module Ecom
  module Core
    class TakeoffCalculator < ApplicationRecord
      INPUT_PARAMETERS_SCHEMA = {
        'type' => 'object',
        'required' => %w[name label input_type],
        'additionalProperties' => false,
        'properties' => {
          'name' => { 'type' => 'string' },
          'label' => { 'type' => 'string' },
          'input_type' => {
            'type' => 'string',
            'enum' => %w[string number measurement enum]
          }
        },
        "patternProperties": {
          "enum_values": {
            'type' => 'array'
          },
          "default_value": {
            'type' => 'object',
            'required' => %w[value],
            'properties' => {
              'value' => { 'type' => 'string' }
            },
            "patternProperties": {
              "measurement_unit_id": { 'type' => 'integer' }
            }
          },
          "validation": {
            'type' => 'object',
            'required' => %w[required],
            'properties' => {
              'required' => { 'type' => 'boolean' }
            },
            "patternProperties": {
              "minimum": { 'type' => 'number' },
              "maximum": { 'type' => 'number' }
            }
          }
        }
      }.freeze

      REBAR_TAKEOFF_CALCULATOR = 'Rebar Takeoff Calculator'.freeze
      FORMWORK_TAKEOFF_CALCULATOR = 'Formwork Takeoff Calculator'.freeze
      CONCRETE_POURING_TAKEOFF_CALCULATOR =
        'Concrete Pouring Takeoff Calculator'.freeze

      TAKEOFF_CALCULATOR_NAMES =
        [
          REBAR_TAKEOFF_CALCULATOR,
          FORMWORK_TAKEOFF_CALCULATOR,
          CONCRETE_POURING_TAKEOFF_CALCULATOR
        ].freeze

      validates :name, :input_parameters, presence: true
      validates :name, inclusion: TAKEOFF_CALCULATOR_NAMES

      validates :name, uniqueness: true

      validate :input_parameters_schema
      validate :measurement_unit_id_in_input_parameters
      validate :enum_in_input_parameters

      def input_parameters_schema
        return if input_parameters.nil?

        errors.add(:input_parameters, 'There has to be one or more input parameters') if input_parameters.count.zero?

        validation_errors = JSON::Validator.fully_validate(INPUT_PARAMETERS_SCHEMA,
                                                           input_parameters, strict: true,
                                                                             list: true, clear_cache: true)

        errors.add(:input_parameters, validation_errors) unless validation_errors.empty?
      end

      def measurement_unit_id_in_input_parameters
        return if input_parameters.nil?

        input_parameters.each do |input_parameter|
          next unless input_parameter['input_type'] == 'measurement' && !input_parameter['default_value'].nil?

          if input_parameter['default_value']['measurement_unit_id'].nil?
            errors.add(:base, 'measurement_unit_id is required')
            next
          end

          measurement_unit_id = input_parameter['default_value']['measurement_unit_id']
          measurement_unit = Ecom::Core::MeasurementUnit.find_by(id: measurement_unit_id)

          errors.add(:base, "measurement unit with id #{measurement_unit_id} does not exist") if measurement_unit.nil?
        end
      end

      def enum_in_input_parameters
        return if input_parameters.nil?

        input_parameters.each do |input_parameter|
          next if input_parameter['input_type'] != 'enum'

          if input_parameter['enum_values'].nil?
            errors.add(:base, 'enum_values are requiered if the input_type is enum')
            next
          end

          next unless !input_parameter['enum_values'].nil? &&
                      input_parameter['enum_values'].class == Array &&
                      input_parameter['enum_values'].count.zero?

          errors.add(:base, 'Provide at least one enum value')
        end
      end
    end
  end
end