add leap second announcement monitor

Signed-off-by: Mattias Andrée <maandree@operamail.com>

3 files changed, 202 insertions, 2 deletions

diff --git a/TODO b/TODO
index 0e6b0ba..8286919 100644
--- a/TODO
+++ b/TODO
@@ -27,8 +27,6 @@ List of plugins to implement:
      Identify active and visible windows
      Calendars: holidays, birthdays, name days, events
      Clock plugin with timezone support
-     Leap second announcement (should work (but tell) if the system does
-         not observe leap seconds or uses smear seconds)
      Summer time / standard time announcement (should support double
          summer time and similar)
      natural disaster reports
diff --git a/examples/plugins/leapsec b/examples/plugins/leapsec
new file mode 100644
index 0000000..db70870
--- /dev/null
+++ b/examples/plugins/leapsec
@@ -0,0 +1,68 @@
+# -*- python -*-
+
+# A xpybar configuration example testing the features of plugins.leapsec
+
+import time
+import threading
+
+from plugins.leapsec import LeapSeconds
+from plugins.clock import Clock
+
+
+OUTPUT, HEIGHT, YPOS, TOP = 0, 12, 24, True
+
+
+clock = Clock(sync_to = 0.5 * Clock.SECONDS)
+
+start_ = start
+def start():
+    start_()
+    async(lambda : clock.continuous_sync(lambda : bar.invalidate()))
+
+
+leapsec_ = Sometimes(LeapSeconds, 30 * 24 * 60 * 2)
+
+
+def redraw():
+    announcements = leapsec_()
+    found = -1
+    now = time.time()
+    for index in range(len(announcements)):
+        if announcements[index][3] >= now:
+            found = index
+            break
+    announcement = announcements[found]
+    text = '\033[%sm%s\033[00m ago' if found < 0 else 'in \033[%sm%s\033[00m'
+    def dur(t):
+        s, t = t % 60, t // 60
+        m, t = t % 60, t // 60
+        h, d = t % 24, t // 24
+        if d > 0:
+            return '%id%ih%i\'%02i"' % (d, h, m, s)
+        elif h > 0:
+            return '%ih%i\'%02i"' % (h, m, s)
+        elif m > 0:
+            return '%i\'%02i"' % (m, s)
+        else:
+            return '%02is' % s
+    amount = ('+%i' if announcement[4] > 0 else '%i') % announcement[4]
+    c = '00'
+    time_until = announcement[3] - int(now)
+    if time_until >= 0:
+        if time_until < 10:
+            c = '41'
+        elif time_until < 60:
+            c = '31'
+        elif time_until < 60 * 60:
+            c = '33'
+        elif time_until < 24 * 60 * 60:
+            c = '32'
+    text %= (c, dur(abs(time_until)))
+    text = 'Leap: %s %s at end of UTC %s' % (amount, text, '%i-%02i-%0i' % announcement[:3])
+    if announcement[5] == LeapSeconds.SECONDARY:
+        text += ' (secondary)'
+    if announcement[5] == LeapSeconds.OUT_OF_BAND:
+        text += ' (out of band)'
+    bar.clear()
+    bar.draw_coloured_text(0, 10, 0, 2, text)
+
diff --git a/src/plugins/leapsec.py b/src/plugins/leapsec.py
new file mode 100644
index 0000000..f04ad8d
--- /dev/null
+++ b/src/plugins/leapsec.py
@@ -0,0 +1,134 @@
+# -*- python -*-
+'''
+xpybar – xmobar replacement written in python
+Copyright © 2014  Mattias Andrée (maandree@member.fsf.org)
+
+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 3 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
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+'''
+
+import calendar
+
+from util import *
+
+
+class LeapSeconds:
+    '''
+    Leap second announcement monitor
+    '''
+    
+    
+    PRIMARY = 0
+    '''
+    The leap occurs in a primarily preferred time slot
+    '''
+    
+    SECONDARY = 1
+    '''
+    The leap occurs in a secondarily preferred time slot
+    '''
+    
+    OUT_OF_BAND = 2
+    '''
+    The leap occurs out of band, not in any preferred time slot
+    '''
+    
+    
+    def __init__(self):
+        '''
+        Constructor
+        '''
+        url = 'http://maia.usno.navy.mil/ser7/leapsec.dat'
+        announcements = spawn_read('wget', url, '-O', '-')
+        while '  ' in announcements:
+            announcements = announcements.replace('  ', ' ')
+        announcements = announcements.replace('= ', '=').replace('=JD ', '=JD')
+        announcements = [announcement.lstrip().split(' ') for announcement in announcements.split('\n')]
+        test = lambda announcement : announcement.startswith('TAI-UTC=') or announcement.startswith('UTC-TAI=')
+        announcements = [announcement[:3] + list(filter(test, announcement)) for announcement in announcements]
+        MONTHS = { 'JAN' : 1
+                 , 'FEB' : 2
+                 , 'MAR' : 3
+                 , 'APR' : 4
+                 , 'MAY' : 5
+                 , 'JUN' : 6
+                 , 'JUL' : 7
+                 , 'AUG' : 8
+                 , 'SEP' : 9
+                 , 'OCT' : 10
+                 , 'NOV' : 11
+                 , 'DEC' : 12
+                 }
+        DAYS_OF_MONTHS = [-1, 31, 28, 31, 30, 31, 30, 30, 31, 30, 31, 30, 31]
+        def translate(announcement):
+            announcement[0] = int(announcement[0])
+            announcement[1] = MONTHS[announcement[1]]
+            announcement[2] = int(announcement[2]) - 1
+            if announcement[3].startswith('TAI-UTC='):
+                announcement[3] = int(announcement[3].split('=')[1].split('.')[0])
+            else:
+                announcement[3] = -(int(announcement[3].split('=')[1].split('.')[0]))
+            announcement.append(LeapSeconds.OUT_OF_BAND)
+            if announcement[2] == 0:
+                announcement[1] -= 1
+                if announcement[1] == 0:
+                    announcement[1] = 12
+                    announcement[0] -= 1
+                announcement[2] = DAYS_OF_MONTHS[announcement[1]]
+                if announcement[2] == 2:
+                    year = announcement[0]
+                    if ((year % 4 == 0) and not (year % 100 == 0)) or (year % 400 == 0):
+                        announcement[2] += 1
+                if announcement[1] in (6, 12):
+                    announcement[4] = LeapSeconds.PRIMARY
+                elif announcement[1] in (3, 9):
+                    announcement[4] = LeapSeconds.SECONDARY
+            return announcement
+        announcements = [translate(announcement) for announcement in announcements]
+        for i in reversed(range(len(announcements) - 1)):
+            announcements[i + 1][3] -= announcements[i][3]
+        self.announcements = announcements[1:]
+    
+    
+    def __len__(self):
+        '''
+        Get the number of available leap second announcements
+        
+        @return  The number of available leap second announcements
+        '''
+        return len(self.announcements)
+    
+    
+    def __getitem__(self, index):
+        '''
+        Get a leap second announcement
+        
+        @param   index:int?     The index of the announcement, negative for reversed chronological indexing
+        @return  :(year:int,    The year the leap second will occur or occurred (UTC)
+                   month:int,   The month [1, 12] the leap second will occur or occurred (UTC)
+                   day:int,     The day [1, 31] the leap second will occur or occurred (UTC)
+                   posix:int,   The POSIX timestamp the leap will occur or occurred.
+                                Keep in mind that POSIX time does not have leap seconds;
+                                if `amount == 1` then this time will represent 00:00:00 at
+                                the day directly after the day described by (`year`, `month`, `day`)
+                   amount:int,  The number of leap seconds introduced, can be negative but not zero
+                   annon:int)   Annonouncement class, either of:
+                                LeapSeconds.PRIMARY, LeapSeconds.SECONDARY, LeapSeconds.OUT_OF_BAND
+        '''
+        (y, m, d, a, t) = self.announcements[index]
+        s = 24 * 60 * 60 + a - 1
+        if a > 0:
+            s += 1
+        s = calendar.timegm((y, m, d, 0, 0, s))
+        return (y, m, d, s, a, t)
+