Add formula relations to calculators constructor

app/assets/stylesheets/pages/calculator.scss

@@ -271,6 +271,10 @@ select.custom-select {
       margin: 0;
     }
   }
+  .result-wrapper {
+    display: flex;
+    width: fit-content;
+  }
   .vector-width {
     width: 100px;
     .vector {
@@ -279,6 +283,21 @@ select.custom-select {
     .vector-mobile {
       display: none;
     }
+    .vector-mobile-left {
+      display: none;
+    }
+    .vector-mobile-right {
+      display: none;
+    }
+    .right {
+      padding-left: 30px;
+      padding-top: 85px;
+      transform: translateX(-40px);
+    }
+    .left {
+      padding-bottom: 85px;
+      transform: rotate(180deg) translateX(40px);
+    }
   }
 }
 
@@ -347,6 +366,12 @@ select.custom-select {
     align-items: center;
     max-width: 879px;
 
+    .result-wrapper {
+      display: block;
+      width: 350px;
+      margin-right: 140px;
+      margin-top: 0;
+    }
     .vector-width {
       width: 350px;
       .vector {
@@ -357,6 +382,25 @@ select.custom-select {
         display: block;
         margin: auto;
       }
+      .vector-mobile-left {
+        display: block;
+        margin: auto;
+        transform: rotate(180deg);
+      }
+      .vector-mobile-right {
+        display: block;
+        margin: auto;
+      }
+      .right {
+        display: none;
+        padding-top: 25px;
+        transform: none;
+      }
+      .left {
+        display: none;
+        padding-top: 25px;
+        transform: none;
+      }
     }
   }
 }
@@ -389,6 +433,10 @@ select.custom-select {
     .vector-width {
       width: 300px;
     }
+    .result-wrapper {
+      width: 280px;
+      margin-right: 0;
+    }
   }
 }
 

app/controllers/account/calculators_controller.rb

@@ -82,7 +82,7 @@ def collect_fields_for_kind(kind)
   def calculator_params
     params.require(:calculator).permit(
       :id, :en_name, :uk_name, :color,
-      formulas_attributes: [:id, :expression, :en_label, :uk_label, :calculator_id, :en_unit, :uk_unit, :priority, :_destroy],
+      formulas_attributes: [:id, :expression, :en_label, :uk_label, :calculator_id, :en_unit, :uk_unit, :priority, :relation, :_destroy],
       fields_attributes: [:id, :en_label, :uk_label, :var_name, :kind, :_destroy,
         categories_attributes: [:id, :en_name, :uk_name, :price, :_destroy]]
     )

app/models/calculator.rb

@@ -28,6 +28,8 @@ class Calculator < ApplicationRecord
   has_many :fields, dependent: :destroy
   has_many :formulas, -> { ordered_by_priority }, dependent: :destroy, inverse_of: :calculator
 
+  validates_with RelationValidator
+
   accepts_nested_attributes_for :fields, allow_destroy: true
   accepts_nested_attributes_for :formulas, allow_destroy: true
 

app/services/calculators/calculation_service.rb

@@ -9,8 +9,12 @@ def initialize(calculator, inputs)
   def perform
     @calculator.formulas.map do |formula|
       result = @dentaku.evaluate(formula.expression, @inputs).round(2)
-
-      { label: formula.label, result: result, unit: formula.unit }
+      {
+        label: formula.label,
+        result: result,
+        unit: formula.unit,
+        relation: formula.relation
+      }
     end
   end
 end

app/validators/relation_validator.rb

@@ -0,0 +1,40 @@
+class RelationValidator < ActiveModel::Validator
+  def validate(record)
+    relation_is_correct(record)
+  end
+
+  private
+
+  def relation_is_correct(record)
+    return if record.formulas.blank?
+
+    if record.formulas.first.relation == "previous"
+      record.formulas.first.errors.add(:relation, I18n.t("activerecord.errors.models.formula.attributes.expression.first_relation_error"))
+    end
+
+    if record.formulas.last.relation == "next"
+      record.formulas.last.errors.add(:relation, I18n.t("activerecord.errors.models.formula.attributes.expression.last_relation_error"))
+    end
+
+    last_relation             = nil
+    last_formula_has_relation = false
+
+    record.formulas.each do |formula|
+      if last_relation == "next" && formula.relation == "previous"
+        formula.errors.add(:relation, I18n.t("activerecord.errors.models.formula.attributes.expression.relation_between_two_error"))
+      end
+
+      if last_formula_has_relation && formula.relation == "previous" || last_relation == "next" && formula.relation == "next"
+        formula.errors.add(:relation, I18n.t("activerecord.errors.models.formula.attributes.expression.already_have_relation_error"))
+      end
+
+      last_formula_has_relation = formula.relation.present? || last_relation == "next"
+
+      last_relation = formula.relation
+    end
+
+    if record.formulas.any? { |formula| formula.errors.present? }
+      record.errors.add(:formulas, "contain invalid relations.")
+    end
+  end
+end

app/views/account/calculators/partials/_formula_fields.html.erb

@@ -10,6 +10,8 @@
 
     <%= f.input :uk_unit, label: "Uk Unit Label:" %>
     <%= f.input :en_unit, label: "Unit Label:" %>
+    <%= f.input :relation, as: :select, label: "Relation of formula (optional):",
+        collection: { "None": nil, "Next": "next", "Previous": "previous"}, default: "None" %>
 
     <%= link_to_remove_association "- Remove Formula", f, class: "text-red-500 underline" %>
   </div>

app/views/calculators/partials/_calculation_results.html.erb

@@ -5,7 +5,12 @@
   <h2 class="pt-6 text-2xl font-semibold text-center dynamic-text-color">Calculation Results</h2>
   <div class="jumbotron calculation-results result main-result-container result-container">
     <% results.each do |result| %>
-      <div>
+      <div class="result-wrapper">
+        <% if result[:relation] == "previous" %>
+          <%= render "calculators/partials/show/relation_arrow", locals: {rotate_direction: "left"} %>
+        <% end %>
+
+        <div>
           <%= image_tag "#{formula_image}", class: "img-margin", alt: "icon" %>
           <p class="dynamic-text-color">
             <%= result[:result] %>
@@ -16,6 +21,11 @@
           <p class="diapers-font-text">
             <%= result[:label] %>
           </p>
+        </div>
+
+        <% if result[:relation] == "next" %>
+          <%= render "calculators/partials/show/relation_arrow", locals: {rotate_direction: "right"} %>
+        <% end %>
       </div>
     <% end %>
   </div>

app/views/calculators/partials/show/_relation_arrow.html.erb

@@ -0,0 +1,4 @@
+<div class="vector-width">
+    <%= image_tag "icons/vector_5.png", class: locals[:rotate_direction], alt: "horizontal arrow" %>
+    <%= image_tag "icons/vector_2.png", class: "vector-mobile-#{locals[:rotate_direction]}", alt: "vertical arrow" %>
+</div>

config/locales/en/en.yml

@@ -699,6 +699,10 @@ en:
             expression:
               uninitialized_fields: "has uninitialized fields %{fields}"
               mathematically_invalid: "is mathematically invalid"
+              first_relation_error: "is invalid no previous formula"
+              last_relation_error: "is invalid no next formula"
+              relation_between_two_error: "is invalid this formula already has a relation to the previous one"
+              already_have_relation_error: "is invalid formula can have relation with only one other formula"
     form_errors:
       one: "One error prohibited %{model} from being saved"
       other: "%{count} errors prohibited this %{model} from being saved"

config/locales/uk/uk.yml

@@ -591,6 +591,10 @@ uk:
                 one: "має не ініціалізоване поле %{fields}"
                 other: "має не ініціалізовані поля %{fields}"
               mathematically_invalid: "є математично некоректним"
+              first_relation_error: "некоректний немає попередньої формули"
+              last_relation_error: "некоректний немає наступної формули"
+              relation_between_two_error: "некориктний ця формула вже має зв'язок з попередньою"
+              already_have_relation_error: "формула може мати зв'язок лише з однією іншою формулою"
         calculator:
           attributes:
             name:

db/migrate/20241209084523_add_relation_to_formula.rb

@@ -0,0 +1,5 @@
+class AddRelationToFormula < ActiveRecord::Migration[7.2]
+  def change
+    add_column :formulas, :relation, :string
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2024_12_01_141708) do
+ActiveRecord::Schema[7.2].define(version: 2024_12_09_084523) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "pgcrypto"
   enable_extension "plpgsql"
@@ -134,6 +134,7 @@
     t.bigint "calculator_id", null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
+    t.string "relation"
     t.integer "priority", default: 0, null: false
     t.index ["calculator_id"], name: "index_formulas_on_calculator_id"
   end

spec/helpers/calculators/calculation_service_helper_spec.rb

@@ -6,7 +6,7 @@
   let(:calculator) { instance_double("Calculator", formulas: formulas) }
   let(:formulas) do
     [
-      Formula.new(en_label: "Addition", en_unit: "units", uk_label: "Додавання", uk_unit: "одиниці", expression: "x + y"),
+      Formula.new(en_label: "Addition", en_unit: "units", uk_label: "Додавання", uk_unit: "одиниці", expression: "x + y", relation: "next"),
       Formula.new(en_label: "Multiplication", en_unit: "units", uk_label: "Множення", uk_unit: "одиниці", expression: "x * y")
     ]
   end
@@ -28,8 +28,8 @@
 
       it "returns results with English labels and units" do
         expect(subject).to eq([
-          { label: "Addition", result: 8, unit: "units" },
-          { label: "Multiplication", result: 15, unit: "units" }
+          { label: "Addition", result: 8, unit: "units", relation: "next" },
+          { label: "Multiplication", result: 15, unit: "units", relation: nil }
         ])
       end
     end
@@ -39,8 +39,8 @@
 
       it "returns results with Ukrainian labels and units" do
         expect(subject).to eq([
-          { label: "Додавання", result: 8, unit: "одиниці" },
-          { label: "Множення", result: 15, unit: "одиниці" }
+          { label: "Додавання", result: 8, unit: "одиниці", relation: "next" },
+          { label: "Множення", result: 15, unit: "одиниці", relation: nil }
         ])
       end
     end

spec/validators/relation_validator_spec.rb

@@ -0,0 +1,67 @@
+require "rails_helper"
+
+RSpec.describe RelationValidator do
+  let(:calculator) { build(:calculator) }
+
+  describe "validations" do
+    let(:formula_previous_relation) { build(:formula, relation: "previous") }
+    let(:formula_next_relation) { build(:formula, relation: "next") }
+    let(:formula_none_relation) { build(:formula, relation: nil) }
+
+    context "when the first formula has a relation of previous" do
+      before do
+        calculator.formulas = [formula_previous_relation]
+        calculator.valid?
+      end
+
+      it "adds an error to the first formula" do
+        expect(formula_previous_relation.errors[:relation]).to include(I18n.t("activerecord.errors.models.formula.attributes.expression.first_relation_error"))
+      end
+    end
+
+    context "when the last formula has a relation of next" do
+      before do
+        calculator.formulas = [formula_none_relation, formula_next_relation]
+        calculator.valid?
+      end
+
+      it "adds an error to the last formula" do
+        expect(formula_next_relation.errors[:relation]).to include(I18n.t("activerecord.errors.models.formula.attributes.expression.last_relation_error"))
+      end
+    end
+
+    context "when formulas have consecutive relations 'next' and 'previous'" do
+      before do
+        calculator.formulas = [formula_next_relation, formula_previous_relation]
+        calculator.valid?
+      end
+
+      it "adds an error to the second formula" do
+        expect(formula_previous_relation.errors[:relation]).to include(I18n.t("activerecord.errors.models.formula.attributes.expression.relation_between_two_error"))
+      end
+    end
+
+    context "when fomula already have relation" do
+      before do
+        calculator.formulas = [formula_next_relation, formula_none_relation, formula_previous_relation]
+        calculator.valid?
+      end
+
+      it "adds an error to the second formula" do
+        expect(formula_previous_relation.errors[:relation]).to include(I18n.t("activerecord.errors.models.formula.attributes.expression.already_have_relation_error"))
+      end
+    end
+
+    context "when all formulas have valid relations" do
+      before do
+        calculator.formulas = [formula_next_relation, formula_none_relation, formula_next_relation, formula_none_relation]
+        calculator.valid?
+      end
+
+      it "does not add errors to the formulas" do
+        expect(formula_next_relation.errors[:relation]).to be_empty
+        expect(formula_none_relation.errors[:relation]).to be_empty
+      end
+    end
+  end
+end