require 'date'

module OpenEHR
  module Assumed_Library_Types
    class Any < Object
      
    end # of Any
    class Interval < Any
      attr_reader :lower, :lower_included, :lower_unbounded
      attr_reader :upper, :upper_included, :upper_unbounded
      def initialize(lower, upper, 
                     lower_included = nil, upper_included = nil)
        check_lower_upper(lower, upper)
        set_lower_included(lower_included)
        set_upper_included(upper_included)
      end

      def set_lower(lower)
        check_lower_upper(lower, @upper)
      end

      def set_upper(upper)
        check_lower_upper(@lower, upper)
      end

      def set_lower_included(lower_included)
        if (lower == nil) && (lower_included != nil)
          raise ArgumentError, "lower is not set"
        end
        @lower_included = lower_included
      end

      def set_upper_included(upper_included)
        @upper_included = upper_included
        if (upper == nil) && (upper_included != nil)
          raise ArgumentError, "upper is not set"
        end
      end

      def has?(value)
        if ((@lower < value) && (value < @upper) ||
            (@lower_included == true) && (@lower == value) ||
            (@upper_included == true) && (@upper == value))
          true
        else
          false
        end
      end

      private

      def check_lower_upper(lower, upper)
        if (lower == nil) && (upper == nil)
          raise ArgumentError, "Either lower or upper must be assigned"
        end
        if (lower == nil) && (upper != nil)
          @lower_unbounded = true          
        elsif (lower != nil) && (upper == nil)
          @upper_unbounded = true
        elsif lower > upper
          raise ArgumentError, "Upper must be larger than lower."
        end
        @lower = lower
        @upper = upper
      end      
    end # end of Interval

    class TIME_DEFINITIONS < Any
      DAYS_IN_LEAP_YEAR = 366
      DAYS_IN_WEEK = 7
      DAYS_IN_YEAR = 365
      HOURS_IN_DAY = 24
      MAX_DAYS_IN_MONTH = 31
      MAX_DAYS_IN_YEAR = 366
      MINUTES_IN_HOUR = 60
      MONTH_IN_YEAR = 12
      NOMINAL_DAYS_IN_MONTH = 30.42
      NOMINAL_DAYS_IN_YEAR = 365.24
      SECONDS_IN_MINUTE = 60

      def self.valid_year?(year)
        year >= 0
      end

      def self.valid_day?(y, m, d)
        Date.valid_date?(y,m,d) and valid_year? y
      end

      def self.valid_hour?(h,m,s)
        valid_minute?(m) and valid_second?(s) and ((h >= 0 and h < HOURS_IN_DAY) or (h == HOURS_IN_DAY and m == 0 and s == 0))
      end
      def self.valid_minute?(m)
        m >= 0 and m < MINUTES_IN_HOUR
      end
      def self.valid_second?(s)
        s >= 0 and s < SECONDS_IN_MINUTE
      end
      def self.valid_month?(m)
        m >= 1 and m <= MONTH_IN_YEAR
      end
    end # end of TIME_DEFINITIONS

    class ISO8601_DATE < TIME_DEFINITIONS
      attr_reader :year, :month, :day
      def initialize(year = nil, month = nil, day = nil)
        @year = @month = @day = nil
        if !year.nil?
          self.year = year
        end
        if !month.nil?
          self.month = month
        end
        if !day.nil?
          self.day = day
        end
      end
      def year=(year)
        raise ArgumentError, "Year is not valid" if !ISO8601_DATE.valid_year?(year)
        @year = year
      end
      def month=(month)
        raise ArgumentError, "Month is not valid" if !ISO8601_DATE.valid_month?(month)
        @month = month
      end
      def day=(day)
        raise ArgumentError, "Day is not valid" if !ISO8601_DATE.valid_day?(@year, @month, day)
        @day = day
      end
      def as_string
        if (!@year.nil? and !@month.nil? and !@day.nil?)
          Date.new(@year, @month, @day).to_s
        elsif (!@year.nil? and !@month.nil? and @day.nil?)
          Date.new(@year, @month).to_s[0,7]
        elsif (!@year.nil? and @month.nil? and @day.nil?)
          Date.new(@year).to_s[0,4]
        end          
      end
      def month_unknown?
        @month.nil?
      end
      def day_unknown?
        @day.nil?
      end
      def is_extended?
        true
      end
      def is_partial?
        month_unknown? or day_unknown?
      end
      def valid_iso8601_date(string)
        begin
          date = Date.parse(string)
        rescue
          return false
        end
        true
      end
    end # end of ISO8601_DATE

    class ISO8601_TIME < TIME_DEFINITIONS

    end # end of ISO8601_TIME

    class ISO8601_TIMEZONE
      attr_accessor :sign, :hour, :minute
      def is_gmt?
        hour == 0
      end
      def as_string
        sprintf("Z%s%2d%2d", @sign, @hour, @minute)
      end
    end # end of ISO8601_TIMEZONE
  end # end of Assumed_Types
end # end of OpenEHR