from PyQt5.QtCore import QThread, pyqtSignal

class SerialWorker(QThread):
    # 1. 定义信号：声明我要广播的数据类型（这里是字符串和整数）
    data_received = pyqtSignal(str, int) 
    error_occurred = pyqtSignal(str)

    def __init__(self, port_name):
        super().__init__()
        self.port_name = port_name
        self.is_running = True

    def run(self):
        # 2. 这里就是子线程的“主循环”，所有耗时操作都在这里写
        # 警告：这里绝对不能出现 self.label.setText() 这种UI操作！
        try:
            # 模拟串口读取
            while self.is_running:
                data = "Sensor: 25.5C" 
                self.data_received.emit(data, 1024) # 3. 发射信号，携带数据
                self.msleep(100) # 使用QThread自带的sleep，不阻塞系统
        except Exception as e:
            self.error_occurred.emit(str(e))

    def stop(self):
        self.is_running = False

import sys
import serial
import serial.tools.list_ports
import numpy as np
import pyqtgraph as pg
from collections import deque
from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout, 
                             QHBoxLayout, QPushButton, QComboBox, QLabel, QTextEdit)
from PyQt5.QtCore import QThread, pyqtSignal, Qt

# ==========================================
# 1. 后端：串口工作线程 (Worker)
# ==========================================
class SerialWorker(QThread):
    """独立于UI的串口读取线程"""
    # 定义信号：(接收到的原始字符串, 解析出的浮点数值)
    data_received = pyqtSignal(str, float)
    status_msg = pyqtSignal(str)

    def __init__(self):
        super().__init__()
        self.is_running = False
        self.serial_port = None

    def configure(self, port, baudrate):
        self.port = port
        self.baudrate = baudrate

    def run(self):
        self.is_running = True
        try:
            self.serial_port = serial.Serial(self.port, self.baudrate, timeout=1)
            self.status_msg.emit(f"成功打开串口: {self.port}")
            
            while self.is_running:
                if self.serial_port.in_waiting > 0:
                    # 读取一行数据并解码
                    raw_data = self.serial_port.readline().decode('utf-8', errors='ignore').strip()
                    if raw_data:
                        # 假设下位机发送格式为 "TEMP:25.6"
                        try:
                            value = float(raw_data.split(':')[1])
                            self.data_received.emit(raw_data, value) # 发射信号给UI
                        except (IndexError, ValueError):
                            pass # 忽略解析错误的脏数据
                
                # 稍微休眠，避免死循环占满CPU（如果是事件驱动读取则不需要）
                self.msleep(10) 
                
        except Exception as e:
            self.status_msg.emit(f"串口错误: {str(e)}")
        finally:
            if self.serial_port and self.serial_port.is_open:
                self.serial_port.close()
            self.status_msg.emit("串口已关闭")

    def stop(self):
        self.is_running = False
        self.wait(2000) # 等待线程安全退出

# ==========================================
# 2. 前端：主界面 (UI)
# ==========================================
class MainWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("嵌入式工程师的串口波形上位机")
        self.resize(800, 600)

        # --- 初始化UI控件 ---
        central_widget = QWidget()
        self.setCentralWidget(central_widget)
        main_layout = QHBoxLayout(central_widget)

        # 左侧：控制面板
        left_panel = QVBoxLayout()
        self.combo_ports = QComboBox()
        self.combo_baud = QComboBox()
        self.combo_baud.addItems(["9600", "115200"])
        self.combo_baud.setCurrentText("115200")
        
        self.btn_connect = QPushButton("连接串口")
        self.btn_connect.clicked.connect(self.toggle_connection)
        
        self.text_log = QTextEdit()
        self.text_log.setReadOnly(True)

        left_panel.addWidget(QLabel("串口号:"))
        left_panel.addWidget(self.combo_ports)
        left_panel.addWidget(QLabel("波特率:"))
        left_panel.addWidget(self.combo_baud)
        left_panel.addWidget(self.btn_connect)
        left_panel.addWidget(QLabel("接收日志:"))
        left_panel.addWidget(self.text_log)
        
        # 右侧：pyqtgraph 实时波形图
        self.plot_widget = pg.PlotWidget(title="传感器实时波形")
        self.plot_widget.showGrid(x=True, y=True, alpha=0.3)
        self.plot_widget.setLabel('left', '数值')
        self.plot_widget.setLabel('bottom', '采样点')
        self.curve = self.plot_widget.plot(pen=pg.mkPen('r', width=2)) # 红色曲线
        
        # 使用双端队列限制显示点数，防止内存撑爆
        self.max_points = 200 
        self.y_data = deque(maxlen=self.max_points)
        self.x_data = deque(maxlen=self.max_points)

        main_layout.addLayout(left_panel, 1)
        main_layout.addWidget(self.plot_widget, 3)

        # --- 初始化后端Worker ---
        self.worker = SerialWorker()
        # 核心：绑定信号与槽！
        self.worker.data_received.connect(self.update_ui)
        self.worker.status_msg.connect(self.append_log)
        
        self.refresh_ports()

    def refresh_ports(self):
        """扫描可用串口"""
        self.combo_ports.clear()
        ports = serial.tools.list_ports.comports()
        for p in ports:
            self.combo_ports.addItem(p.device)

    def toggle_connection(self):
        """处理连接/断开按钮逻辑"""
        if not self.worker.isRunning():
            port = self.combo_ports.currentText()
            baud = int(self.combo_baud.currentText())
            if not port:
                self.append_log("错误: 请选择一个串口！")
                return
            
            self.worker.configure(port, baud)
            self.worker.start() # 启动子线程
            self.btn_connect.setText("断开连接")
            self.btn_connect.setStyleSheet("background-color: red; color: white;")
        else:
            self.worker.stop() # 停止子线程
            self.btn_connect.setText("连接串口")
            self.btn_connect.setStyleSheet("")

    # --- 槽函数：在主线程中安全更新UI ---
    def update_ui(self, raw_str: str, value: float):
        """接收Worker信号，更新日志和波形"""
        # 1. 更新文本日志
        self.text_log.append(raw_str)
        
        # 2. 更新波形数据
        self.y_data.append(value)
        self.x_data.append(len(self.y_data))
        
        # 3. 刷新pyqtgraph曲线 (极速)
        self.curve.setData(list(self.x_data), list(self.y_data))

    def append_log(self, msg: str):
        self.text_log.append(f"[系统] {msg}")

    def closeEvent(self, event):
        """窗口关闭时，确保子线程安全退出"""
        if self.worker.isRunning():
            self.worker.stop()
        event.accept()

# ==========================================
# 3. 程序入口
# ==========================================
if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())