Leave start and end values if we're not modifying them

main.py

@@ -2,18 +2,18 @@
 Take existing calendar and update it slightly
 """
 
-from datetime import datetime, time, timedelta
+from datetime import date, datetime, time, timedelta
 
 import requests
 from flask import Flask, Response, request
-from icalendar import Calendar, Event  # type: ignore[import]
+from icalendar import Calendar, Event
 from werkzeug.middleware.proxy_fix import ProxyFix
 
 app = Flask(__name__)
 app.wsgi_app = ProxyFix(app.wsgi_app, x_proto=1)  # type: ignore[assignment]
 
 
-@app.route('/', methods=['get'])
+@app.route("/", methods=["get"])
 def process() -> Response:
     """
     Fetch ICS url and convert from Events to Todos
@@ -23,41 +23,53 @@ def process() -> Response:
     """
 
     # Fetch existing calendar
-    orig = requests.get(request.args['url'])
-    days = request.args.get('days', '0')
-    hours = request.args.get('hours', '0')
-    mins = request.args.get('mins', '0')
+    orig = requests.get(request.args["url"], timeout=30)
+    days = int(request.args.get("days", "0"))
+    hours = int(request.args.get("hours", "0"))
+    mins = int(request.args.get("mins", "0"))
 
     orig_cal = Calendar.from_ical(orig.text)
     cal = Calendar()
 
-    cal.add('version', '2.0')
+    cal.add("version", "2.0")
     cal.add(
-        'prodid',
-        '-//Scott Wallace//event2task//EN',
+        "prodid",
+        "-//Scott Wallace//event2task//EN",
     )
 
     for component in orig_cal.subcomponents:
         if isinstance(component, Event):
             entry = Event()
-            entry.add('description', component['description'])
-            entry.add('dtstamp', component['dtstamp'])
-            entry.add(
-                'dtstart',
-                datetime.combine(component.decoded('dtstart'), time(0))
-                + timedelta(days=int(days), hours=int(hours), minutes=int(mins)),
-            )
-            entry.add(
-                'dtend',
-                datetime.combine(component.decoded('dtend'), time(0))
-                + timedelta(days=int(days), hours=int(hours), minutes=int(mins)),
-            )
-            entry.add('summary', component['summary'])
-            entry.add('uid', component['uid'])
+
+            entry.add("description", component["description"])
+            entry.add("dtstamp", component["dtstamp"])
+            if days or hours or mins:
+                start = component.decoded("dtstart")
+                end = component.decoded("dtend")
+                if isinstance(start, date):
+                    entry.add(
+                        "dtstart",
+                        datetime.combine(start, time(0))
+                        + timedelta(days=days, hours=hours, minutes=mins),
+                    )
+                if isinstance(end, date):
+                    entry.add(
+                        "dtend",
+                        datetime.combine(end, time(0))
+                        + timedelta(days=days, hours=hours, minutes=mins),
+                    )
+
+            if not entry.get("dtstart"):
+                entry.add("dtstart", component["dtstart"])
+            if not entry.get("dtend"):
+                entry.add("dtend", component["dtend"])
+
+            entry.add("summary", component["summary"])
+            entry.add("uid", component["uid"])
 
             cal.add_component(entry)
 
     return Response(
-        cal.to_ical().decode().replace('\\r\\n', '\n').strip(),
-        headers={'content-type': 'text/calendar; charset=UTF-8'},
+        cal.to_ical().decode().replace("\\r\\n", "\n").strip(),
+        headers={"content-type": "text/calendar; charset=UTF-8"},
     )