⚡ improve plugin system (#1011)

nonebot/plugin/__init__.py

@@ -35,14 +35,77 @@ FrontMatter:
     description: nonebot.plugin 模块
 """
 
-from typing import List, Optional
+from itertools import chain
+from types import ModuleType
 from contextvars import ContextVar
+from typing import Set, Dict, List, Optional
 
+_plugins: Dict[str, "Plugin"] = {}
 _managers: List["PluginManager"] = []
 _current_plugin: ContextVar[Optional["Plugin"]] = ContextVar(
     "_current_plugin", default=None
 )
 
+
+def _module_name_to_plugin_name(module_name: str) -> str:
+    return module_name.rsplit(".", 1)[-1]
+
+
+def _new_plugin(
+    module_name: str, module: ModuleType, manager: "PluginManager"
+) -> "Plugin":
+    plugin_name = _module_name_to_plugin_name(module_name)
+    if plugin_name in _plugins:
+        raise RuntimeError("Plugin already exists! Check your plugin name.")
+    plugin = Plugin(plugin_name, module, module_name, manager)
+    _plugins[plugin_name] = plugin
+    return plugin
+
+
+def _revert_plugin(plugin: "Plugin") -> None:
+    if plugin.name not in _plugins:
+        raise RuntimeError("Plugin not found!")
+    del _plugins[plugin.name]
+
+
+def get_plugin(name: str) -> Optional["Plugin"]:
+    """获取已经导入的某个插件。
+
+    如果为 `load_plugins` 文件夹导入的插件，则为文件(夹)名。
+
+    参数:
+        name: 插件名，即 {ref}`nonebot.plugin.plugin.Plugin.name`。
+    """
+    return _plugins.get(name)
+
+
+def get_plugin_by_module_name(module_name: str) -> Optional["Plugin"]:
+    """通过模块名获取已经导入的某个插件。
+
+    如果提供的模块名为某个插件的子模块，同样会返回该插件。
+
+    参数:
+        module_name: 模块名，即 {ref}`nonebot.plugin.plugin.Plugin.module_name`。
+    """
+    splits = module_name.split(".")
+    loaded = {plugin.module_name: plugin for plugin in _plugins.values()}
+    while splits:
+        name = ".".join(splits)
+        if name in loaded:
+            return loaded[name]
+        splits.pop()
+
+
+def get_loaded_plugins() -> Set["Plugin"]:
+    """获取当前已导入的所有插件。"""
+    return set(_plugins.values())
+
+
+def get_available_plugin_names() -> Set[str]:
+    """获取当前所有可用的插件名（包含尚未加载的插件）。"""
+    return {*chain.from_iterable(manager.available_plugins for manager in _managers)}
+
+
 from .on import on as on
 from .manager import PluginManager
 from .export import Export as Export
@@ -61,7 +124,6 @@ from .on import CommandGroup as CommandGroup
 from .on import MatcherGroup as MatcherGroup
 from .on import on_fullmatch as on_fullmatch
 from .on import on_metaevent as on_metaevent
-from .plugin import get_plugin as get_plugin
 from .load import load_plugins as load_plugins
 from .on import on_startswith as on_startswith
 from .load import load_from_json as load_from_json
@@ -69,5 +131,4 @@ from .load import load_from_toml as load_from_toml
 from .on import on_shell_command as on_shell_command
 from .load import load_all_plugins as load_all_plugins
 from .load import load_builtin_plugin as load_builtin_plugin
-from .plugin import get_loaded_plugins as get_loaded_plugins
 from .load import load_builtin_plugins as load_builtin_plugins