+    end
+
+    # Allow originator of the adjustment to perform an additional eligibility of the adjustment
+    # Should return _true_ if originator is absent or doesn't implement _eligible?_
+    def eligible_for_originator?
+      return true if originator.nil?
+      !originator.respond_to?(:eligible?) || originator.eligible?(source)
+    end
+
+    # Update both the eligibility and amount of the adjustment. Adjustments
+    # delegate updating of amount to their Originator when present, but only if
+    # +locked+ is false. Adjustments that are +locked+ will never change their amount.
+    #
+    # Adjustments delegate updating of amount to their Originator when present,
+    # but only if when they're in "open" state, closed or finalized adjustments
+    # are not recalculated.
+    #
+    # It receives +calculable+ as the updated source here so calculations can be
+    # performed on the current values of that source. If we used +source+ it 
+    # could load the old record from db for the association. e.g. when updating
+    # more than on line items at once via accepted_nested_attributes the order
+    # object on the association would be in a old state and therefore the
+    # adjustment calculations would not performed on proper values
+    def update!(calculable = nil)
+      return if immutable?
+      # Fix for #3381
+      # If we attempt to call 'source' before the reload, then source is currently
+      # the order object. After calling a reload, the source is the Shipment.
+      reload
+      originator.update_adjustment(self, calculable || source) if originator.present?
+      set_eligibility
+    end
+
+    def currency
+      adjustable ? adjustable.currency : Spree::Config[:currency]
+    end
+
+    def display_amount
+      Spree::Money.new(amount, { currency: currency })
+    end
+
+    def immutable?
+      state != "open"
+    end
+
+    private
+
+      def update_adjustable
+        adjustable.update! if adjustable.is_a? Order
+      end
+  end
+end
diff --git a/app/models/spree/calculator.rb b/app/models/spree/calculator.rb
new file mode 100644
index 0000000000..b9aeed3333
--- /dev/null
+++ b/app/models/spree/calculator.rb
@@ -0,0 +1,39 @@
+module Spree
+  class Calculator < ActiveRecord::Base
+    belongs_to :calculable, polymorphic: true
+
+    # This method must be overriden in concrete calculator.
+    #
+    # It should return amount computed based on #calculable and/or optional parameter
+    def compute(something = nil)
+      raise NotImplementedError, 'please use concrete calculator'
+    end
+
+    # overwrite to provide description for your calculators
+    def self.description
+      'Base Calculator'
+    end
+
+    ###################################################################
+
+    def self.register(*klasses)
+    end
+
+    # Returns all calculators applicable for kind of work
+    def self.calculators
+      Rails.application.config.spree.calculators
+    end
+
+    def to_s
+      self.class.name.titleize.gsub("Calculator\/", "")
+    end
+
+    def description
+      self.class.description
+    end
+
+    def available?(object)
+      true
+    end
+  end
+end
diff --git a/app/models/spree/tax_category.rb b/app/models/spree/tax_category.rb
new file mode 100644
index 0000000000..6e0dd27da1
--- /dev/null
+++ b/app/models/spree/tax_category.rb
@@ -0,0 +1,18 @@
+module Spree
+  class TaxCategory < ActiveRecord::Base
+    acts_as_paranoid
+    validates :name, presence: true, uniqueness: { scope: :deleted_at }
+
+    has_many :tax_rates, dependent: :destroy
+
+    before_save :set_default_category
+
+    def set_default_category
+      #set existing default tax category to false if this one has been marked as default
+
+      if is_default && tax_category = self.class.where(is_default: true).first
+        tax_category.update_column(:is_default, false) unless tax_category == self
+      end
+    end
+  end
+end
diff --git a/app/models/spree/tax_rate.rb b/app/models/spree/tax_rate.rb
new file mode 100644
index 0000000000..fde950b3cd
--- /dev/null
+++ b/app/models/spree/tax_rate.rb
@@ -0,0 +1,86 @@
+module Spree
+  class DefaultTaxZoneValidator < ActiveModel::Validator
+    def validate(record)
+      if record.included_in_price
+        record.errors.add(:included_in_price, Spree.t(:included_price_validation)) unless Zone.default_tax
+      end
+    end
+  end
+end
+
+module Spree
+  class TaxRate < ActiveRecord::Base
+    acts_as_paranoid
+    include Spree::Core::CalculatedAdjustments
+    belongs_to :zone, class_name: "Spree::Zone"
+    belongs_to :tax_category, class_name: "Spree::TaxCategory"
+
+    validates :amount, presence: true, numericality: true
+    validates :tax_category_id, presence: true
+    validates_with DefaultTaxZoneValidator
+
+    scope :by_zone, ->(zone) { where(zone_id: zone) }
+
+    # Gets the array of TaxRates appropriate for the specified order
+    def self.match(order)
+      return [] unless order.tax_zone
+      all.select do |rate|
+        (!rate.included_in_price && (rate.zone == order.tax_zone || rate.zone.contains?(order.tax_zone) || (order.tax_address.nil? && rate.zone.default_tax))) ||
+        (rate.included_in_price && !order.tax_address.nil? && !rate.zone.contains?(order.tax_zone) && rate.zone.default_tax)
+      end
+    end
+
+    def self.adjust(order)
+      order.adjustments.tax.destroy_all
+      order.line_item_adjustments.where(originator_type: 'Spree::TaxRate').destroy_all
+
+      self.match(order).each do |rate|
+        rate.adjust(order)
+      end
+    end
+
+    # For Vat the default rate is the rate that is configured for the default category
+    # It is needed for every price calculation (as all customer facing prices include vat )
+    # The function returns the actual amount, which may be 0 in case of wrong setup, but is never nil
+    def self.default
+      category = TaxCategory.includes(:tax_rates).where(is_default: true).first
+      return 0 unless category
+
+      address ||= Address.new(country_id: Spree::Config[:default_country_id])
+      rate = category.tax_rates.detect { |rate| rate.zone.include? address }.try(:amount)
+
+      rate || 0
+    end
+
+    # Creates necessary tax adjustments for the order.
+    def adjust(order)
+      label = create_label
+      if included_in_price
+        if Zone.default_tax.contains? order.tax_zone
+          order.line_items.each { |line_item| create_adjustment(label, line_item, line_item) }
+        else
+          amount = -1 * calculator.compute(order)
+          label = Spree.t(:refund) + label
+
+          order.adjustments.create(
+            amount: amount,
+            source: order,
+            originator: self,
+            state: "closed",
+            label: label
+          )
+        end
+      else
+        create_adjustment(label, order, order)
+      end
+    end
+
+    private
+
+      def create_label
+        label = ""
+        label << (name.present? ? name : tax_category.name) + " "
+        label << (show_rate_in_label? ? "#{amount * 100}%" : "")
+      end
+  end
+end
diff --git a/spec/models/spree/adjustment_spec.rb b/spec/models/spree/adjustment_spec.rb
index 0ea3eea273..123ece3534 100644
--- a/spec/models/spree/adjustment_spec.rb
+++ b/spec/models/spree/adjustment_spec.rb
@@ -2,6 +2,216 @@ require 'spec_helper'
 
 module Spree
   describe Adjustment do
+    let(:order) { mock_model(Spree::Order, update!: nil) }
+    let(:adjustment) { Spree::Adjustment.create(:label => "Adjustment", :amount => 5) }
+
+    describe "scopes" do
+      let!(:arbitrary_adjustment) { create(:adjustment, source: nil, label: "Arbitrary") }
+      let!(:return_authorization_adjustment) { create(:adjustment, source: create(:return_authorization)) }
+
+      it "returns return_authorization adjustments" do
+        expect(Spree::Adjustment.return_authorization.to_a).to eq [return_authorization_adjustment]
+      end
+    end
+
+    context "#update!" do
+      context "when originator present" do
+        let(:originator) { double("originator", update_adjustment: nil) }
+        before do
+          originator.stub update_amount: true
+          adjustment.stub originator: originator, label: 'adjustment', amount: 0
+        end
+        it "should do nothing when closed" do
+          adjustment.close
+          originator.should_not_receive(:update_adjustment)
+          adjustment.update!
+        end
+        it "should do nothing when finalized" do
+          adjustment.finalize
+          originator.should_not_receive(:update_adjustment)
+          adjustment.update!
+        end
+        it "should set the eligibility" do
+          adjustment.should_receive(:set_eligibility)
+          adjustment.update!
+        end
+        it "should ask the originator to update_adjustment" do
+          originator.should_receive(:update_adjustment)
+          adjustment.update!
+        end
+      end
+      it "should do nothing when originator is nil" do
+        adjustment.stub originator: nil
+        adjustment.should_not_receive(:amount=)
+        adjustment.update!
+      end
+    end
+
+    context "#promotion?" do
+      it "returns false if not promotion adjustment" do
+        expect(adjustment.promotion?).to eq false
+      end
+
+      it "returns true if promotion adjustment" do
+        adjustment.originator_type = "Spree::PromotionAction"
+        expect(adjustment.promotion?).to eq true
+      end
+    end
+
+    context "#eligible? after #set_eligibility" do
+      context "when amount is 0" do
+        before { adjustment.amount = 0 }
+        it "should be eligible if mandatory?" do
+          adjustment.mandatory = true
+          adjustment.set_eligibility
+          adjustment.should be_eligible
+        end
+        it "should be eligible if `promotion?` even if not `mandatory?`" do
+          adjustment.should_receive(:promotion?).and_return(true)
+          adjustment.mandatory = false
+          adjustment.set_eligibility
+          adjustment.should be_eligible
+        end
+        it "should not be eligible unless mandatory?" do
+          adjustment.mandatory = false
+          adjustment.set_eligibility
+          adjustment.should_not be_eligible
+        end
+      end
+
+      context "when amount is greater than 0" do
+        before { adjustment.amount = 25.00 }
+        it "should be eligible if mandatory?" do
+          adjustment.mandatory = true
+          adjustment.set_eligibility
+          adjustment.should be_eligible
+        end
+        it "should be eligible if not mandatory and eligible for the originator" do
+          adjustment.mandatory = false
+          adjustment.stub(eligible_for_originator?: true)
+          adjustment.set_eligibility
+          adjustment.should be_eligible
+        end
+        it "should not be eligible if not mandatory not eligible for the originator" do
+          adjustment.mandatory = false
+          adjustment.stub(eligible_for_originator?: false)
+          adjustment.set_eligibility
+          adjustment.should_not be_eligible
+        end
+      end
+    end
+
+    context "#save" do
+      it "should call order#update!" do
+        adjustment = Spree::Adjustment.new(
+          :adjustable => order,
+          :amount => 10,
+          :label => "Foo"
+        )
+        order.should_receive(:update!)
+        adjustment.save
+      end
+    end
+
+    context "adjustment state" do
+      let(:adjustment) { create(:adjustment, state: 'open') }
+
+      context "#immutable?" do
+        it "is true when adjustment state isn't open" do
+          adjustment.state = "closed"
+          adjustment.should be_immutable
+          adjustment.state = "finalized"
+          adjustment.should be_immutable
+        end
+
+        it "is false when adjustment state is open" do
+          adjustment.state = "open"
+          adjustment.should_not be_immutable
+        end
+      end
+
+      context "#finalized?" do
+        it "is true when adjustment state is finalized" do
+          adjustment.state = "finalized"
+          adjustment.should be_finalized
+        end
+
+        it "is false when adjustment state isn't finalized" do
+          adjustment.state = "closed"
+          adjustment.should_not be_finalized
+          adjustment.state = "open"
+          adjustment.should_not be_finalized
+        end
+      end
+    end
+
+    context "#eligible_for_originator?" do
+      context "with no originator" do
+        specify { adjustment.should be_eligible_for_originator }
+      end
+      context "with originator that doesn't have 'eligible?'" do
+        before { adjustment.originator = mock_model(Spree::TaxRate) }
+        specify { adjustment.should be_eligible_for_originator }
+      end
+      context "with originator that has 'eligible?'" do
+        let(:originator) { Spree::TaxRate.new }
+        before { adjustment.originator = originator }
+        context "and originator is eligible for order" do
+          before { originator.stub(eligible?: true) }
+          specify { adjustment.should be_eligible_for_originator }
+        end
+        context "and originator is not eligible for order" do
+          before { originator.stub(eligible?: false) }
+          specify { adjustment.should_not be_eligible_for_originator }
+        end
+      end
+    end
+
+    context "#display_amount" do
+      before { adjustment.amount = 10.55 }
+
+      context "with display_currency set to true" do
+        before { Spree::Config[:display_currency] = true }
+
+        it "shows the currency" do
+          adjustment.display_amount.to_s.should == "$10.55 USD"
+        end
+      end
+
+      context "with display_currency set to false" do
+        before { Spree::Config[:display_currency] = false }
+
+        it "does not include the currency" do
+          adjustment.display_amount.to_s.should == "$10.55"
+        end
+      end
+
+      context "with currency set to JPY" do
+        context "when adjustable is set to an order" do
+          before do
+            order.stub(:currency) { 'JPY' }
+            adjustment.adjustable = order
+          end
+
+          it "displays in JPY" do
+            adjustment.display_amount.to_s.should == "¥11"
+          end
+        end
+
+        context "when adjustable is nil" do
+          it "displays in the default currency" do
+            adjustment.display_amount.to_s.should == "$10.55"
+          end
+        end
+      end
+    end
+
+    context '#currency' do
+      it 'returns the globally configured currency' do
+        adjustment.currency.should == 'USD'
+      end
+    end
+
     it "has metadata" do
       adjustment = create(:adjustment, metadata: create(:adjustment_metadata))
       expect(adjustment.metadata).to be
diff --git a/spec/models/spree/tax_category_spec.rb b/spec/models/spree/tax_category_spec.rb
new file mode 100644
index 0000000000..ea2c329aea
--- /dev/null
+++ b/spec/models/spree/tax_category_spec.rb
@@ -0,0 +1,27 @@
+require 'spec_helper'
+
+describe Spree::TaxCategory do
+  context 'default tax category' do
+    let(:tax_category) { create(:tax_category) }
+    let(:new_tax_category) { create(:tax_category) }
+
+    before do
+      tax_category.update_column(:is_default, true)
+    end
+
+    it "should undefault the previous default tax category" do
+      new_tax_category.update_attributes({:is_default => true})
+      new_tax_category.is_default.should be_true
+
+      tax_category.reload
+      tax_category.is_default.should be_false
+    end
+
+    it "should undefault the previous default tax category except when updating the existing default tax category" do
+      tax_category.update_column(:description, "Updated description")
+
+      tax_category.reload
+      tax_category.is_default.should be_true
+    end
+  end
+end