Add the previous/next year/month links to the month view

calsocial/calendar_system/gregorian.py

@@ -1,9 +1,19 @@
 from datetime import datetime, timedelta
+from functools import wraps
+
 from flask_babelex import lazy_gettext as _
 
 from . import CalendarSystem
 
 
+def to_timestamp(func):
+    @wraps(func)
+    def decorator(*args, **kwargs):
+        return func(*args, **kwargs).timestamp()
+
+    return decorator
+
+
 class GregorianCalendar(CalendarSystem):
     __name__ = _('Gregorian')
 
@@ -12,6 +22,21 @@ class GregorianCalendar(CalendarSystem):
     START_DAY = 0
     END_DAY = 7
 
+    month_names = (
+        _('January'),
+        _('February'),
+        _('March'),
+        _('April'),
+        _('May'),
+        _('June'),
+        _('July'),
+        _('August'),
+        _('September'),
+        _('October'),
+        _('November'),
+        _('December'),
+    )
+
     day_names = (
         _('Monday'),
         _('Tuesday'),
@@ -47,6 +72,76 @@ class GregorianCalendar(CalendarSystem):
 
         return day_list
 
+    @property
+    @to_timestamp
+    def prev_year(self):
+        return self.timestamp.replace(year=self.timestamp.year - 1)
+
+    @property
+    def prev_year_year(self):
+        return self.timestamp.replace(year=self.timestamp.year - 1).year
+
+    @property
+    @to_timestamp
+    def prev_month(self):
+        if self.timestamp.month == 1:
+            return self.prev_year.replace(month=12)
+
+        return self.timestamp.replace(month=self.timestamp.month - 1)
+
+    @property
+    def prev_month_name(self):
+        if self.timestamp.month == 1:
+            ts = self.prev_year.replace(month=12)
+        else:
+            ts = self.timestamp.replace(month=self.timestamp.month - 1)
+
+        return self.month_names[ts.month - 1]
+
+    @property
+    @to_timestamp
+    def next_month(self):
+        if self.timestamp.month == 12:
+            return self.next_year.replace(month=1)
+
+        return self.timestamp.replace(month=self.timestamp.month + 1)
+
+    @property
+    def next_month_name(self):
+        if self.timestamp.month == 12:
+            ts = self.prev_year.replace(month=1)
+        else:
+            ts = self.timestamp.replace(month=self.timestamp.month + 1)
+
+        return self.month_names[ts.month - 1]
+
+    @property
+    @to_timestamp
+    def next_year(self):
+        return self.timestamp.replace(year=self.timestamp.year + 1)
+
+    @property
+    def next_year_year(self):
+        return self.timestamp.replace(year=self.timestamp.year + 1).year
+
+    @property
+    def has_today(self):
+        now = datetime.utcnow()
+        month_start_timestamp = self.timestamp.replace(day=1,
+                                                       hour=0,
+                                                       minute=0,
+                                                       second=0,
+                                                       microsecond=0)
+
+        if self.timestamp.month == 12:
+            next_month = 1
+        else:
+            next_month = self.timestamp.month + 1
+
+        month_end_timestamp = month_start_timestamp.replace(month=next_month)
+
+        return now >= month_start_timestamp and now < month_end_timestamp
+
     def day_events(self, date, user=None):
         from ..models import Event
 
@@ -55,7 +150,7 @@ class GregorianCalendar(CalendarSystem):
         if user:
             events = events.filter(Event.user == user)
 
-        start_timestamp = date.replace(hour=0, minute=0, second=0, microsecond=0)
+        start_timestamp = self.timestamp.replace(hour=0, minute=0, second=0, microsecond=0)
         end_timestamp = start_timestamp + timedelta(days=1)
 
         events = events.filter(((Event.start_time >= start_timestamp) & (Event.start_time < end_timestamp)) |