import json
import os
import logging
from config_validator import ConfigValidator

class ConfigManager:
    """配置文件管理器"""
    
    def __init__(self, config_path="../config/config.json"):
        self.config_path = config_path
        self.config = None
        self.load_config()
    
    def load_config(self):
        """加载配置文件"""
        try:
            if not os.path.exists(self.config_path):
                # 尝试从备份恢复
                backup_path = self.config_path + ".bak"
                if os.path.exists(backup_path):
                    logging.warning(f"Main config not found, using backup: {backup_path}")
                    with open(backup_path, 'r') as src, open(self.config_path, 'w') as dst:
                        config_data = src.read()
                        dst.write(config_data)
                else:
                    raise FileNotFoundError(f"Configuration file not found: {self.config_path}")
            
            with open(self.config_path, 'r') as f:
                self.config = json.load(f)
                
            # 验证配置
            is_valid, error = ConfigValidator.validate_config(self.config)
            if not is_valid:
                logging.error(f"Invalid configuration: {error}")
                # 尝试从备份恢复
                backup_path = self.config_path + ".bak"
                if os.path.exists(backup_path):
                    logging.warning("Attempting to load from backup configuration")
                    with open(backup_path, 'r') as f:
                        self.config = json.load(f)
                    is_valid, error = ConfigValidator.validate_config(self.config)
                    if not is_valid:
                        raise ValueError(f"Backup config also invalid: {error}")
                else:
                    raise ValueError(f"Invalid configuration: {error}")
                    
            return True, None
        except Exception as e:
            logging.error(f"Failed to load config: {e}")
            self.config = {"plcs": []}
            return False, str(e)
    
    def get_config(self):
        """获取当前配置"""
        return self.config
    
    def validate_config(self, config):
        """验证配置是否有效"""
        return ConfigValidator.validate_config(config)
    
    def save_config(self, new_config):
        """保存配置文件"""
        try:
            # 验证配置
            is_valid, error = self.validate_config(new_config)
            if not is_valid:
                return False, f"Invalid configuration: {error}"
            
            # 备份旧配置
            backup_path = self.config_path + ".bak"
            if os.path.exists(self.config_path):
                with open(self.config_path, 'r') as src, open(backup_path, 'w') as dst:
                    dst.write(src.read())
            
            # 保存新配置
            with open(self.config_path, 'w') as f:
                json.dump(new_config, f, indent=2)
            
            self.config = new_config
            return True, None
        except Exception as e:
            logging.error(f"Failed to save config: {e}")
            return False, str(e)
    
    def reload_config(self):
        """重新加载配置"""
        return self.load_config()