fix: Check if the length of the previous IO overlaps with the new IO

When applying the PiCtory configuration, all IOs are now checked to
see if they overlap with the previous ones. If an overlap is
detected, the IO is ignored and a warning is given to the user.

Signed-off-by: Sven Sager <akira@narux.de>

src/revpimodio2/io.py

@@ -5,6 +5,7 @@ __copyright__ = "Copyright (C) 2023 Sven Sager"
 __license__ = "LGPLv2"
 
 import struct
+import warnings
 from re import match as rematch
 from threading import Event
 
@@ -242,11 +243,10 @@ class IOList(object):
                     "attribute {0} already exists - can not set io".format(new_io._name)
                 )
 
-            if type(new_io) is StructIO:
+            do_replace = type(new_io) is StructIO
+            if do_replace:
                 self.__private_replace_oldio_with_newio(new_io)
 
-            object.__setattr__(self, new_io._name, new_io)
-
             # Bytedict für Adresszugriff anpassen
             if new_io._bitshift:
                 if len(self.__dict_iobyte[new_io.address]) != 8:
@@ -261,10 +261,54 @@ class IOList(object):
                         None,
                         None,
                     ]
+                # Check for overlapping IOs
+                if (
+                    not do_replace
+                    and self.__dict_iobyte[new_io.address][new_io._bitaddress] is not None
+                ):
+                    warnings.warn(
+                        "ignore io '{0}', as an io already exists at the address '{1} Bit {2}'. "
+                        "this can be caused by an incorrect pictory configuration.".format(
+                            new_io.name,
+                            new_io.address,
+                            new_io._bitaddress,
+                        ),
+                        Warning,
+                    )
+                    return
+
                 self.__dict_iobyte[new_io.address][new_io._bitaddress] = new_io
             else:
+                # Search the previous IO to calculate the length
+                offset_end = new_io.address
+                search_index = new_io.address
+                while search_index >= 0:
+                    previous_io = self.__dict_iobyte[search_index]
+                    if len(previous_io) == 8:
+                        # Bits on this address are always 1 byte
+                        offset_end -= 1
+                    elif len(previous_io) == 1:
+                        # Found IO, calculate offset + length of IO
+                        offset_end = previous_io[0].address + previous_io[0].length
+                        break
+                    search_index -= 1
+
+                # Check if the length of the previous IO overlaps with the new IO
+                if offset_end > new_io.address:
+                    warnings.warn(
+                        "ignore io '{0}', as an io already exists at the address '{1}'. "
+                        "this can be caused by an incorrect pictory configuration.".format(
+                            new_io.name,
+                            new_io.address,
+                        ),
+                        Warning,
+                    )
+                    return
+
                 self.__dict_iobyte[new_io.address].append(new_io)
 
+            object.__setattr__(self, new_io._name, new_io)
+
             if type(new_io) is StructIO:
                 new_io._parentdevice._update_my_io_list()
         else: