Merge pull request #1709 from internetee/1708-business-registry-endpoint

Add registrant api companies endpoint

app/controllers/api/v1/registrant/companies_controller.rb

@@ -0,0 +1,52 @@
+require 'serializers/registrant_api/company'
+
+module Api
+  module V1
+    module Registrant
+      class CompaniesController < ::Api::V1::Registrant::BaseController
+        MAX_LIMIT = 200
+        MIN_OFFSET = 0
+
+        def index
+          result = error_result('limit') if limit > MAX_LIMIT || limit < 1
+          result = error_result('offset') if offset < MIN_OFFSET
+          result ||= companies_result(limit, offset)
+
+          render result
+        end
+
+        def current_user_companies
+          current_registrant_user.companies
+        rescue CompanyRegister::NotAvailableError
+          []
+        end
+
+        def limit
+          (params[:limit] || MAX_LIMIT).to_i
+        end
+
+        def offset
+          (params[:offset] || MIN_OFFSET).to_i
+        end
+
+        def error_result(attr_name)
+          { json: { errors: [{ attr_name.to_sym => ['parameter is out of range'] }] },
+            status: :bad_request }
+        end
+
+        def companies_result(limit, offset)
+          @companies = current_user_companies.drop(offset).first(limit)
+          status = @companies.present? ? :ok : :not_found
+
+          serialized_companies = @companies.map do |item|
+            country_code = current_registrant_user.country.alpha3
+            serializer = ::Serializers::RegistrantApi::Company.new(company: item,
+                                                                   country_code: country_code)
+            serializer.to_json
+          end
+          { json: { companies: serialized_companies }, status: status }
+        end
+      end
+    end
+  end
+end