#!/usr/bin/env python
# -----------------------------------------------------------------------
# Copyright (C) 2004 Dan Fritz.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of MER-
# CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details.
# -----------------------------------------------------------------------
#
# This is a testcase generator for the timezone.py file.
# It finds daylight saving transition times, and outputs them as an unittest case
#
# Usage:
# TZ='<tz>' python timezone_test_gen.py <testcase number> <tz>
#
# where <tz> is the timezone you want to generate tests for: Australia/Sydney
# and <testcase number> is the number you want your testcase to start at.
#
# -----------------------------------------------------------------------
# Subversion Information, do not edit
#
# $Rev: $
# $LastChangedDate: $
# $LastChangedRevision: $
# $LastChangedBy: $
#
# $Log: $
#

from datetime import datetime, timedelta
import time
import sys
from tvgrab.datetime2 import DateTime, Date, Time, now
from copy import copy
import re

def toUtcOffset(sec):
  # altzone has DST included
  offset = time.altzone + 3600
  if sec.t[8]:
    offset -= 3600
  az = abs(offset) # altzone
  rv = str(az/3600) + ":"
  az = az % 3600
  rv += str(az/60).zfill(2) + ":"
  az = az % 60
  rv += str(az).zfill(2)
  if offset > 0:
    # Lol, this is funny. altzone is positive if utcoffset is negative.
    # A bit US centric, are we?
    rv = "-" + rv
  return rv
  
def findTransition(from_dt, to_dt):
  if from_dt.t[8] == to_dt.t[8]:
    return None
    
  diff = to_dt - from_dt
  index_dt = copy(from_dt).addSeconds(diff/2.0)
  
  while diff > 1 :
    if index_dt.t[8] == from_dt.t[8]:
      from_dt = index_dt
    else:
      to_dt = index_dt
      
    diff = to_dt - from_dt
    index_dt = copy(from_dt).addSeconds(diff/2.0)
  if from_dt.t[8] != to_dt.t[8]:
    return from_dt
  else:
    return None
    
if __name__ == '__main__':

  print "utcOffset = " + toUtcOffset(now())
  from_dt = DateTime(Date("2000-01-01"), Time("01:00:00"))
  to_dt = DateTime(Date("2025-01-01"), Time("01:00:00"))
  remove_silly_octal_mode = re.compile(",0(\d)")
  
  testNumber = int(sys.argv[1])
  tzName = sys.argv[2]
  
  while from_dt < to_dt:
    tran_dt = findTransition(copy(from_dt), copy(from_dt).addHours(24*7))
    if tran_dt:
      #generate the testcase
      tc = "  def test" + str(testNumber).zfill(3) + "(self): self.vt("
      tran_dt.output_fmt = "d(%Y,%m,%d,%H,%M,%S)"
      tc += str(tran_dt)
      tc += ",'" + tzName + "',('"
      tc += toUtcOffset(tran_dt) + "','" + toUtcOffset(tran_dt.addSeconds(1))
      tc += "'))"
      tc = remove_silly_octal_mode.sub(", \g<1>", tc)
      print tc
      testNumber += 1
    from_dt.addHours(24*7)