import json
import os

class Config:
    def __init__(self, config_file="config.json"):
        self.config_file = config_file
        self.default_config = {
            # LoRa通信配置
            "lora": {
                "address": "0x1234",
                "frequency": 433,
                "bandwidth": 125,
                "spreading_factor": 7,
                "coding_rate": 5,
                "encryption_key": "default_key"
            },
            
            # 上位机配置
            "master": {
                "lora_address": "0x5678",
                "protocol": "modbus"
            },
            
            # 总线配置
            "bus": {
                "sensor": {
                    "port": "/dev/ttyUSB0",
                    "baudrate": 9600,
                    "devices": []
                },
                "actuator": {
                    "port": "/dev/ttyUSB1",
                    "baudrate": 9600,
                    "devices": []
                }
            },
            
            # 日志配置
            "log": {
                "level": "INFO",
                "file_path": "logs/pig_house.log",
                "max_size": "1KB",  # 减小日志文件大小
                "backup_count": 1,  # 只保留一个备份文件
                "report_errors": True,  # 是否上报错误
                "terminate_on_report_failure": True  # 上报失败时是否终止程序
            },
            
            # 系统参数
            "system": {
                "heartbeat_interval": 60,  # 心跳包间隔(秒)
                "data_collection_interval": 300,  # 数据采集间隔(秒)
                "command_timeout": 10,  # 命令超时时间(秒)
                "retry_count": 3,  # 重试次数
                "error_handling": "retry"
            },
            
            # 设备配置
            "devices": [
                {
                    "id": "temp_01",
                    "type": "temperature",
                    "address": "0x01",
                    "bus": "sensor",
                    "unit": "celsius"
                },
                {
                    "id": "humidity_01", 
                    "type": "humidity",
                    "address": "0x02",
                    "bus": "sensor",
                    "unit": "%"
                },
                {
                    "id": "feed_01",
                    "type": "feed_port",
                    "address": "0x10",
                    "bus": "actuator"
                },
                {
                    "id": "water_01",
                    "type": "water_valve",
                    "address": "0x11", 
                    "bus": "actuator"
                }
            ]
        }
        self.config = {}
        self.load_config()

    def load_config(self):
        """加载配置文件"""
        if os.path.exists(self.config_file):
            try:
                with open(self.config_file, "r", encoding="utf-8") as file:
                    config_data = json.load(file)
                    # 合并默认配置和文件配置
                    self.config = self._merge_dict(self.default_config, config_data)
            except Exception as e:
                print(f"加载配置文件出错: {e}，使用默认配置")
                self.config = self.default_config
        else:
            print("配置文件不存在，使用默认配置")
            self.config = self.default_config
            self.save_config()

    def save_config(self):
        """保存配置到文件"""
        try:
            # 确保目录存在
            os.makedirs(os.path.dirname(self.config_file), exist_ok=True)
        except:
            pass
            
        with open(self.config_file, "w", encoding="utf-8") as file:
            json.dump(self.config, file, indent=4, ensure_ascii=False)

    def get(self, key_path, default=None):
        """根据路径获取配置项，例如: get('lora.address')"""
        keys = key_path.split('.')
        value = self.config
        try:
            for key in keys:
                value = value[key]
            return value
        except (KeyError, TypeError):
            return default

    def set(self, key_path, value):
        """根据路径设置配置项"""
        keys = key_path.split('.')
        config_ref = self.config
        for key in keys[:-1]:
            if key not in config_ref:
                config_ref[key] = {}
            config_ref = config_ref[key]
        config_ref[keys[-1]] = value

    def _merge_dict(self, default, override):
        """合并两个字典，保留默认值"""
        merged = default.copy()
        for key, value in override.items():
            if key in merged and isinstance(merged[key], dict) and isinstance(value, dict):
                merged[key] = self._merge_dict(merged[key], value)
            else:
                merged[key] = value
        return merged

    # 便捷访问方法
    def lora_config(self):
        return self.config.get('lora', {})

    def master_config(self):
        return self.config.get('master', {})

    def bus_config(self):
        return self.config.get('bus', {})

    def log_config(self):
        return self.config.get('log', {})

    def system_config(self):
        return self.config.get('system', {})

    def devices_config(self):
        return self.config.get('devices', [])