#!/usr/bin/env python3

from PyQt5.QtCore import (QPointF, QSize, Qt,pyqtSignal)
from PyQt5.QtWidgets import (QApplication,
 QFrame, QLabel,
 QSizePolicy, QSpinBox, QWidget)
from PyQt5.QtGui import QColor,QPainter,QFontMetricsF,QBrush,QLinearGradient,QPolygon,QPolygonF

class YPipeWidget(QWidget):
 signal_valuechanged = pyqtSignal(int,int)
 def __init__(self, leftFlow=0, rightFlow=0, maxFlow=100,
   parent=None):
 super(YPipeWidget, self).__init__(parent)

 self.leftSpinBox = QSpinBox(self)
 self.leftSpinBox.setRange(0, maxFlow)
 self.leftSpinBox.setValue(leftFlow)
 self.leftSpinBox.setSuffix(" l/s")
 self.leftSpinBox.setAlignment(Qt.AlignRight|Qt.AlignVCenter)
 self.leftSpinBox.valueChanged.connect(self.valueChanged)
 self.rightSpinBox = QSpinBox(self)
 self.rightSpinBox.setRange(0, maxFlow)
 self.rightSpinBox.setValue(rightFlow)
 self.rightSpinBox.setSuffix(" l/s")
 self.rightSpinBox.setAlignment(Qt.AlignRight|Qt.AlignVCenter)
 self.rightSpinBox.valueChanged.connect(self.valueChanged)

 self.label = QLabel(self)
 self.label.setFrameStyle(QFrame.StyledPanel|QFrame.Sunken)
 self.label.setAlignment(Qt.AlignCenter)
 fm = QFontMetricsF(self.font())
 self.label.setMinimumWidth(fm.width(" 999 l/s "))

 self.setSizePolicy(QSizePolicy(QSizePolicy.Expanding,
     QSizePolicy.Expanding))
 self.setMinimumSize(self.minimumSizeHint())
 self.valueChanged()


 def valueChanged(self):
 a = self.leftSpinBox.value()
 b = self.rightSpinBox.value()
 self.label.setText("{0} l/s".format(a + b))
 self.signal_valuechanged.emit(a,b)
 self.update()


 def values(self):
 return self.leftSpinBox.value(), self.rightSpinBox.value()


 def minimumSizeHint(self):
 return QSize(self.leftSpinBox.width() * 3,
   self.leftSpinBox.height() * 5)


 def resizeEvent(self, event=None):
 fm = QFontMetricsF(self.font())
 x = (self.width() - self.label.width()) / 2
 y = self.height() - (fm.height() * 1.5)
 self.label.move(x, y)
 y = self.height() / 60.0
 x = (self.width() / 4.0) - self.leftSpinBox.width()
 self.leftSpinBox.move(x, y)
 x = self.width() - (self.width() / 4.0)
 self.rightSpinBox.move(x, y)


 def paintEvent(self, event=None):
 LogicalSize = 100.0

 def logicalFromPhysical(length, side):
  return (length / side) * LogicalSize

 fm = QFontMetricsF(self.font())
 ymargin = ((LogicalSize / 30.0) +
   logicalFromPhysical(self.leftSpinBox.height(),
     self.height()))
 ymax = (LogicalSize -
  logicalFromPhysical(fm.height() * 2, self.height()))
 width = LogicalSize / 4.0
 cx, cy = LogicalSize / 2.0, LogicalSize / 3.0
 ax, ay = cx - (2 * width), ymargin
 bx, by = cx - width, ay
 dx, dy = cx + width, ay
 ex, ey = cx + (2 * width), ymargin
 fx, fy = cx + (width / 2), cx + (LogicalSize / 24.0)
 gx, gy = fx, ymax
 hx, hy = cx - (width / 2), ymax
 ix, iy = hx, fy

 painter = QPainter(self)
 painter.setRenderHint(QPainter.Antialiasing)
 side = min(self.width(), self.height())
 painter.setViewport((self.width() - side) / 2,
    (self.height() - side) / 2, side, side)
 painter.setWindow(0, 0, LogicalSize, LogicalSize)

 painter.setPen(Qt.NoPen)

 gradient = QLinearGradient(QPointF(0, 0),
      QPointF(0, 100))
 gradient.setColorAt(0, Qt.white)
 a = self.leftSpinBox.value()
 gradient.setColorAt(1, (Qt.red if a != 0 else Qt.white))
 painter.setBrush(QBrush(gradient))
 painter.drawPolygon(QPolygonF([QPointF(ax, ay), QPointF(bx, by), QPointF(cx, cy), QPointF(ix, iy)]))

 gradient = QLinearGradient(QPointF(0, 0), QPointF(0, 100))
 gradient.setColorAt(0, Qt.white)
 b = self.rightSpinBox.value()
 gradient.setColorAt(1, (Qt.blue if b != 0
    else Qt.white))
 painter.setBrush(QBrush(gradient))
 painter.drawPolygon(QPolygonF([QPointF(cx, cy), QPointF(dx, dy),QPointF(ex, ey),QPointF(fx, fy)]))

 if (a + b) == 0:
  color = QColor(Qt.white)
 else:
  ashare = (a / (a + b)) * 255.0
  bshare = 255.0 - ashare
  color = QColor(ashare, 0, bshare)
 gradient = QLinearGradient(QPointF(0, 0), QPointF(0, 100))
 gradient.setColorAt(0, Qt.white)
 gradient.setColorAt(1, color)
 painter.setBrush(QBrush(gradient))
 painter.drawPolygon(QPolygonF(
  [QPointF(cx, cy),QPointF(fx, fy),QPointF(gx, gy), QPointF(hx, hy),QPointF(ix, iy)]))

 painter.setPen(Qt.black)
 painter.drawPolyline(QPolygonF([QPointF(ax, ay), QPointF(ix, iy),QPointF(hx, hy)]))
 painter.drawPolyline(QPolygonF([QPointF(gx, gy), QPointF(fx, fy), QPointF(ex, ey)]))
 painter.drawPolyline(QPolygonF([QPointF(bx, by), QPointF(cx, cy), QPointF(dx, dy)]))

if __name__ == "__main__":
 import sys

 def valueChanged(a, b):
 print(a, b)

 app = QApplication(sys.argv)
 form = YPipeWidget()
 form.signal_valuechanged.connect(valueChanged)
 form.setWindowTitle("YPipe")
 form.move(0, 0)
 form.show()
 form.resize(400, 400)
 app.exec_()