# frozen_string_literal: true

require 'eac_rails_utils/patches/active_model_associations'
require 'virtus'

module EacRailsUtils
  module Models
    class Tableless
      include ActiveModel::Model
      include Virtus.model
      include ActiveModel::Associations

      class << self
        def columns
          attribute_set.each.to_a
        end

        def columns_names
          columns.map(&:name)
        end
      end

      def initialize(values = {})
        super(build_attributes(values))
      end

      def attributes=(values)
        super(build_attributes(values))
      end

      # need hash like accessor, used internal Rails
      def [](attr)
        send(attr)
      end

      # need hash like accessor, used internal Rails
      def []=(attr, value)
        send("#{attr}=", value)
      end

      def save!
        save || raise("#{self.class}.save failed: #{errors.messages}")
      end

      private

      def build_attributes(values)
        AttributesBuilder.new(self.class, values).to_attributes
      end

      class AttributesBuilder
        DATE_TIME_FIELDS = %i[year month day hour min sec].freeze

        def initialize(model_class, values)
          @model_class = model_class
          @values = {}
          values.each { |k, v| add(k, v) }
        end

        def to_attributes
          @values
        end

        private

        def add(key, value)
          array_attr = parse_array_attr_key(key)
          if array_attr
            array_value_set(array_attr, value)
          else
            @values[key] = value
          end
        end

        def parse_array_attr_key(key)
          m = /\A(.+)\(([0-9]+)(.)\)\z/.match(key)
          return unless m

          ::OpenStruct.new(key: m[1], index: m[2].to_i - 1, converter: array_value_converter(m[3]))
        end

        def array_value_set(array_attr, value)
          @values[array_attr.key] ||= {}
          @values[array_attr.key].merge!(
            DATE_TIME_FIELDS[array_attr.index] => value.send(array_attr.converter)
          )
        end

        def array_value_converter(str_type)
          case str_type
          when 'i'
            'to_i'
          else
            raise "Unknown array type: \"#{str_type}\""
          end
        end

        def date_time_attribute?(key)
          attr = @model_class.attributes[key]
          return false unless attr

          raise attr.to_s
        end
      end
    end
  end
end