bot, plugins: fix per-channel configuration by plugin name

When this feature was first implemented, core plugins and user plugins
(from `~/.sopel/modules`) both loaded in a similar way. Their Python
module names matched the file names, and nobody thought to test how this
feature worked (or might not) for `sopel_modules` packages. Certainly,
no one thought to test entry-point plugins (new in 7.0, implemented
*after* this was).

To make a long story short (the full narrative is summarized in #1839),
this feature was never going to work as intended in all cases. Changes
to the plugin machinery simply made it *also* not work for core plugins,
which made the shortcomings of its implementation much more obvious.

Before passing the module contents back to `bot` during registration,
the `plugins.handlers.PyModulePlugin` class (and derivatives) now adds a
`plugin_name` attribute to each "relevant part" (callable). This is
immediately useful for improving the per-channel filtering so it works
as expected, and will likely find more use in the future (e.g. as a
substitute for the long-deprecated `bot.command_groups` property).

In `bot`, in addition to using the new callable attribute instead of
Python's module name for per-channel filtering, I also added log output
to debug mode for completeness.

sopel/bot.py

@@ -574,16 +574,28 @@ def call(self, func, sopel, trigger):
 
                 # if "*" is used, we are disabling all plugins on provided channel
                 if '*' in disabled_plugins:
+                    LOGGER.debug(
+                        "All plugins disabled in %s; skipping execution of %s.%s",
+                        trigger.sender, func.plugin_name, func.__name__
+                    )
                     return
-                if func.__module__ in disabled_plugins:
+                if func.plugin_name in disabled_plugins:
+                    LOGGER.debug(
+                        "Plugin %s is disabled in %s; skipping execution of %s",
+                        func.plugin_name, trigger.sender, func.__name__
+                    )
                     return
 
             # disable chosen methods from plugins
             if 'disable_commands' in channel_config:
                 disabled_commands = literal_eval(channel_config.disable_commands)
 
-                if func.__module__ in disabled_commands:
-                    if func.__name__ in disabled_commands[func.__module__]:
+                if func.plugin_name in disabled_commands:
+                    if func.__name__ in disabled_commands[func.plugin_name]:
+                        LOGGER.debug(
+                            "Skipping execution of %s.%s in %s: disabled_commands matched",
+                            func.plugin_name, func.__name__, trigger.sender
+                        )
                         return
 
         try:

sopel/plugins/handlers.py

@@ -36,6 +36,7 @@
 import inspect
 import imp
 import importlib
+import itertools
 import os
 
 from sopel import loader
@@ -259,6 +260,10 @@ def has_setup(self):
 
     def register(self, bot):
         relevant_parts = loader.clean_module(self._module, bot.config)
+        for part in itertools.chain(*relevant_parts):
+            # annotate all callables in relevant_parts with `plugin_name`
+            # attribute to make per-channel config work; see #1839
+            setattr(part, 'plugin_name', self.name)
         bot.add_plugin(self, *relevant_parts)
 
     def unregister(self, bot):