From 9a4f4d782ba39cf15012628012db3f6f20bf714e Mon Sep 17 00:00:00 2001
From: Wirawan Purwanto <wirawan0@gmail.com>
Date: Thu, 16 Oct 2014 15:56:16 -0400
Subject: [PATCH] * Added first implementation (and test harness) for idatetime
   datatype.

---
 TESTS/test_datetime.py |  54 +++++++++++++++++++++
 datetime0_idt.py       | 103 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 157 insertions(+)
 create mode 100644 TESTS/test_datetime.py
 create mode 100644 datetime0_idt.py

diff --git a/TESTS/test_datetime.py b/TESTS/test_datetime.py
new file mode 100644
index 0000000..27d9dc2
--- /dev/null
+++ b/TESTS/test_datetime.py
@@ -0,0 +1,54 @@
+"""
+Test routines for wpylib.datetime module (and related submodules).
+"""
+
+from time import localtime, gmtime, strftime
+
+from wpylib.datetime0_idt import idatetime
+from wpylib.datetime import utime_to_iso
+
+
+
+def test_idt_01():
+  """[20141016]
+  Basic idatetime tests.
+  """
+  iidt = 20141201083724315
+  idt = idatetime(iidt)
+  print "integer value          = %+18d" % idt.idt
+  print "iso8601 format         = %s" % idt.str_iso8601()
+
+
+def test_u2i_01():
+  """[20141016]
+  Testing utime_to_iso subroutine.
+
+  Output:
+
+    unix time                           =  1413475094.058478
+    time interpretation (local)         =  Thu Oct 16 11:58:14 EDT 2014
+    utime_to_iso output (local)         =  2014-10-16 11:58:14 -04:00
+    utime_to_iso output (local/iso8601) =  2014-10-16T11:58:14.058478116-04:00
+    time interpretation (utc)           =  Thu Oct 16 15:58:14 EST 2014
+    utime_to_iso output (utc)           =  2014-10-16 15:58:14 +00:00
+    utime_to_iso output (utc/iso8601)   =  2014-10-16T15:58:14.058478116Z
+    utime_to_iso output (utc/idtstamp)  =  2014-10-16T15:58:14.058
+
+  """
+  unix_time = 1413475094.058478
+  str_time = utime_to_iso(unix_time, local=True)
+  str_gmtime = utime_to_iso(unix_time, local=False)
+  print "unix time                           = ", "%.16g" % unix_time
+
+  print "time interpretation (local)         = ", strftime("%a %b %e %H:%M:%S %Z %Y", localtime(unix_time))
+  print "utime_to_iso output (local)         = ", str_time
+  print "utime_to_iso output (local/iso8601) = ", utime_to_iso(unix_time, local=True, fmt='iso8601')
+
+  print "time interpretation (utc)           = ", strftime("%a %b %e %H:%M:%S %Z %Y", gmtime(unix_time))
+  print "utime_to_iso output (utc)           = ", str_gmtime
+  print "utime_to_iso output (utc/iso8601)   = ", utime_to_iso(unix_time, local=False, fmt='iso8601')
+  print "utime_to_iso output (utc/idtstamp)  = ", utime_to_iso(unix_time, local=False, fmt='idtstamp')
+
+
+
+
diff --git a/datetime0_idt.py b/datetime0_idt.py
new file mode 100644
index 0000000..73c417d
--- /dev/null
+++ b/datetime0_idt.py
@@ -0,0 +1,103 @@
+#
+# wpylib.datetime0_idt
+# Created: 20141015
+# Wirawan Purwanto
+#
+# Simple date/time stamp using 64-bit integer.
+# This module is an internal module; the exported name will
+# be put in wpylib.datetime module.
+#
+
+"""
+wplib.datetime0_idt module
+
+Simple date/time stamp using 64-bit integer.
+The primary motivation of creating this class is to store date/time
+information in the most compact way, while keeping the ease of
+human readability.
+
+The internal format is very simple:
+
+YYYYMMDDhhmmssfff
+
+where:
+ - YYYY = year (0 < YYYY <= 9999)
+ - MM   = month (1 <= MM <= 12)
+ - DD   = day
+ - hh   = hour (0 <= hh < 24)
+ - mm   = minutes
+ - ss   = seconds
+ - fff  = milliseconds
+
+The time is always expressed in terms of UTC to eliminate ambiguity of
+time zone, daylight savings time, etc.
+CAVEAT: The resolution of the time is only on the order of millisecond.
+
+This is a 17-decimal-digit integer, which fits in a 64-bit range (9.22e+18).
+
+"""
+
+from wpylib.params import struct
+
+
+class idatetime(object):
+  """Simple 8-byte integer representation of a date/time stamp.
+  """
+  def __init__(self, idt=None):
+    if idt != None:
+      self.idt = idt
+
+  def validate(self):
+    raise NotImplementedError
+
+  def split_values(self):
+    """Splits the compact datetime into components.
+    Warning: the values are NOT validated.
+    """
+    idt = self.idt
+    s = str(idt)
+    R = struct()
+    #R.YYYY, R.MM, R.DD, R.hh, R.mm, R.ss, R.fff # names are too cryptic
+    # Use same member names as in datetime (in sofar it is possible):
+    R.year, R.month, R.day, R.hour, R.minute, R.second, R.millisecond = map(int, [
+      s[:-13],    # year
+      s[-13:-11], # month
+      s[-11:-9],  # day
+      s[-9:-7],   # hour
+      s[-7:-5],   # min
+      s[-5:-3],   # sec
+      s[-3:]      # millisec
+    ])
+    R.microsecond = R.millisecond * 1000
+    return R
+
+  def to_datetime(self):
+    """Converts the object value to standard python datetime object.
+    """
+    from datetime import datetime
+    R = self.split_values()
+    dt = datetime(R.year, R.month, R.day, R.hour, R.minute, R.second, R.microsecond)
+    '''
+    idt = self.idt
+    s = str(idt)
+    YYYY, MM, DD, hh, mm, ss, ms = map(int, [
+      s[:-13],    # year
+      s[-13:-11], # month
+      s[-11:-9],  # day
+      s[-9:-7],   # hour
+      s[-7:-5],   # min
+      s[-5:-3],   # sec
+      s[-3:]      # millisec
+    ])
+    dt = datetime(YYYY, MM, DD, hh, mm, ss, fff*1000)
+    '''
+    return dt
+
+  def str_iso8601(self):
+    """Outputs the object according to ISO-8601 combined date/time format.
+    No time zone is shown."""
+    R = self.split_values()
+    fmt = "%(year)04d-%(month)02d-%(day)02dT%(hour)02d:%(minute)02d:%(second)02d.%(millisecond)03d"
+    return fmt % R
+
+