contact_storage_worker.rb

# frozen_string_literal: true

class ContactStorageWorker
  include Sidekiq::Worker
  sidekiq_options retry: false

  attr_accessor :user_id, :contact_params

  def perform(contact_params, user_id)
    @user_id = user_id
    @contact_params = contact_params
    ActiveRecord::Base.connection.exec_query(insertion_query)
  end

  private

  ## build a bulk insert query. see https://adevelopersdiary.com/bulk-insert-data-in-a-table-through-ruby-on-rails/
  def insertion_query
    invalid_starts = %w[0 1 2 3 4 5] # mobile numbers start with 6, 7, 8, or 9 only.
    query = contact_params.map do |contact|
      number = parse_integers(contact['phone_number'])
      next if number.to_s.length != 10 # mobile numbers must be of 10 digits.
      next if number.to_s.starts_with?(*invalid_starts)

      "('#{remove_special_chars(contact['name'])}',
        '#{number}',
         #{user_id})"
    end.compact.join(', ')
    return unless query.present? # do not proceed if no valid mobile numbers found.

    # insert data in contacts
    <<-QUERY
      INSERT INTO contacts (name, phone_number, user_id)
      VALUES #{query}
      ON CONFLICT (user_id, phone_number) WHERE user_id > 0 -- uniqueness contraint.
        DO NOTHING;
    QUERY
  end

  def remove_special_chars(string_literal)
    string_literal.to_s.gsub(/[^0-9 A-Za-z]/, ' ').strip
  end

  def parse_integers(string_literal)
    string_literal.to_s.gsub(/[^0-9]/, '').chars.last(10).join
  end
end


## specs

# frozen_string_literal: true

require 'rails_helper'

describe ContactStorageWorker do
  let!(:user) { create(:user) }

  it 'Stores the contacts, while sanitizing the values for name and number' do
    Sidekiq::Testing.inline!
    params = [{ name: 'a', phone_number: 923_456_789 }, ## will be rejected because length is less than 10
              { name: 'b', phone_number: 9_234_567_890 },
              { name: 'c', phone_number: 9_234_567_899 },
              { name: 'd', phone_number: 92_345_678_992 }, # ignored, because last 10 digits start with 2
              { name: 'e', phone_number: 9_234_567_893 },
              { name: 'e2', phone_number: '0234567893' }, ## will be rejected because starts with 0
              { name: 'e2', phone_number: 1_234_567_893 }, ## will be rejected because starts with 1
              { name: 'e2', phone_number: 2_234_567_893 }, ## will be rejected because starts with 2
              { name: 'e2', phone_number: 3_234_567_893 }, ## will be rejected because starts with 3
              { name: 'e2', phone_number: 4_234_567_893 }, ## will be rejected because starts with 4
              { name: 'e2', phone_number: 5_234_567_893 }, ## will be rejected because starts with 5
              { name: 'e2', phone_number: 923_456_789 }, ## will be rejected because length is less than 10
              { name: '', phone_number: 9_234_567_899 }, # will be rejected due to no name
              { name: 'g', phone_number: 92_345_678 }] ## will be rejected because length is less than 10

    ContactStorageWorker.perform_async(params, user.id)
    expect(user.contacts.count).to eq(3)
  end

  it "Doesn't do anything on number conflict" do
    contacts = [{ name: 'a', phone_number: 923_456_789 }, ## will be rejected because length is less than 10
                { name: 'b', phone_number: 9_234_567_890 },
                { name: 'c', phone_number: 9_234_567_899 },
                { name: 'd', phone_number: 92_345_678_992 },
                { name: 'e', phone_number: 9_234_567_893 },
                { name: 'f', phone_number: 92_345_678 }]
    user.contacts.create(contacts)

    params = [{ name: 'g', phone_number: 923_456_789 }, # already as 'a'
              { name: 'h', phone_number: 9_234_567_890 },   # already as 'b'
              { name: 'i', phone_number: 9_234_567_899 },   # already as 'c'
              { name: 'k', phone_number: 9_234_567_893 },   # already as 'e'
              { name: 'l', phone_number: 92_999_678_999_292 }, # will be the new entry
              { name: 'm', phone_number: 92_345_678 }, # already as f
              { name: '_.$#!@%^&*(  n  ){}[', phone_number: 129_874_561_230 }] # new entry, as n, will take last 10 digits only

    Sidekiq::Testing.inline!
    ContactStorageWorker.perform_async(params, user.id)
    # expect(user.contacts.count).to eq(6)
    expect(user.contacts.pluck(:name)).to contain_exactly('a', 'b', 'c', 'd', 'e', 'f', 'l', 'n')
  end
end