use crate::codec::SerialConfig;

use tokio_serial::{SerialPortBuilderExt, SerialStream};
use tokio_modbus::{
    client::rtu,
    client::Context,
    slave::Slave,
    prelude::*,
};

pub (crate) struct ModbusClient {
    ctx: Context
}

impl ModbusClient {

    pub fn new(serial_config: SerialConfig) -> Self {
        let port_name = String::from_utf8(serial_config.port).unwrap();
        let parity = match serial_config.parity {
            0x00 => tokio_serial::Parity::None,
            0x01 => tokio_serial::Parity::Odd,
            0x02 => tokio_serial::Parity::Even,
            _ => tokio_serial::Parity::None
        };

        let stopbits = match serial_config.stopbits {
            0x01 => tokio_serial::StopBits::One,
            0x02 => tokio_serial::StopBits::Two,
            _ => tokio_serial::StopBits::One
        };

        let builder = tokio_serial::new(port_name, serial_config.baudrate)
            .data_bits(tokio_serial::DataBits::Eight)
            .stop_bits(stopbits)
            .parity(parity)
            .timeout(std::time::Duration::from_millis(serial_config.timeout as u64));

        // 2. 建立串口连接
        let port = builder.open_native_async().unwrap();

        // 3. 创建Modbus RTU客户端 (0.16.1新API)
        let slave_id = Slave(0x01); // 从站地址
        let ctx = rtu::attach_slave(port, slave_id);

        Self {
            ctx
        }
    }
}