feat: add plugin auto-discovery via importlib

src/proxy_pool/plugins/discovery.py

@@ -0,0 +1,85 @@
+from __future__ import annotations
+
+import importlib
+import logging
+from pathlib import Path
+
+from proxy_pool.config import Settings
+from proxy_pool.plugins.protocols import Notifier, ProxyChecker, SourceParser
+from proxy_pool.plugins.registry import PluginRegistry
+
+logger = logging.getLogger(__name__)
+
+
+def discover_plugins(
+    package: str,
+    registry: PluginRegistry,
+    settings: Settings,
+) -> None:
+    try:
+        mod = importlib.import_module(package)
+    except ImportError:
+        logger.warning("Plugin package '%s' not found, skipping", package)
+        return
+
+    if hasattr(mod, "__path__"):
+        logger.warning(
+            "Plugin package '%s' has no __path__ attribute, skipping", package
+        )
+        return
+
+    package_path = Path(mod.__path__[0])
+
+    for path in sorted(package_path.rglob("*.py")):
+        if path.name.startswith("_"):
+            continue
+
+        relative = path.relative_to(package_path)
+        module_parts = relative.with_suffix("").parts
+        module_name = f"{package}.{'.'.join(module_parts)}"
+
+        try:
+            plugin_module = importlib.import_module(module_name)
+        except Exception:
+            logger.exception("Failed to import plugin module '%s'", module_name)
+            continue
+
+        if not hasattr(plugin_module, "create_plugin"):
+            continue
+
+        try:
+            plugin = plugin_module.create_plugin(settings)
+        except Exception:
+            logger.exception(
+                "Failed to create plugin from '%s'",
+                module_name,
+            )
+            continue
+
+        if plugin is None:
+            logger.debug(
+                "Plugin '%s' returned None (disabled by config)",
+                module_name,
+            )
+            continue
+
+        _register_plugin(registry, plugin, module_name)
+
+
+def _register_plugin(
+    registry: PluginRegistry,
+    plugin: object,
+    module_name: str,
+) -> None:
+    if isinstance(plugin, SourceParser):
+        registry.register_parser(plugin)
+    elif isinstance(plugin, ProxyChecker):
+        registry.register_checker(plugin)
+    elif isinstance(plugin, Notifier):
+        registry.register_notifier(plugin)
+    else:
+        logger.warning(
+            "Plugin from '%s' has unknown type: %s",
+            module_name,
+            type(plugin).__name__,
+        )