from typing import Dict, List, Optional, Type
from plugin_common.plugin_interface import PluginInterface, PluginStatus


class PluginRegistry:
    """插件注册表，维护已加载插件的信息和状态"""
    
    _instance = None
    
    def __new__(cls):
        """单例模式"""
        if cls._instance is None:
            cls._instance = super(PluginRegistry, cls).__new__(cls)
            cls._instance._plugins = {}
        return cls._instance
    
    def register(self, plugin: PluginInterface) -> bool:
        """
        注册插件
        
        Args:
            plugin: 插件实例
            
        Returns:
            注册是否成功
        """
        if plugin.name in self._plugins:
            print(f"插件 {plugin.name} 已存在")
            return False
        
        self._plugins[plugin.name] = plugin
        return True
    
    def unregister(self, plugin_name: str) -> bool:
        """
        注销插件
        
        Args:
            plugin_name: 插件名称
            
        Returns:
            注销是否成功
        """
        if plugin_name not in self._plugins:
            print(f"插件 {plugin_name} 不存在")
            return False
        
        del self._plugins[plugin_name]
        return True
    
    def get_plugin(self, plugin_name: str) -> Optional[PluginInterface]:
        """
        获取插件实例
        
        Args:
            plugin_name: 插件名称
            
        Returns:
            插件实例，不存在返回None
        """
        return self._plugins.get(plugin_name)
    
    def get_all_plugins(self) -> Dict[str, PluginInterface]:
        """
        获取所有插件
        
        Returns:
            插件字典，键为插件名称，值为插件实例
        """
        return self._plugins.copy()
    
    def get_plugins_by_status(self, status: PluginStatus) -> List[PluginInterface]:
        """
        获取指定状态的插件
        
        Args:
            status: 插件状态
            
        Returns:
            插件列表
        """
        return [p for p in self._plugins.values() if p.status == status]
    
    def get_plugins_by_type(self, plugin_type: Type) -> List[PluginInterface]:
        """
        获取指定类型的插件
        
        Args:
            plugin_type: 插件类型
            
        Returns:
            插件列表
        """
        return [p for p in self._plugins.values() if isinstance(p, plugin_type)]