module Identification
  # Represents an identity document.
  # This class carries base methods that will appear in all document types.
  #
  # @abstract Subclass and implement a {#parse} method (setting the fields and @validity)
  # and alter {#initialize} to implement a custom Document class. See other classes for examples.
  class Document
    attr_accessor :last_name, :date_of_birth, :gender

    # Creates an instance of a documents.
    # Will automatically parse if the drivers number is given, and will automatically generate if all necessary fields are set.
    #
    # @param [Hash] details of the paramaters
    # @option opts [String] :last_name surname of the individual (only set for generating)
    # @option opts [String] :date_of_birth date of birth of the individual (only set for generating)
    # @option opts [String] :gender gender of the individual (only set for generating)
    def initialize(params = {})
      @last_name = params[:last_name]
      @date_of_birth = params[:date_of_birth]
      @gender = params[:gender]
    end

    # Returns true if the drivers license is valid.
    # Requires the driver number to be parsed before it can be called.
    #
    # @return [Boolean] whether or not the passport is valid
    # @raise [RuntimeError] if no mrz has been parsed yet.
    def valid?
      if defined? @validity
        return @validity
      else
        fail 'No document number has been parsed.'
      end
    end

    # Returns the age of the individual.
    # Requires a date of birth to be set before it can be called.
    #
    # @return [Boolean] age of the individual
    # @raise [RuntimeError] if no date of birth is set
    def age
      if !@date_of_birth.nil?
        now = Time.now.utc.to_date
        dob = @date_of_birth
        return now.year - dob.year - ((now.month > dob.month || (now.month == dob.month && now.day >= dob.day)) ? 0 : 1)
      else
        fail 'No date of birth has been set.'
      end
    end

    # Returns true if the individual is over 18 (18+)
    # Requires a date of birth to be set before it can be called.
    #
    # @return [Boolean] whether or not the individual is over 18
    # @raise [RuntimeError] if no date of birth is set
    def over_18?
      if !@date_of_birth.nil?
        return true if age >= 18
      else
        fail 'No date of birth has been set.'
      end

      false
    end

    # Returns true if the individual is over 21 (21+)
    # Requires a date of birth to be set before it can be called.
    #
    # @return [Boolean] whether or not the individual is over 21
    # @raise [RuntimeError] if no date of birth is set
    def over_21?
      if !@date_of_birth.nil?
        return true if age >= 21
      else
        fail 'No date of birth has been set.'
      end

      false
    end
  end
end