#--
# Copyright (c) 2005-2006 Philip Ross
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
#++
require 'tzinfo/offset_rationals'
require 'tzinfo/time_or_datetime'
module TZInfo
# A period of time in a timezone where the same offset from UTC applies.
#
# All the methods that take times accept instances of Time, DateTime or
# integer timestamps.
class TimezonePeriod
# The TimezoneTransitionInfo that defines the start of this TimezonePeriod
# (may be nil if unbounded).
attr_reader :start_transition
# The TimezoneTransitionInfo that defines the end of this TimezonePeriod
# (may be nil if unbounded).
attr_reader :end_transition
# The TimezoneOffsetInfo for this period.
attr_reader :offset
# Initializes a new TimezonePeriod.
def initialize(start_transition, end_transition, offset = nil)
@start_transition = start_transition
@end_transition = end_transition
if offset
raise ArgumentError, 'Offset specified with transitions' if @start_transition || @end_transition
@offset = offset
else
if @start_transition
@offset = @start_transition.offset
elsif @end_transition
@offset = @end_transition.previous_offset
else
raise ArgumentError, 'No offset specified and no transitions to determine it from'
end
end
@utc_total_offset_rational = nil
end
# Base offset of the timezone from UTC (seconds).
def utc_offset
@offset.utc_offset
end
# Offset from the local time where daylight savings is in effect (seconds).
# E.g.: utc_offset could be -5 hours. Normally, std_offset would be 0.
# During daylight savings, std_offset would typically become +1 hours.
def std_offset
@offset.std_offset
end
# The identifier of this period, e.g. "GMT" (Greenwich Mean Time) or "BST"
# (British Summer Time) for "Europe/London". The returned identifier is a
# symbol.
def abbreviation
@offset.abbreviation
end
alias :zone_identifier :abbreviation
# Total offset from UTC (seconds). Equal to utc_offset + std_offset.
def utc_total_offset
@offset.utc_total_offset
end
# Total offset from UTC (days). Result is a Rational.
def utc_total_offset_rational
unless @utc_total_offset_rational
@utc_total_offset_rational = OffsetRationals.rational_for_offset(utc_total_offset)
end
@utc_total_offset_rational
end
# The start time of the period in UTC as a DateTime. May be nil if unbounded.
def utc_start
@start_transition ? @start_transition.at.to_datetime : nil
end
# The end time of the period in UTC as a DateTime. May be nil if unbounded.
def utc_end
@end_transition ? @end_transition.at.to_datetime : nil
end
# The start time of the period in local time as a DateTime. May be nil if
# unbounded.
def local_start
@start_transition ? @start_transition.local_start.to_datetime : nil
end
# The end time of the period in local time as a DateTime. May be nil if
# unbounded.
def local_end
@end_transition ? @end_transition.local_end.to_datetime : nil
end
# true if daylight savings is in effect for this period; otherwise false.
def dst?
@offset.dst?
end
# true if this period is valid for the given UTC DateTime; otherwise false.
def valid_for_utc?(utc)
utc_after_start?(utc) && utc_before_end?(utc)
end
# true if the given UTC DateTime is after the start of the period
# (inclusive); otherwise false.
def utc_after_start?(utc)
!@start_transition || @start_transition.at <= utc
end
# true if the given UTC DateTime is before the end of the period
# (exclusive); otherwise false.
def utc_before_end?(utc)
!@end_transition || @end_transition.at > utc
end
# true if this period is valid for the given local DateTime; otherwise false.
def valid_for_local?(local)
local_after_start?(local) && local_before_end?(local)
end
# true if the given local DateTime is after the start of the period
# (inclusive); otherwise false.
def local_after_start?(local)
!@start_transition || @start_transition.local_start <= local
end
# true if the given local DateTime is before the end of the period
# (exclusive); otherwise false.
def local_before_end?(local)
!@end_transition || @end_transition.local_end > local
end
# Converts a UTC DateTime to local time based on the offset of this period.
def to_local(utc)
@offset.to_local(utc)
end
# Converts a local DateTime to UTC based on the offset of this period.
def to_utc(local)
@offset.to_utc(local)
end
# Returns true if this TimezonePeriod is equal to p. This compares the
# start_transition, end_transition and offset using ==.
def ==(p)
p.respond_to?(:start_transition) && p.respond_to?(:end_transition) &&
p.respond_to?(:offset) && start_transition == p.start_transition &&
end_transition == p.end_transition && offset == p.offset
end
# Returns true if this TimezonePeriods is equal to p. This compares the
# start_transition, end_transition and offset using eql?
def eql?(p)
p.respond_to?(:start_transition) && p.respond_to?(:end_transition) &&
p.respond_to?(:offset) && start_transition.eql?(p.start_transition) &&
end_transition.eql?(p.end_transition) && offset.eql?(p.offset)
end
# Returns a hash of this TimezonePeriod.
def hash
result = @start_transition.hash ^ @end_transition.hash
result ^= @offset.hash unless @start_transition || @end_transition
result
end
# Returns internal object state as a programmer-readable string.
def inspect
result = "#<#{self.class}: #{@start_transition.inspect},#{@end_transition.inspect}"
result << ",#{@offset.inspect}>" unless @start_transition || @end_transition
result + '>'
end
end
end