#!/usr/bin/env python3
# -*- coding: utf-8 -*-

"""
依赖注入容器
统一管理所有服务和组件的生命周期
"""

import logging
from typing import Dict, Any, Type, TypeVar, Optional, Callable
from functools import lru_cache

logger = logging.getLogger(__name__)

T = TypeVar('T')


class Container:
    """
    依赖注入容器
    
    功能:
    1. 单例管理 - 每个服务只创建一次
    2. 延迟加载 - 只在需要时创建
    3. 依赖解析 - 自动解析依赖关系
    
    使用示例:
    ```python
    # 注册服务
    Container.register(ConfigManager, lambda: ConfigManager())
    Container.register(AIAgent, lambda c: AIAgent(c.get(ConfigManager)))
    
    # 获取服务
    config = Container.get(ConfigManager)
    agent = Container.get(AIAgent)
    ```
    """
    
    _instances: Dict[Type, Any] = {}
    _factories: Dict[Type, Callable] = {}
    _initialized: bool = False
    
    @classmethod
    def register(cls, service_type: Type[T], factory: Callable[['Container'], T]):
        """
        注册服务工厂
        
        Args:
            service_type: 服务类型
            factory: 工厂函数，接收 Container 作为参数
        """
        cls._factories[service_type] = factory
        logger.debug(f"注册服务: {service_type.__name__}")
    
    @classmethod
    def get(cls, service_type: Type[T]) -> T:
        """
        获取服务实例
        
        Args:
            service_type: 服务类型
            
        Returns:
            服务实例 (单例)
        """
        if service_type not in cls._instances:
            if service_type not in cls._factories:
                raise ValueError(f"服务未注册: {service_type.__name__}")
            
            factory = cls._factories[service_type]
            cls._instances[service_type] = factory(cls)
            logger.debug(f"创建服务实例: {service_type.__name__}")
        
        return cls._instances[service_type]
    
    @classmethod
    def has(cls, service_type: Type) -> bool:
        """检查服务是否已注册"""
        return service_type in cls._factories
    
    @classmethod
    def reset(cls):
        """重置容器 (主要用于测试)"""
        cls._instances.clear()
        cls._factories.clear()
        cls._initialized = False
        logger.info("容器已重置")
    
    @classmethod
    def initialize(cls):
        """
        初始化容器，注册所有默认服务
        """
        if cls._initialized:
            return
        
        logger.info("初始化依赖注入容器...")
        
        # 注册配置管理器
        from core.config import ConfigManager
        cls.register(ConfigManager, lambda c: ConfigManager())
        
        # 注册 AI Agent
        from core.ai import AIAgent
        from core.config import AIModelConfig
        def create_ai_agent(c: 'Container') -> AIAgent:
            config_manager = c.get(ConfigManager)
            ai_config = config_manager.get_config('ai_model', AIModelConfig)
            return AIAgent(ai_config)
        cls.register(AIAgent, create_ai_agent)
        
        # 注册 Prompt Registry
        from domain.prompt import PromptRegistry
        cls.register(PromptRegistry, lambda c: PromptRegistry('prompts'))
        
        # 注册 OutputManager (延迟创建)
        from libs.utils.file_io import OutputManager
        import uuid
        from datetime import datetime
        def create_output_manager(c: 'Container') -> OutputManager:
            run_id = f"api_request-{datetime.now().strftime('%Y%m%d-%H%M%S')}-{str(uuid.uuid4())[:8]}"
            return OutputManager('result', run_id)
        cls.register(OutputManager, create_output_manager)
        
        cls._initialized = True
        logger.info("依赖注入容器初始化完成")
    
    @classmethod
    def get_or_create(cls, service_type: Type[T], factory: Callable[[], T]) -> T:
        """
        获取服务，如果不存在则使用提供的工厂创建
        
        Args:
            service_type: 服务类型
            factory: 备用工厂函数
        """
        if service_type not in cls._instances:
            if service_type not in cls._factories:
                cls._instances[service_type] = factory()
            else:
                cls._instances[service_type] = cls._factories[service_type](cls)
        
        return cls._instances[service_type]


# 便捷函数
def get_service(service_type: Type[T]) -> T:
    """获取服务的便捷函数"""
    Container.initialize()
    return Container.get(service_type)


def inject(*service_types: Type):
    """
    依赖注入装饰器
    
    使用示例:
    ```python
    @inject(ConfigManager, AIAgent)
    def my_function(config, agent, other_param):
        ...
    ```
    """
    def decorator(func):
        def wrapper(*args, **kwargs):
            Container.initialize()
            injected = [Container.get(t) for t in service_types]
            return func(*injected, *args, **kwargs)
        return wrapper
    return decorator