# date, dateTime methods
# for ADIwg readers and writers

# History:
# 	Stan Smith 2013-09-26 original script
# 	Stan Smith 2013-12-06 added support for fractional seconds

require 'date'

module AdiwgDateTimeFun

    def self.dateTimeFromString(inDateTime)
        hFormats = {'YMDhmsLZ' => '%Y-%m-%dT%H:%M:%S.%L%z',
                    'YMDhmsL' => '%Y-%m-%dT%H:%M:%S.%L',
                    'YMDhmsZ' => '%Y-%m-%dT%H:%M:%S%z',
                    'YMDhms' => '%Y-%m-%dT%H:%M:%S',
                    'YMDhmZ' => '%Y-%m-%dT%H:%M%z',
                    'YMDhm' => '%Y-%m-%dT%H:%M',
                    'YMDhZ' => '%Y-%m-%dT%H%z',
                    'YMDh' => '%Y-%m-%dT%H',
                    'YMD' => '%Y-%m-%d',
                    'YM' => '%Y-%m',
                    'Y' => '%Y'}
        hFormats.each do |dateResolution, format|
            myDateTime = DateTime.strptime(inDateTime, format) rescue false
            return myDateTime, dateResolution if myDateTime
        end

        return nil, 'ERROR'
    end

    def self.stringDateFromDateTime(myDateTime, dateResolution)
        s = case dateResolution
                when 'YMDhmsLZ', 'YMDhmsL', 'YMDhmsZ', 'YMDhms',
                    'YMDhmZ', 'YMDhm', 'YMDhZ', 'YMDh', 'YMD'
                    myDateTime.strftime('%Y-%m-%d')
                when 'YM'
                    myDateTime.strftime('%Y-%m')
                when 'Y'
                    myDateTime.strftime('%Y')
                else
                    'ERROR'
            end

        return s
    end

    def self.stringDateTimeFromDateTime(myDateTime, dateResolution)
        s = case dateResolution
                when 'YMDhmsLZ'
                    myDateTime.strftime('%Y-%m-%dT%H:%M:%S.%L%:z')
                when 'YMDhmsL'
                    myDateTime.strftime('%Y-%m-%dT%H:%M:%S.%L')
                when 'YMDhmsZ'
                    myDateTime.strftime('%Y-%m-%dT%H:%M:%S%:z')
                when 'YMDhms', 'YMD', 'YM', 'Y'
                    myDateTime.strftime('%Y-%m-%dT%H:%M:%S')
                when 'YMDhmZ'
                    myDateTime.strftime('%Y-%m-%dT%H:%M%:z')
                when 'YMDhm'
                    myDateTime.strftime('%Y-%m-%dT%H:%M')
                when 'YMDhZ'
                    myDateTime.strftime('%Y-%m-%dT%H%:z')
                when 'YMDh'
                    myDateTime.strftime('%Y-%m-%dT%H')
                else
                    'ERROR'
            end

        return s
    end

    def self.stringTimeFromDateTime(myDateTime, dateResolution)
        s = case dateResolution
                when 'YMDhmsLZ'
                    myDateTime.strftime('%H:%M:%S.%L%:z')
                when 'YMDhmsL'
                    myDateTime.strftime('%H:%M:%S.%L')
                when 'YMDhmsZ'
                    myDateTime.strftime('%H:%M:%S%:z')
                when 'YMDhms'
                    myDateTime.strftime('%H:%M:%S')
                when 'YMDhmZ'
                    myDateTime.strftime('%H:%M%:z')
                when 'YMDhm'
                    myDateTime.strftime('%H:%M')
                when 'YMDhZ'
                    myDateTime.strftime('%H%:z')
                when 'YMDh'
                    myDateTime.strftime('%H')
                else
                    'ERROR'
            end

        return s
    end

end