text: # -*- coding: utf-8 -*-
  from ..Qt import QtCore, QtGui, QtWidgets
  from ..graphicsItems.GraphicsObject import GraphicsObject
  from .. import functions as fn
  from .Terminal import *
  from collections import OrderedDict
  from ..debug import *
  import numpy as np
  import warnings
  
  translate = QtCore.QCoreApplication.translate
  
  def strDict(d):
      return dict([(str(k), v) for k, v in d.items()])
  
  class Node(QtCore.QObject):
      """
      Node represents the basic processing unit of a flowchart. 
      A Node subclass implements at least:
      
      1) A list of input / ouptut terminals and their properties
      2) a process() function which takes the names of input terminals as keyword arguments and returns a dict with the names of output terminals as keys.
  
      A flowchart thus consists of multiple instances of Node subclasses, each of which is connected
      to other by wires between their terminals. A flowchart is, itself, also a special subclass of Node.
      This allows Nodes within the flowchart to connect to the input/output nodes of the flowchart itself.
  
      Optionally, a node class can implement the ctrlWidget() method, which must return a QWidget (usually containing other widgets) that will be displayed in the flowchart control panel. Some nodes implement fairly complex control widgets, but most nodes follow a simple form-like pattern: a list of parameter names and a single value (represented as spin box, check box, etc..) for each parameter. To make this easier, the CtrlNode subclass allows you to instead define a simple data structure that CtrlNode will use to automatically generate the control widget.     """
      
      sigOutputChanged = QtCore.Signal(object)   # self
      sigClosed = QtCore.Signal(object)
      sigRenamed = QtCore.Signal(object, object)
      sigTerminalRenamed = QtCore.Signal(object, object)  # term, oldName
      sigTerminalAdded = QtCore.Signal(object, object)  # self, term
      sigTerminalRemoved = QtCore.Signal(object, object)  # self, term
  
      
      def __init__(self, name, terminals=None, allowAddInput=False, allowAddOutput=False, allowRemove=True):
          """
          ==============  ============================================================
          **Arguments:**
          name            The name of this specific node instance. It can be any 
                          string, but must be unique within a flowchart. Usually,
                          we simply let the flowchart decide on a name when calling
                          Flowchart.addNode(...)
          terminals       Dict-of-dicts specifying the terminals present on this Node.
                          Terminal specifications look like::
                          
                              'inputTerminalName': {'io': 'in'}
                              'outputTerminalName': {'io': 'out'} 
                              
                          There are a number of optional parameters for terminals:
                          multi, pos, renamable, removable, multiable, bypass. See
                          the Terminal class for more information.
          allowAddInput   bool; whether the user is allowed to add inputs by the
                          context menu.
          allowAddOutput  bool; whether the user is allowed to add outputs by the
                          context menu.
          allowRemove     bool; whether the user is allowed to remove this node by the
                          context menu.
          ==============  ============================================================  
          
          """
          QtCore.QObject.__init__(self)
          self._name = name
          self._bypass = False
          self.bypassButton = None  ## this will be set by the flowchart ctrl widget..
          self._graphicsItem = None
          self.terminals = OrderedDict()
          self._inputs = OrderedDict()
          self._outputs = OrderedDict()
          self._allowAddInput = allowAddInput   ## flags to allow the user to add/remove terminals
          self._allowAddOutput = allowAddOutput
          self._allowRemove = allowRemove
          
          self.exception = None
          if terminals is None:
              return
          for name, opts in terminals.items():
              self.addTerminal(name, **opts)
  
          
      def nextTerminalName(self, name):
          """Return an unused terminal name"""
          name2 = name
          i = 1
          while name2 in self.terminals:
              name2 = "%s.%d" % (name, i)
              i += 1
          return name2
          
      def addInput(self, name="Input", **args):
          """Add a new input terminal to this Node with the given name. Extra
          keyword arguments are passed to Terminal.__init__.
          
          This is a convenience function that just calls addTerminal(io='in', ...)"""
          #print "Node.addInput called."
          return self.addTerminal(name, io='in', **args)
          
      def addOutput(self, name="Output", **args):
          """Add a new output terminal to this Node with the given name. Extra
          keyword arguments are passed to Terminal.__init__.
          
          This is a convenience function that just calls addTerminal(io='out', ...)"""
          return self.addTerminal(name, io='out', **args)
          
      def removeTerminal(self, term):
          """Remove the specified terminal from this Node. May specify either the 
          terminal's name or the terminal itself.
          
          Causes sigTerminalRemoved to be emitted."""
          if isinstance(term, Terminal):
              name = term.name()
          else:
              name = term
              term = self.terminals[name]
          
          #print "remove", name
          #term.disconnectAll()
          term.close()
          del self.terminals[name]
          if name in self._inputs:
              del self._inputs[name]
          if name in self._outputs:
              del self._outputs[name]
          self.graphicsItem().updateTerminals()
          self.sigTerminalRemoved.emit(self, term)
          
          
      def terminalRenamed(self, term, oldName):
          """Called after a terminal has been renamed        
          
          Causes sigTerminalRenamed to be emitted."""
          newName = term.name()
          for d in [self.terminals, self._inputs, self._outputs]:
              if oldName not in d:
                  continue
              d[newName] = d[oldName]
              del d[oldName]
              
          self.graphicsItem().updateTerminals()
          self.sigTerminalRenamed.emit(term, oldName)
          
      def addTerminal(self, name, **opts):
          """Add a new terminal to this Node with the given name. Extra
          keyword arguments are passed to Terminal.__init__.
                  
          Causes sigTerminalAdded to be emitted."""
          name = self.nextTerminalName(name)
          term = Terminal(self, name, **opts)
          self.terminals[name] = term
          if term.isInput():
              self._inputs[name] = term
          elif term.isOutput():
              self._outputs[name] = term
          self.graphicsItem().updateTerminals()
          self.sigTerminalAdded.emit(self, term)
          return term
  
          
      def inputs(self):
          """Return dict of all input terminals.
          Warning: do not modify."""
          return self._inputs
          
      def outputs(self):
          """Return dict of all output terminals.
          Warning: do not modify."""
          return self._outputs
          
      def process(self, **kargs):
          """Process data through this node. This method is called any time the flowchart 
          wants the node to process data. It will be called with one keyword argument
          corresponding to each input terminal, and must return a dict mapping the name
          of each output terminal to its new value.
          
          This method is also called with a 'display' keyword argument, which indicates
          whether the node should update its display (if it implements any) while processing
          this data. This is primarily used to disable expensive display operations
          during batch processing.
          """
          return {}
      
      def graphicsItem(self):
          """Return the GraphicsItem for this node. Subclasses may re-implement
          this method to customize their appearance in the flowchart."""
          if self._graphicsItem is None:
              self._graphicsItem = NodeGraphicsItem(self)
          return self._graphicsItem
      
      ## this is just bad planning. Causes too many bugs.
      def __getattr__(self, attr):
          """Return the terminal with the given name"""
          warnings.warn(
              "Use of note.terminalName is deprecated, use node['terminalName'] instead"
              "Will be removed from 0.13.0",
              DeprecationWarning, stacklevel=2
          )
          
          if attr not in self.terminals:
              raise AttributeError(attr)
          else:
              import traceback
              traceback.print_stack()
              print("Warning: use of node.terminalName is deprecated; use node['terminalName'] instead.")
              return self.terminals[attr]
              
      def __getitem__(self, item):
          #return getattr(self, item)
          """Return the terminal with the given name"""
          if item not in self.terminals:
              raise KeyError(item)
          else:
              return self.terminals[item]
              
      def name(self):
          """Return the name of this node."""
          return self._name
  
      def rename(self, name):
          """Rename this node. This will cause sigRenamed to be emitted."""
          oldName = self._name
          self._name = name
          #self.emit(QtCore.SIGNAL('renamed'), self, oldName)
          self.sigRenamed.emit(self, oldName)
  
      def dependentNodes(self):
          """Return the list of nodes which provide direct input to this node"""
          nodes = set()
          for t in self.inputs().values():
              nodes |= set([i.node() for i in t.inputTerminals()])
          return nodes
          #return set([t.inputTerminals().node() for t in self.listInputs().values()])
          
      def __repr__(self):
          return "<Node %s @%x>" % (self.name(), id(self))
          
      def ctrlWidget(self):
          """Return this Node's control widget. 
          
          By default, Nodes have no control widget. Subclasses may reimplement this 
          method to provide a custom widget. This method is called by Flowcharts
          when they are constructing their Node list."""
          return None
  
      def bypass(self, byp):
          """Set whether this node should be bypassed.
          
          When bypassed, a Node's process() method is never called. In some cases,
          data is automatically copied directly from specific input nodes to 
          output nodes instead (see the bypass argument to Terminal.__init__). 
          This is usually called when the user disables a node from the flowchart 
          control panel.
          """
          self._bypass = byp
          if self.bypassButton is not None:
              self.bypassButton.setChecked(byp)
          self.update()
          
      def isBypassed(self):
          """Return True if this Node is currently bypassed."""
          return self._bypass
  
      def setInput(self, **args):
          """Set the values on input terminals. For most nodes, this will happen automatically through Terminal.inputChanged.
          This is normally only used for nodes with no connected inputs."""
          changed = False
          for k, v in args.items():
              term = self._inputs[k]
              oldVal = term.value()
              if not fn.eq(oldVal, v):
                  changed = True
              term.setValue(v, process=False)
          if changed and '_updatesHandled_' not in args:
              self.update()
          
      def inputValues(self):
          """Return a dict of all input values currently assigned to this node."""
          vals = {}
          for n, t in self.inputs().items():
              vals[n] = t.value()
          return vals
              
      def outputValues(self):
          """Return a dict of all output values currently generated by this node."""
          vals = {}
          for n, t in self.outputs().items():
              vals[n] = t.value()
          return vals
              
      def connected(self, localTerm, remoteTerm):
          """Called whenever one of this node's terminals is connected elsewhere."""
          pass
      
      def disconnected(self, localTerm, remoteTerm):
          """Called whenever one of this node's terminals is disconnected from another."""
          pass 
      
      def update(self, signal=True):
          """Collect all input values, attempt to process new output values, and propagate downstream.
          Subclasses should call update() whenever thir internal state has changed
          (such as when the user interacts with the Node's control widget). Update
          is automatically called when the inputs to the node are changed.
          """
          vals = self.inputValues()
          #print "  inputs:", vals
          try:
              if self.isBypassed():
                  out = self.processBypassed(vals)
              else:
                  out = self.process(**strDict(vals))
              #print "  output:", out
              if out is not None:
                  if signal:
                      self.setOutput(**out)
                  else:
                      self.setOutputNoSignal(**out)
              for n,t in self.inputs().items():
                  t.setValueAcceptable(True)
              self.clearException()
          except:
              #printExc( "Exception while processing %s:" % self.name())
              for n,t in self.outputs().items():
                  t.setValue(None)
              self.setException(sys.exc_info())
              
              if signal:
                  #self.emit(QtCore.SIGNAL('outputChanged'), self)  ## triggers flowchart to propagate new data
                  self.sigOutputChanged.emit(self)  ## triggers flowchart to propagate new data
  
      def processBypassed(self, args):
          """Called when the flowchart would normally call Node.process, but this node is currently bypassed.
          The default implementation looks for output terminals with a bypass connection and returns the
          corresponding values. Most Node subclasses will _not_ need to reimplement this method."""
          result = {}
          for term in list(self.outputs().values()):
              byp = term.bypassValue()
              if byp is None:
                  result[term.name()] = None
              else:
                  result[term.name()] = args.get(byp, None)
          return result
  
      def setOutput(self, **vals):
          self.setOutputNoSignal(**vals)
          #self.emit(QtCore.SIGNAL('outputChanged'), self)  ## triggers flowchart to propagate new data
          self.sigOutputChanged.emit(self)  ## triggers flowchart to propagate new data
  
      def setOutputNoSignal(self, **vals):
          for k, v in vals.items():
              term = self.outputs()[k]
              term.setValue(v)
              #targets = term.connections()
              #for t in targets:  ## propagate downstream
                  #if t is term:
                      #continue
                  #t.inputChanged(term)
              term.setValueAcceptable(True)
  
      def setException(self, exc):
          self.exception = exc
          self.recolor()
          
      def clearException(self):
          self.setException(None)
          
      def recolor(self):
          if self.exception is None:
              self.graphicsItem().setPen(QtGui.QPen(QtGui.QColor(0, 0, 0)))
          else:
              self.graphicsItem().setPen(QtGui.QPen(QtGui.QColor(150, 0, 0), 3))
  
      def saveState(self):
          """Return a dictionary representing the current state of this node
          (excluding input / output values). This is used for saving/reloading
          flowcharts. The default implementation returns this Node's position,
          bypass state, and information about each of its terminals. 
          
          Subclasses may want to extend this method, adding extra keys to the returned
          dict."""
          pos = self.graphicsItem().pos()
          state = {'pos': (pos.x(), pos.y()), 'bypass': self.isBypassed()}
          termsEditable = self._allowAddInput | self._allowAddOutput
          for term in list(self._inputs.values()) + list(self._outputs.values()):
              termsEditable |= term._renamable | term._removable | term._multiable
          if termsEditable:
              state['terminals'] = self.saveTerminals()
          return state
          
      def restoreState(self, state):
          """Restore the state of this node from a structure previously generated
          by saveState(). """
          pos = state.get('pos', (0,0))
          self.graphicsItem().setPos(*pos)
          self.bypass(state.get('bypass', False))
          if 'terminals' in state:
              self.restoreTerminals(state['terminals'])
  
      def saveTerminals(self):
          terms = OrderedDict()
          for n, t in self.terminals.items():
              terms[n] = (t.saveState())
          return terms
          
      def restoreTerminals(self, state):
          for name in list(self.terminals.keys()):
              if name not in state:
                  self.removeTerminal(name)
          for name, opts in state.items():
              if name in self.terminals:
                  term = self[name]
                  term.setOpts(**opts)
                  continue
              try:
                  opts = strDict(opts)
                  self.addTerminal(name, **opts)
              except:
                  printExc("Error restoring terminal %s (%s):" % (str(name), str(opts)))
                  
          
      def clearTerminals(self):
          for t in self.terminals.values():
              t.close()
          self.terminals = OrderedDict()
          self._inputs = OrderedDict()
          self._outputs = OrderedDict()
          
      def close(self):
          """Cleans up after the node--removes terminals, graphicsItem, widget"""
          self.disconnectAll()
          self.clearTerminals()
          item = self.graphicsItem()
          if item.scene() is not None:
              item.scene().removeItem(item)
          self._graphicsItem = None
          w = self.ctrlWidget()
          if w is not None:
              w.setParent(None)
          #self.emit(QtCore.SIGNAL('closed'), self)
          self.sigClosed.emit(self)
              
      def disconnectAll(self):
          for t in self.terminals.values():
              t.disconnectAll()
      
  
  class TextItem(QtWidgets.QGraphicsTextItem):
      def __init__(self, text, parent, on_update):
          super().__init__(text, parent)
          self.on_update = on_update
  
      def focusOutEvent(self, ev):
          super().focusOutEvent(ev)
          if self.on_update is not None:
              self.on_update()
  
      def keyPressEvent(self, ev):
          if ev.key() == QtCore.Qt.Key_Enter or ev.key() == QtCore.Qt.Key_Return:
              if self.on_update is not None:
                  self.on_update()
                  return
          super().keyPressEvent(ev)
  
  
  #class NodeGraphicsItem(QtGui.QGraphicsItem):
  class NodeGraphicsItem(GraphicsObject):
      def __init__(self, node):
          #QtGui.QGraphicsItem.__init__(self)
          GraphicsObject.__init__(self)
          #QObjectWorkaround.__init__(self)
          
          #self.shadow = QtGui.QGraphicsDropShadowEffect()
          #self.shadow.setOffset(5,5)
          #self.shadow.setBlurRadius(10)
          #self.setGraphicsEffect(self.shadow)
          
          self.pen = fn.mkPen(0,0,0)
          self.selectPen = fn.mkPen(200,200,200,width=2)
          self.brush = fn.mkBrush(200, 200, 200, 150)
          self.hoverBrush = fn.mkBrush(200, 200, 200, 200)
          self.selectBrush = fn.mkBrush(200, 200, 255, 200)
          self.hovered = False
          
          self.node = node
          flags = self.ItemIsMovable | self.ItemIsSelectable | self.ItemIsFocusable |self.ItemSendsGeometryChanges
          #flags =  self.ItemIsFocusable |self.ItemSendsGeometryChanges
  
          self.setFlags(flags)
          self.bounds = QtCore.QRectF(0, 0, 100, 100)
          self.nameItem = TextItem(self.node.name(), self, self.labelChanged)
          self.nameItem.setDefaultTextColor(QtGui.QColor(50, 50, 50))
          self.nameItem.moveBy(self.bounds.width()/2. - self.nameItem.boundingRect().width()/2., 0)
          self.nameItem.setTextInteractionFlags(QtCore.Qt.TextEditorInteraction)
          self.updateTerminals()
          #self.setZValue(10)
  
          self.menu = None
          self.buildMenu()
          
          #self.node.sigTerminalRenamed.connect(self.updateActionMenu)
          
      #def setZValue(self, z):
          #for t, item in self.terminals.values():
              #item.setZValue(z+1)
          #GraphicsObject.setZValue(self, z)
          
      def labelChanged(self):
          newName = str(self.nameItem.toPlainText())
          if newName != self.node.name():
              self.node.rename(newName)
              
          ### re-center the label
          bounds = self.boundingRect()
          self.nameItem.setPos(bounds.width()/2. - self.nameItem.boundingRect().width()/2., 0)
  
      def setPen(self, *args, **kwargs):
          self.pen = fn.mkPen(*args, **kwargs)
          self.update()
          
      def setBrush(self, brush):
          self.brush = brush
          self.update()
          
          
      def updateTerminals(self):
          self.terminals = {}
          inp = self.node.inputs()
          out = self.node.outputs()
          
          maxNode = max(len(inp), len(out))
          titleOffset = 25
          nodeOffset = 12
          
          # calculate new height
          newHeight = titleOffset+maxNode*nodeOffset
          
          # if current height is not equal to new height, update
          if not self.bounds.height() == newHeight:
              self.bounds.setHeight(newHeight)
              self.update()
  
          # Populate inputs
          y = titleOffset
          for i, t in inp.items():
              item = t.graphicsItem()
              item.setParentItem(self)
              #item.setZValue(self.zValue()+1)
              item.setAnchor(0, y)
              self.terminals[i] = (t, item)
              y += nodeOffset
          
          # Populate inputs
          y = titleOffset
          for i, t in out.items():
              item = t.graphicsItem()
              item.setParentItem(self)
              item.setZValue(self.zValue())
              item.setAnchor(self.bounds.width(), y)
              self.terminals[i] = (t, item)
              y += nodeOffset
          
          #self.buildMenu()
          
          
      def boundingRect(self):
          return self.bounds.adjusted(-5, -5, 5, 5)
          
      def paint(self, p, *args):
          
          p.setPen(self.pen)
          if self.isSelected():
              p.setPen(self.selectPen)
              p.setBrush(self.selectBrush)
          else:
              p.setPen(self.pen)
              if self.hovered:
                  p.setBrush(self.hoverBrush)
              else:
                  p.setBrush(self.brush)
                  
          p.drawRect(self.bounds)
  
          
      def mousePressEvent(self, ev):
          ev.ignore()
  
  
      def mouseClickEvent(self, ev):
          #print "Node.mouseClickEvent called."
          if ev.button() == QtCore.Qt.LeftButton:
              ev.accept()
              #print "    ev.button: left"
              sel = self.isSelected()
              #ret = QtGui.QGraphicsItem.mousePressEvent(self, ev)
              self.setSelected(True)
              if not sel and self.isSelected():
                  #self.setBrush(QtGui.QBrush(QtGui.QColor(200, 200, 255)))
                  #self.emit(QtCore.SIGNAL('selected'))
                  #self.scene().selectionChanged.emit() ## for some reason this doesn't seem to be happening automatically
                  self.update()
              #return ret
          
          elif ev.button() == QtCore.Qt.RightButton:
              #print "    ev.button: right"
              ev.accept()
              #pos = ev.screenPos()
              self.raiseContextMenu(ev)
              #self.menu.popup(QtCore.QPoint(pos.x(), pos.y()))
              
      def mouseDragEvent(self, ev):
          #print "Node.mouseDrag"
          if ev.button() == QtCore.Qt.LeftButton:
              ev.accept()
              self.setPos(self.pos()+self.mapToParent(ev.pos())-self.mapToParent(ev.lastPos()))
          
      def hoverEvent(self, ev):
          if not ev.isExit() and ev.acceptClicks(QtCore.Qt.LeftButton):
              ev.acceptDrags(QtCore.Qt.LeftButton)
              self.hovered = True
          else:
              self.hovered = False
          self.update()
              
      def keyPressEvent(self, ev):
          if ev.key() == QtCore.Qt.Key_Delete or ev.key() == QtCore.Qt.Key_Backspace:
              ev.accept()
              if not self.node._allowRemove:
                  return
              self.node.close()
          else:
              ev.ignore()
  
      def itemChange(self, change, val):
          if change == self.ItemPositionHasChanged:
              for k, t in self.terminals.items():
                  t[1].nodeMoved()
          return GraphicsObject.itemChange(self, change, val)
              
  
      def getMenu(self):
          return self.menu
      
      def raiseContextMenu(self, ev):
          menu = self.scene().addParentContextMenus(self, self.getMenu(), ev)
          pos = ev.screenPos()
          menu.popup(QtCore.QPoint(pos.x(), pos.y()))
          
      def buildMenu(self):
          self.menu = QtGui.QMenu()
          self.menu.setTitle(translate("Context Menu", "Node"))
          a = self.menu.addAction(translate("Context Menu","Add input"), self.addInputFromMenu)
          if not self.node._allowAddInput:
              a.setEnabled(False)
          a = self.menu.addAction(translate("Context Menu", "Add output"), self.addOutputFromMenu)
          if not self.node._allowAddOutput:
              a.setEnabled(False)
          a = self.menu.addAction(translate("Context Menu", "Remove node"), self.node.close)
          if not self.node._allowRemove:
              a.setEnabled(False)
          
      def addInputFromMenu(self):  ## called when add input is clicked in context menu
          self.node.addInput(renamable=True, removable=True, multiable=True)
          
      def addOutputFromMenu(self):  ## called when add output is clicked in context menu
          self.node.addOutput(renamable=True, removable=True, multiable=False)
          
  