import sys
import time
import numpy as np
from matplotlib.backends.qt_compat import QtCore, QtWidgets

from matplotlib.backends.backend_qt5agg import (FigureCanvas, NavigationToolbar2QT as NavigationToolbar)

from matplotlib.figure import Figure

from protocol.Celery.MBTCPMaster import app as MBTCPMApp
from celery.result import AsyncResult
from model.ProjectModel.VarManage import ModbusVarManage
from utils import Globals

class ActualTrend(QtWidgets.QMainWindow):
    def __init__(self, parent=None, varName = None):
        super(ActualTrend, self).__init__(parent)

        self.varName = varName
        self.protocolManage = Globals.getValue('protocolManage')

        _main = QtWidgets.QWidget()
        self.setCentralWidget(_main)
        layout = QtWidgets.QVBoxLayout(_main)

        dynamic_canvas = FigureCanvas(Figure(figsize=(5, 3)))
        layout.addWidget(dynamic_canvas)
        self.addToolBar(QtCore.Qt.BottomToolBarArea,
            NavigationToolbar(dynamic_canvas, self))

        self.x = [] # 建立空的x轴数组和y轴数组
        self.y = []
        self.maxPoints = 200
        self._dynamic_ax = dynamic_canvas.figure.subplots()
        self._timer = dynamic_canvas.new_timer(
          500, [(self._update_canvas, (), {})])
        self._timer.start()

    def _update_canvas(self):
        # 防止canvas已被销毁时报错
        if not hasattr(self, '_dynamic_ax') or not hasattr(self._dynamic_ax, 'figure') or not hasattr(self._dynamic_ax.figure, 'canvas'):
            return
        varName = self.varName
        if not varName or not self.protocolManage:
            return
        # 获取实时值
        yValue = self.protocolManage.readVariableValue(varName)
        acttime = time.strftime('%H:%M:%S', time.localtime(time.time()))
        if yValue is not None:
            self.x.append(acttime)
            self.y.append(yValue)
            # 只保留最新maxPoints个点
            if len(self.x) > self.maxPoints:
                self.x = self.x[-self.maxPoints:]
                self.y = self.y[-self.maxPoints:]
        self._dynamic_ax.clear()
        pos_list = np.arange(len(self.x))
        self._dynamic_ax.set_xticks(pos_list)
        # 限制最多显示16个主刻度，自动旋转，字体更大更明显
        import matplotlib.ticker as ticker
        max_xticks = 12
        if len(self.x) > max_xticks:
            step = max(1, len(self.x) // max_xticks)
            display_labels = [label if i % step == 0 else '' for i, label in enumerate(self.x)]
        else:
            display_labels = self.x
        self._dynamic_ax.set_xticklabels(display_labels, rotation=30, fontsize=13, fontweight='bold')
        self._dynamic_ax.plot(pos_list, self.y, 'bo-', linewidth=2)
        if self.y:
            minY = min(self.y) - 5
            maxY = max(self.y) + 5
            self._dynamic_ax.set_ylim(minY, maxY)
            from matplotlib.ticker import MaxNLocator
            self._dynamic_ax.yaxis.set_major_locator(MaxNLocator(nbins=12, prune=None))
        self._dynamic_ax.figure.canvas.draw()

    def closeEvent(self, event):
        # 停止定时器，防止回调访问已销毁的canvas
        if hasattr(self, '_timer'):
            self._timer.stop()
        super().closeEvent(event)
        self.hide()

    def showEvent(self, event):
        self._timer.start()
        
if __name__ == "__main__":
    qapp = QtWidgets.QApplication(sys.argv)
    app = ActualTrend()
    app.show()
    qapp.exec_()