import os
import configparser
from typing import Dict, Any, Optional, List


class IniHandlerError(Exception):
    """INI处理器异常基类"""
    def __init__(self, message: str, file_path: str = None):
        self.file_path = file_path
        if file_path:
            message = f"{message} (文件: {file_path})"
        super().__init__(message)

class IniHandler:
    """
    INI文件操作处理器（基于文件路径的缓存）
    """
    
    _instances = {}  # 按文件路径缓存的实例
    
    def __new__(cls, file_path: str):
        if file_path not in cls._instances:
            instance = super().__new__(cls)
            instance._file_path = file_path
            instance._config = None  # 单个文件的配置对象
            cls._instances[file_path] = instance
        return cls._instances[file_path]
    
    def __init__(self, file_path: str):
        """
        初始化INI处理器
        
        Args:
            file_path: INI文件路径
        """
        # 文件路径已经在__new__中设置，这里不需要重复设置
        pass
    
    def load_config(self) -> configparser.ConfigParser:
        """
        加载并缓存INI配置文件
        """
        if self._config is not None:
            return self._config
        
        if not os.path.exists(self._file_path):
            raise IniHandlerError("INI文件不存在", self._file_path)
        
        try:
            config = configparser.ConfigParser()
            config.read(self._file_path, encoding='utf-8')
            self._config = config
            return config
        except Exception as e:
            raise IniHandlerError(f"读取INI文件失败: {e}", self._file_path)
    
        
    def get_value(self, section: str, option: str) -> Any:
        """
        获取INI文件中的值
        
        Args:
            section: 节名
            option: 选项名
            default: 默认值
            
        Returns:
            获取的值，如果不存在则返回默认值
        """
        try:
            config = self.load_config()
            if config.has_section(section) and config.has_option(section, option):
                return config.get(section, option)
        except IniHandlerError:
            # 文件不存在或读取失败时返回默认值
            return default
        except Exception as e:
            raise IniHandlerError(f"获取INI值失败: {e}", self._file_path)
    
    def get_int_value(self, section: str, option: str) -> int:
        """
        获取INI文件中的整数值
        
        Args:
            section: 节名
            option: 选项名
            default: 默认值
            
        Returns:
            获取的整数值，如果不存在或转换失败则返回默认值
        """
        try:
            config = self.load_config()
            if config.has_section(section) and config.has_option(section, option):
                return config.getint(section, option)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"获取INI整数值失败: {e}", self._file_path)

    def get_float_value(self, section: str, option: str) -> float:
        """
        获取INI文件中的浮点数值  
        Args:
            section: 节名
            option: 选项名
            default: 默认值
            
        Returns:
            获取的浮点数值，如果不存在或转换失败则返回默认值
        """
        try:
            config = self.load_config()
            if config.has_section(section) and config.has_option(section, option):
                return config.getfloat(section, option)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"获取INI浮点数值失败: {e}", self._file_path)

    def get_boolean_value(self, section: str, option: str) -> bool:
        """
        获取INI文件中的布尔值     
        Args:
            section: 节名
            option: 选项名
            default: 默认值
            
        Returns:
            获取的布尔值，如果不存在或转换失败则返回默认值
        """
        try:
            config = self.load_config()
            if config.has_section(section) and config.has_option(section, option):
                return config.getboolean(section, option)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"获取INI布尔值失败: {e}", self._file_path)
    

    def get_section(self, section: str) -> Dict[str, str]:
        """
        获取INI文件中的整个节    
        Args:
            section: 节名         
        Returns:
            节中所有键值对的字典，如果节不存在则返回空字典
        """
        try:
            config = self.load_config()
            if config.has_section(section):
                return dict(config[section])
            return {}
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"获取INI节失败: {e}", self._file_path)
    
    def get_sections(self) -> List[str]:
        """
        获取INI文件中的所有节名     
        Returns:
            节名列表
        """
        try:
            config = self.load_config()
            return config.sections()
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"获取INI节名列表失败: {e}", self._file_path)
    
    def remove_section(self, section: str) -> None:
        """
        移除INI文件中的节      
        Args:
            section: 节名
        """
        try:
            config = self.load_config()
            if config.has_section(section):
                config.remove_section(section)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"移除INI节失败: {e}", self._file_path)
    
    def remove_option(self, section: str, option: str) -> None:
        """
        移除INI文件中的选项    
        Args:
            section: 节名
            option: 选项名
        """
        try:
            config = self.load_config()
            if config.has_section(section) and config.has_option(section, option):
                config.remove_option(section, option)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"移除INI选项失败: {e}", self._file_path)
    
    def has_section(self, section: str) -> bool:
        """
        检查INI文件中是否存在指定的节
        
        Args:
            section: 节名
            
        Returns:
            bool: 是否存在
        """
        try:
            config = self.load_config()
            return config.has_section(section)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"检查INI节失败: {e}", self._file_path)
    
    def has_option(self, section: str, option: str) -> bool:
        """
        检查INI文件中是否存在指定的选项
        
        Args:
            section: 节名
            option: 选项名          
        Returns:
            bool: 是否存在
        """
        try:
            config = self.load_config()
            return config.has_option(section, option)
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"检查INI选项失败: {e}", self._file_path)
    
    def write_ini_file(self) -> bool:
        """
        写入INI文件（持久化,写入前先set_value,set_value设置1或多个值后调用此方法）    
        Returns:
            bool: 是否写入成功
        """
        try:            
            # 确保目录存在
            dir_path = os.path.dirname(self._file_path)
            if dir_path and not os.path.exists(dir_path):
                os.makedirs(dir_path)            
            # 写入文件
            with open(self._file_path, 'w', encoding='utf-8') as f:
                self._config.write(f) 
            return True
        except Exception as e:
            raise IniHandlerError(f"写入INI文件失败: {e}", self._file_path)

    def set_value(self, section: str, option: str, value: Any) -> None:
        """
        设置INI文件中的值
        
        Args:
            section: 节名
            option: 选项名
            value: 要设置的值
        """
        try:
            config = self.load_config()
            if not config.has_section(section):
                config.add_section(section)
            config.set(section, option, str(value))
        except IniHandlerError:
            raise
        except Exception as e:
            raise IniHandlerError(f"设置INI值失败: {e}", self._file_path)