# -*- coding: utf-8 -*-
"""称重终端驱动 —— 化工/树脂行业称重仪参数化适配。

多数称重仪表走串口（连续输出 / 命令应答）或 Modbus TCP；
本驱动作为模板封装：优先按配置走 Modbus（复用 ModbusDriver），
若配置指定 `mode: serial` 则走串口协议（需现场协议文档，由子类定制）。
"""
from __future__ import annotations

from typing import Dict, List, Optional

from point_dict.loader import Point
from .base import Driver, SampleValue
from .modbus_driver import ModbusDriver


class WeighingDriver(Driver):
    """称重终端只读采集驱动（参数化适配）。"""

    protocol = "weighing"

    def __init__(self, config: Optional[dict] = None):
        super().__init__(config)
        self.mode: str = self.config.get("mode", "modbus")  # modbus | serial
        self._delegate: Optional[Driver] = None

    def connect(self) -> None:
        if self.mode == "modbus":
            # 称重仪表普遍支持 Modbus RTU/TCP，复用 ModbusDriver 参数化实现
            self._delegate = ModbusDriver(self.config)
        else:
            raise ConnectionError(
                "称重驱动 serial 模式需要现场协议文档支持，请实现子类或改用 modbus 模式"
            )
        self._delegate.connect()

    def read_points(self, points: List[Point]) -> Dict[str, SampleValue]:
        if self._delegate is None:
            raise ConnectionError("称重驱动未连接，请先 connect()")
        return self._delegate.read_points(points)

    def close(self) -> None:
        if self._delegate is not None:
            self._delegate.close()
            self._delegate = None