Add bill option; fix negative minutes

The minutes were positive even when the hours were negative. This is obviously undesired, we want the entire time to be negative. That was fixed.

tx

@@ -10,6 +10,28 @@ def get_current_date():
 def get_timefile_line(date, time, desc):
     return date + " " + time + " " + desc + "\n"
 
+def get_total(filename):
+    with open(filename, 'r') as time_file:
+        total_time = timedelta()
+
+        for line in time_file:
+            date_time_description = line.split(" ", 2)
+            
+            hours, minutes = date_time_description[1].split(':', 1)
+            
+            # Parse the time to integers
+            hours_int = int(hours)
+            minutes_int = int(minutes)
+            
+            # Make sure that both the hours and the minutes are negative if there's a "-" before the time
+            if hours_int < 0: minutes_int *= -1
+            
+            delta = timedelta(hours=hours_int, minutes=minutes_int)
+            
+            total_time += delta
+
+        return total_time
+
 # Parse command line arguments
 parser = argparse.ArgumentParser(prog='time.txt', description="Description")
 subparsers = parser.add_subparsers(help='sub-command help', dest='mode')
@@ -25,6 +47,11 @@ parser_b.add_argument("date", nargs='?', default=get_current_date())
 parser_b.add_argument("time")
 parser_b.add_argument("description")
 
+parser_b = subparsers.add_parser('bill', help='b help')
+parser_b.add_argument("date", nargs='?', default=get_current_date())
+parser_b.add_argument("time")
+parser_b.add_argument("description")
+
 parser_c = subparsers.add_parser('create', help='b help')
 
 args = parser.parse_args()
@@ -32,23 +59,22 @@ args = parser.parse_args()
 filename = args.file if args.file else 'time.txt'
 
 if not args.mode or args.mode == "total":
-    with open(filename, 'r') as time_file:
-        total_time = timedelta()
-
-        for line in time_file:
-            date_time_description = line.split(" ", 2)
-            
-            hours, minutes = date_time_description[1].split(':', 1)
-            delta = timedelta(hours=int(hours), minutes=int(minutes))
-            
-            total_time += delta
-
-        print('Total time: ', total_time)
+    print("Total time:", get_total(filename))
 
 elif args.mode == "add":
     with open(filename, 'a') as time_file:
+        # TODO: Validate date and time
         time_file.write(get_timefile_line(args.date, args.time, args.description))
         
+    print("New total:", get_total(filename))
+
+elif args.mode == "bill":
+    with open(filename, 'a') as time_file:
+        # TODO: Validate date and time
+        time_file.write(get_timefile_line(args.date, "-" + args.time, args.description))
+        
+    print("New total:", get_total(filename))
+
 elif args.mode == "create":
     if (os.path.exists(filename)):
         print("Error: File", filename, "already exists, can't create a new one!")