main: better task invite message

main.py

@@ -40,6 +40,18 @@ def necessary_changes(current: List[T], desired: List[T]) -> Changes[T]:
 
     return changes
 
+def format_seconds(seconds: float) -> str:
+    seconds = int(seconds)
+
+    if seconds < 60:
+        return f"{seconds} seconds"
+    elif seconds < 3600:
+        return f"{seconds//60} minutes"
+    elif seconds < 86400:
+        return f"{seconds//3600} hours"
+    else:
+        return f"{seconds//86400} days"
+
 class SignalAPI:
 
     def __init__(self, apiurl, number):
@@ -396,7 +408,16 @@ class LabCleaningBot:
                     reqs = reqs.unwrap()
 
                 for request in reqs:
-                    message = SendMessageSimple(message=task.name, recipients=[request.user.name])
+                    seconds_to_due = (task.due - request.requested_at).total_seconds()
+                    text = f"""Hi!
+
+You have been requested to participate in the task: {task.name} (starts in {format_seconds(seconds_to_due)}).
+
+To accept the request, react with 👍. To reject, react with any other emoji.
+
+You have time to answer for {format_seconds(task.timeout)}."""
+
+                    message = SendMessageSimple(message=text, recipients=[request.user.name])
                     res = self.api.send_message(message)
 
                     if is_ok(res):