feat: add agendaupdate for time

Round trips don't work for all day events. The current output format
is to present them as events starting and ending at midnight of the
same day. But this keeps us from having events starting and ending at
midnight of the same day.

In the next commit I plan to change the output for all day events so
the time fields are blank.

Also:

- change signature of `Handler.patch()` to include `cal`, which is necessary to extract the timezone
- change default of `Handler.fieldnames` from `None` to `[]` to silence a mypy warning.

Partially implements insanum#550.

Author: michaelmhoffman

gcalcli/details.py

@@ -1,11 +1,15 @@
 """Handlers for specific details of events."""
 
 from collections import OrderedDict
+from datetime import datetime
 from itertools import chain
-from typing import List, Optional
+from typing import List
+
+from dateutil.parser import isoparse, parse
 
 FMT_DATE = '%Y-%m-%d'
 FMT_TIME = '%H:%M'
+TODAY = datetime.now().date()
 
 
 def _valid_title(event):
@@ -20,15 +24,15 @@ class Handler:
 
     # list of strings for fieldnames provided by this object
     # XXX: py36+: change to `fieldnames: List[str]`
-    fieldnames = None  # type: Optional[List[str]]
+    fieldnames = []  # type: List[str]
 
     @classmethod
     def get(cls, event):
         """Return simple string representation for columnar output."""
         raise NotImplementedError
 
     @classmethod
-    def patch(cls, event, fieldname, value):
+    def patch(cls, cal, event, fieldname, value):
         """Patch event from value."""
         raise NotImplementedError
 
@@ -41,8 +45,8 @@ def get(cls, event):
         return [cls._get(event).strip()]
 
     @classmethod
-    def patch(cls, event, fieldname, value):
-        cls._patch(cls, event, value)
+    def patch(cls, cal, event, fieldname, value):
+        return cls._patch(event, value)
 
 
 class SimpleSingleFieldHandler(SingleFieldHandler):
@@ -67,6 +71,35 @@ def get(cls, event):
         return [event['s'].strftime(FMT_DATE), event['s'].strftime(FMT_TIME),
                 event['e'].strftime(FMT_DATE), event['e'].strftime(FMT_TIME)]
 
+    @classmethod
+    def patch(cls, cal, event, fieldname, value):
+        instant_name, _, unit = fieldname.partition('_')
+
+        assert instant_name in {'start', 'end'}
+
+        if unit == 'date':
+            instant = event[instant_name] = {}
+            instant_date = parse(value, default=TODAY)
+
+            instant['date'] = instant_date.isoformat()
+            instant['dateTime'] = None  # clear any previous non-all-day time
+        else:
+            assert unit == 'time'
+
+            # If the time field is empty, do nothing.
+            # This enables all day events.
+            if not value.strip():
+                return
+
+            # date must be an earlier TSV field than time
+            instant = event[instant_name]
+            instant_date = isoparse(instant['date'])
+            instant_datetime = parse(value, default=instant_date)
+
+            instant['date'] = None  # clear all-day date
+            instant['dateTime'] = instant_datetime.isoformat()
+            instant['timeZone'] = cal['timeZone']
+
 
 class Url(Handler):
     """Handler for HTML and legacy Hangout links."""

gcalcli/gcal.py

@@ -1214,13 +1214,14 @@ def AgendaUpdate(self, file=sys.stdin):
         if len(self.cals) != 1:
             raise GcalcliError('Must specify a single calendar.')
 
-        cal_id = self.cals[0]['id']
+        cal = self.cals[0]
+        cal_id = cal['id']
 
         for row in reader:
             event = {}
 
             for fieldname, value in row.items():
-                FIELD_HANDLERS[fieldname].patch(event, value)
+                FIELD_HANDLERS[fieldname].patch(cal, event, fieldname, value)
 
             self._retry_with_backoff(
                 self.get_cal_service()