Add local_census_records importation model

This model without database allow us to validate incoming file extension and
headers and also does the following during importation process:

* Ignore empty rows
* Classifiy rows in two groups: created_records, invalid_records

app/models/local_census_records/import.rb

@@ -0,0 +1,84 @@
+require "csv"
+
+class LocalCensusRecords::Import
+  include ActiveModel::Model
+
+  ATTRIBUTES = %w[document_type document_number date_of_birth postal_code].freeze
+  ALLOWED_FILE_EXTENSIONS = %w[csv].freeze
+
+  attr_accessor :file, :created_records, :invalid_records
+
+  validates :file, presence: true
+  validate :file_extension, if: -> { @file.present? }
+  validate :file_headers_definition, if: -> { @file.present? && valid_extension? }
+
+  def initialize(attributes = {})
+    if attributes.present?
+      attributes.each do |attr, value|
+        public_send("#{attr}=", value)
+      end
+    end
+    @created_records = []
+    @invalid_records = []
+  end
+
+  def save
+    return false if invalid?
+
+    CSV.open(file.path, headers: true).each do |row|
+      next if empty_row?(row)
+
+      process_row row
+    end
+    true
+  end
+
+  private
+
+    def process_row(row)
+      local_census_record = build_local_census_record(row)
+
+      if local_census_record.invalid?
+        invalid_records << local_census_record
+      else
+        local_census_record.save
+        created_records << local_census_record
+      end
+    end
+
+    def build_local_census_record(row)
+      local_census_record = LocalCensusRecord.new
+      local_census_record.attributes = row.to_hash.slice(*ATTRIBUTES)
+      local_census_record
+    end
+
+    def empty_row?(row)
+      row.all? { |_, cell| cell.nil? }
+    end
+
+    def file_extension
+      return if valid_extension?
+
+      errors.add :file, :extension, valid_extensions: ALLOWED_FILE_EXTENSIONS.join(", ")
+    end
+
+    def fetch_file_headers
+      CSV.open(file.path, &:readline)
+    end
+
+    def file_headers_definition
+      headers = fetch_file_headers
+      return if headers.all? {|header| ATTRIBUTES.include? header } &&
+        ATTRIBUTES.all? {|attr| headers.include? attr }
+
+      errors.add :file, :headers, required_headers: ATTRIBUTES.join(", ")
+    end
+
+    def valid_extension?
+      ALLOWED_FILE_EXTENSIONS.include? extension
+    end
+
+    def extension
+      File.extname(file.original_filename).delete(".")
+    end
+end

config/locales/en/activemodel.yml

@@ -4,6 +4,9 @@ en:
       verification:
         residence: "Residence"
         sms: "SMS"
+      local_census_record/import:
+        one: Local census record import
+        other: Local census records imports
     attributes:
       verification:
         residence:
@@ -20,3 +23,12 @@ en:
         document_type: "Document type"
         document_number: "Document number (including letters)"
         year_of_birth: "Year born"
+      local_census_record/import:
+        file: File
+    errors:
+      models:
+        local_census_records/import:
+          attributes:
+            file:
+              extension: "Given file format is wrong. The allowed file format is: %{valid_extensions}."
+              headers: "Given file headers are wrong. The file headers must have the following names: %{required_headers}."

config/locales/es/activemodel.yml

@@ -4,6 +4,9 @@ es:
       verification:
         residence: "Residencia"
         sms: "SMS"
+      local_census_records/import:
+        one: Importación de registros del censo local
+        other: Importaciones de registros del censo local
     attributes:
       verification:
         residence:
@@ -20,3 +23,12 @@ es:
         document_type: "Tipo de documento"
         document_number: "Número de documento (incluida letra)"
         year_of_birth: "Año de nacimiento"
+      local_census_records/import:
+        file: Archivo
+    errors:
+      models:
+        local_census_records/import:
+          attributes:
+            file:
+              extension: "El formato del fichero es incorrecto. El formato de archivo permitido es: %{valid_extensions}."
+              headers: "Las cabeceras del fichero son incorrectas. Las cabeceras del fichero deben tener los nombres siguientes: %{required_headers}."

spec/factories/verifications.rb

@@ -5,6 +5,12 @@ FactoryBot.define do
     date_of_birth Date.new(1970, 1, 31)
     postal_code "28002"
   end
+  factory :local_census_records_import, class: "LocalCensusRecords::Import" do
+    file {
+      path = %w[spec fixtures files local_census_records import valid.csv]
+      Rack::Test::UploadedFile.new(Rails.root.join(*path))
+    }
+  end
 
   sequence(:document_number) { |n| "#{n.to_s.rjust(8, "0")}X" }
 

spec/fixtures/files/local_census_records/import/invalid.csv

@@ -0,0 +1,5 @@
+"document_type","document_number","date_of_birth","postal_code"
+,"44556678T","07/08/1984",7008
+"DNI",,"07/08/1985",7009
+"Passport","22556678T",,7010
+"NIE","X11556678","07/08/1987",

spec/fixtures/files/local_census_records/import/valid-without-headers.csv

@@ -0,0 +1,5 @@
+,,,
+"44556678T","DNI","07/08/84",7008
+"33556678T","DNI","07/08/84",7008
+"22556678T","DNI","07/08/84",7008
+"X11556678","NIE","07/08/84",7008

spec/fixtures/files/local_census_records/import/valid.csv

@@ -0,0 +1,5 @@
+"document_type","document_number","date_of_birth","postal_code"
+"DNI","44556678T","07/08/1984",7008
+"DNI","33556678T","07/08/1985",7008
+"DNI","22556678T","07/08/1986",7008
+"NIE","X11556678","07/08/1987",7008

spec/models/local_census_records/import_spec.rb

@@ -0,0 +1,88 @@
+require "rails_helper"
+
+describe LocalCensusRecords::Import do
+
+  let(:base_files_path) { %w[spec fixtures files local_census_records import] }
+  let(:import) { build(:local_census_records_import) }
+
+  describe "Validations" do
+    it "is valid" do
+      expect(import).to be_valid
+    end
+
+    it "is not valid without a file to import" do
+      import.file = nil
+
+      expect(import).not_to be_valid
+    end
+
+    context "When file extension" do
+      it "is wrong it should not be valid" do
+        file = Rack::Test::UploadedFile.new("spec/fixtures/files/clippy.gif")
+        import = build(:local_census_records_import, file: file)
+
+        expect(import).not_to be_valid
+      end
+
+      it "is csv it should be valid" do
+        path = base_files_path << "valid.csv"
+        file = Rack::Test::UploadedFile.new(Rails.root.join(*path))
+        import = build(:local_census_records_import, file: file)
+
+        expect(import).to be_valid
+      end
+    end
+
+    context "When file headers" do
+      it "are all missing it should not be valid" do
+        path = base_files_path << "valid-without-headers.csv"
+        file = Rack::Test::UploadedFile.new(Rails.root.join(*path))
+        import = build(:local_census_records_import, file: file)
+
+        expect(import).not_to be_valid
+      end
+    end
+  end
+
+  context "#save" do
+    it "Create valid local census records with provided values" do
+      import.save
+      local_census_record = LocalCensusRecord.find_by(document_number: "X11556678")
+
+      expect(local_census_record).not_to be_nil
+      expect(local_census_record.document_type).to eq("NIE")
+      expect(local_census_record.document_number).to eq("X11556678")
+      expect(local_census_record.date_of_birth).to eq(Date.parse("07/08/1987"))
+      expect(local_census_record.postal_code).to eq("7008")
+    end
+
+    it "Add successfully created local census records to created_records array" do
+      import.save
+
+      valid_document_numbers = ["44556678T", "33556678T", "22556678T", "X11556678"]
+      expect(import.created_records.collect(&:document_number)).to eq(valid_document_numbers)
+    end
+
+    it "Add invalid local census records to invalid_records array" do
+      path = base_files_path << "invalid.csv"
+      file = Rack::Test::UploadedFile.new(Rails.root.join(*path))
+      import.file = file
+
+      import.save
+
+      invalid_records_document_types = [nil, "DNI", "Passport", "NIE"]
+      invalid_records_document_numbers = ["44556678T", nil, "22556678T", "X11556678"]
+      invalid_records_date_of_births = [Date.parse("07/08/1984"), Date.parse("07/08/1985"), nil,
+        Date.parse("07/08/1987")]
+      invalid_records_postal_codes = ["7008", "7009", "7010", nil]
+      expect(import.invalid_records.collect(&:document_type))
+        .to eq(invalid_records_document_types)
+      expect(import.invalid_records.collect(&:document_number))
+        .to eq(invalid_records_document_numbers)
+      expect(import.invalid_records.collect(&:date_of_birth))
+        .to eq(invalid_records_date_of_births)
+      expect(import.invalid_records.collect(&:postal_code))
+      .to eq(invalid_records_postal_codes)
+    end
+  end
+end