class Completion < ActiveRecord::Base
  belongs_to :task
  belongs_to :user

  def time_spent_text
    ChronicDuration.output time_spent
  end

  def time_spent_text= text
    self.time_spent = ChronicDuration.parse text
    logger.debug "time_spent: '#{self.time_spent_text}' for text '#{text}'"
  end

end

class DurationType < ActiveRecord::Type::String
  def cast(value)
    return value if value.blank? || value.is_a?(ActiveSupport::Duration)

    ActiveSupport::Duration.parse(value)
  end

  def serialize(duration)
    duration ? duration.iso8601 : nil
  end
end

ActiveRecord::Type.register(:duration, DurationType)

create_table :somethings do |t|
  t.duration :string
end

class Something < ApplicationRecord
  attribute :duration, :duration
end

something = Something.new
something.duration = 1.year    # 1 year
something.duration = nil
something.duration = "P2M3D"   # 2 months, 3 days (ISO8601 string)
Time.now + something.duration  # calculation is always correct