require 'date.rb'

class SwedishSocialSecurityNumber
    attr_reader :socialSecurityNumber, :year, :month, :day, :code, :isOver100

    def initialize(socialSecurityNumber)
        @socialSecurityNumber = socialSecurityNumber
        raise ArgumentError, "The format has to be YYMMDD-XXXX or YYMMDD+XXXX" unless right_pattern?

        @isOver100 = false;
        @year = @socialSecurityNumber[0,2].to_i
        @month = @socialSecurityNumber[2,2].to_i
        @day = @socialSecurityNumber[4,2].to_i
        @isOver100 = true if @socialSecurityNumber[6,1] == "+"
        @code = @socialSecurityNumber[7,4].to_i

        raise ArgumentError, "The date is invalid or fictional" unless date_valid?
        raise ArgumentError, "The control number is invalid" unless check_sum == @socialSecurityNumber[10,1].to_i
    end

    def check_sum
        variegated = 2;
        temp = 0;
        list = Array.new

        0.upto(@socialSecurityNumber.length - 2) { |position|
            next if position == 6
            temp = @socialSecurityNumber[position].to_i
            temp = temp * variegated
            temp.to_s.split("").each { |c|
                list.push(c.to_i)
            }

            variegated = variegated == 2 ? 1 : 2
        }

        sum = 0
        list.each { |i|
            sum = sum + i
        }

        return (10 - (sum % 10))
    end

    def full_year
        current_year = Time.new.year
        temp_str = ""
        if @year < 10
            temp_str = current_year.to_s[0,2] + "0" + @year.to_s
        else
            temp_str = current_year.to_s[0,2] + @year.to_s
        end

        return temp_str.to_i - 100 if @isOver100
        return temp_str.to_i - 100 if temp_str.to_i > @year

        return temp_str.to_i
    end

    def female?
        (@socialSecurityNumber[9,1].to_i % 2) == 0
    end

    def male?
        !female?
    end

    private
    def right_pattern?
        !/^[0-9]{2}[0-1][0-9][0-3][0-9][-|+][0-9]{4}$/.match(@socialSecurityNumber).nil?
    end

    def date_valid?
        d = nil
        begin
            d = Date.new(full_year, @month, @day)
        rescue
            return false
        end

        current_date = Time.new
        return false if d > current_date.to_date
        true
    end
end