old-roraccounting/app/models/money_move.rb

class MoneyMove < ApplicationRecord
  belongs_to :homie

  def self.create_move(params)
    return false unless valid_money_move?(params)

    move_from = create_move_from(params) if double_money_move?(params)
    move_to = create_move_to(params)

    MoneyMove.transaction do
      move_from.save! if move_from.present?
      move_to.save!
    end
  end

  class << self
    private

    def valid_money_move?(params)
      params[:amount].present? && params[:to_homie_id].present?
    end

    def double_money_move?(params)
      params[:from_homie_id].present? && params[:to_homie_id].present?
    end

    def from_source_name(params)
      if double_money_move?(params)
        Homie.find(params[:from_homie_id]).name
      else
        'External'
      end
    end

    def create_move_from(params)
      to_homie_name = Homie.find(params[:to_homie_id]).name
      new_desc = "[#{to_homie_name}] #{params[:description]}".lstrip
      MoneyMove.new(
        homie_id: params[:from_homie_id],
        amount: -params[:amount].to_d,
        description: new_desc
      )
    end

    def create_move_to(params)
      new_desc = "[#{from_source_name(params)}] #{params[:description]}".lstrip
      MoneyMove.new(
        homie_id: params[:to_homie_id],
        amount: params[:amount].to_d,
        description: new_desc
      )
    end
  end
end