cprussin/formatted-date

require 'date'

module FormattedDate

    # This module contains instance extensions for the `Time` and `DateTime`
    # classes.
    module TimeInstanceMethods

        # Returns the word _Today_, _Tomorrow_, or _Yesterday_ as appropriate
        # relative to the passed date.
        #
        # @param date [Date] the date to compare this object with
        # @return [String] _Today_, _Tomorrow_, _Yesterday_, or `nil`
        def date_alternative(date = Date.today)
            to_date.alternative(date)
        end

        # Returns the word _Midnight_ or _Noon_ as appropriate for this time.
        #
        # @return [String] _Midnight_, _Noon_, or `nil`
        def time_alternative
            if hour == 0 && min == 0 && sec == 0
                'Midnight'
            elsif hour == 12 && min == 0 && sec == 0
                'Noon'
            end
        end

        # If the method called was one of the keys in the `formats` hash, then this
        # will return the time object formatted appropriately.  If a `Date` is
        # passed, then it will be used as the reference date whenever calling
        # `date_alternative`.
        #
        # @param method [Symbol] the name of the called method
        # @param args [Array] the arguments passed
        # @return [String] the formatted date, if the called method was a format
        # @raise [NoMethodError] if the called method was not a format
        def method_missing(method, *args)
            if self.class.formats.has_key?(method)
                format = self.class.formats[method]
                alt = format[:alternatives]
                str = []
                if format.has_key?(:date)
                    str << (if alt.nil? || [true, :date].include?(alt)
                        args.empty? ? date_alternative : date_alternative(args.first)
                    end || strftime(format[:date]))
                end
                str << format[:glue] if format.has_key?(:glue)
                if format.has_key?(:time)
                    str << (if alt.nil? || [true, :time].include?(alt)
                        time_alternative
                    end || strftime(format[:time]))
                end
                str.join(' ')
            else
                super
            end
        end
    end

    # This module contains class extensions for the `Time` and `DateTime`
    # classes.
    module TimeClassMethods

        # This hash lists recognized formats for time classes.  The keys are the
        # symbol names of the formats.  The values are hashes with the following
        # keys (note that each key is optional and if left out, the corresponding
        # section will be hidden from formatted output):
        #
        # - **date**: the `strftime` format for the date part
        # - **time**: the `strftime` format for the time part
        # - **glue**: text to put between between the date and time parts (e.g.
        #   'on'), surrounding spaces added automatically
        # - **alternatives**: `false` to suppress using alternatives like _Today_,
        #   _Midnight_, or _Noon_, `:date` to only use date alternatives, and
        #   `:time` to only use time alternatives
        attr_accessor :formats
    end

    DateTime.include(TimeInstanceMethods)
    DateTime.extend(TimeClassMethods)
    Time.include(TimeInstanceMethods)
    Time.extend(TimeClassMethods)
end