From 10181669ba80ee2f629935d09909ad7cf757a989 Mon Sep 17 00:00:00 2001
From: dgtlmoon <dgtlmoon@gmail.com>
Date: Tue, 12 Sep 2023 15:39:10 +0200
Subject: [PATCH] WIP - Plugin architecture

---
 changedetectionio/processors/__init__.py | 25 +++++++++++++++++++++---
 changedetectionio/store.py               | 14 +++++++++++++
 changedetectionio/update_worker.py       | 21 ++++++++++++++++++--
 3 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/changedetectionio/processors/__init__.py b/changedetectionio/processors/__init__.py
index 225e9c8a..d872607b 100644
--- a/changedetectionio/processors/__init__.py
+++ b/changedetectionio/processors/__init__.py
@@ -18,7 +18,26 @@ class difference_detection_processor():
 
 
 def available_processors():
+    import importlib
+    import pkgutil
+
     from . import restock_diff, text_json_diff
-    x=[('text_json_diff', text_json_diff.name), ('restock_diff', restock_diff.name)]
-    # @todo Make this smarter with introspection of sorts.
-    return x
+
+    processors = [('text_json_diff', text_json_diff.name), ('restock_diff', restock_diff.name)]
+
+    discovered_plugins = {
+        name: importlib.import_module(name)
+        for finder, name, ispkg
+        in pkgutil.iter_modules()
+        if name.startswith('changedetectionio-plugin-')
+    }
+
+    try:
+        for name, plugin in discovered_plugins.items():
+            if hasattr(plugin, 'processors'):
+                for machine_name, desc in plugin.processors.items():
+                    processors.append((machine_name, desc))
+    except Exception as e:
+        print (f"Problem fetching one or more plugins")
+
+    return processors
diff --git a/changedetectionio/store.py b/changedetectionio/store.py
index a8082cd5..52032d09 100644
--- a/changedetectionio/store.py
+++ b/changedetectionio/store.py
@@ -126,6 +126,7 @@ class ChangeDetectionStore:
 
         self.needs_write = True
 
+        self.scan_plugins()
         # Finally start the thread that will manage periodic data saves to JSON
         save_data_thread = threading.Thread(target=self.save_datastore).start()
 
@@ -612,6 +613,19 @@ class ChangeDetectionStore:
     def tag_exists_by_name(self, tag_name):
         return any(v.get('title', '').lower() == tag_name.lower() for k, v in self.__data['settings']['application']['tags'].items())
 
+    def scan_plugins(self):
+        import importlib
+        import pkgutil
+
+        discovered_plugins = {
+            name: importlib.import_module(name)
+            for finder, name, ispkg
+            in pkgutil.iter_modules()
+            if name.startswith('changedetectionio-plugin-')
+        }
+
+        return discovered_plugins
+
     # Run all updates
     # IMPORTANT - Each update could be run even when they have a new install and the schema is correct
     #             So therefor - each `update_n` should be very careful about checking if it needs to actually run
diff --git a/changedetectionio/update_worker.py b/changedetectionio/update_worker.py
index 63a0aab4..bd119773 100644
--- a/changedetectionio/update_worker.py
+++ b/changedetectionio/update_worker.py
@@ -1,6 +1,8 @@
+import importlib
 import os
-import threading
+import pkgutil
 import queue
+import threading
 import time
 
 from changedetectionio import content_fetcher
@@ -229,13 +231,28 @@ class update_worker(threading.Thread):
                     now = time.time()
 
                     try:
-                        processor = self.datastore.data['watching'][uuid].get('processor','text_json_diff')
+                        processor = self.datastore.data['watching'][uuid].get('processor', 'text_json_diff')
 
                         # @todo some way to switch by name
                         if processor == 'restock_diff':
                             update_handler = restock_diff.perform_site_check(datastore=self.datastore)
                         else:
                             # Used as a default and also by some tests
+                            discovered_plugins = {
+                                name: importlib.import_module(name)
+                                for finder, name, ispkg
+                                in pkgutil.iter_modules()
+                                if name.startswith('changedetectionio-plugin-')
+                            }
+
+                            for module_name, plugin in discovered_plugins.items():
+                                if hasattr(plugin, 'processors'):
+                                    for machine_name, desc in plugin.processors:
+                                        if machine_name == processor:
+                                            module = importlib.import_module(f"{module_name}.processors.{plugin}")
+                                            update_handler = module.perform_site_check(datastore=self.datastore)
+                                            #processors.append((machine_name, desc))
+
                             update_handler = text_json_diff.perform_site_check(datastore=self.datastore)
 
                         changed_detected, update_obj, contents = update_handler.run(uuid, skip_when_checksum_same=queued_item_data.item.get('skip_when_checksum_same'))