from UM.Qt.ListModel import ListModel
from PyQt5.QtCore import pyqtSignal, pyqtProperty, pyqtSlot
from UM.Scene.Iterator.DepthFirstIterator import DepthFirstIterator
from UM.Scene.SceneNode import SceneNode
from UM.Scene.Selection import Selection
from UM.Logger import Logger
from UM.Application import Application


class BuildPlateModel(ListModel):
    maxBuildPlateChanged = pyqtSignal()
    activeBuildPlateChanged = pyqtSignal()
    selectionChanged = pyqtSignal()

    def __init__(self):
        super().__init__()
        Application.getInstance().getController().getScene().sceneChanged.connect(self.updateMaxBuildPlate)  # it may be a bit inefficient when changing a lot simultaneously
        Application.getInstance().getController().getScene().sceneChanged.connect(self._updateSelectedObjectBuildPlateNumbers)
        Selection.selectionChanged.connect(self._updateSelectedObjectBuildPlateNumbers)

        self._max_build_plate = 1  # default
        self._active_build_plate = -1
        self._selection_build_plates = []

    @pyqtSlot(int)
    def setActiveBuildPlate(self, nr):
        if nr == self._active_build_plate:
            return
        Logger.log("d", "Select build plate: %s" % nr)
        self._active_build_plate = nr

        self.activeBuildPlateChanged.emit()

    @pyqtProperty(int, notify = activeBuildPlateChanged)
    def activeBuildPlate(self):
        return self._active_build_plate

    ##  Return the highest build plate number
    @pyqtProperty(int, notify = maxBuildPlateChanged)
    def maxBuildPlate(self):
        return self._max_build_plate

    def updateMaxBuildPlate(self, source):
        if not issubclass(type(source), SceneNode):
            return
        max_build_plate = self._calcMaxBuildPlate()
        changed = False
        if max_build_plate != self._max_build_plate:
            self._max_build_plate = max_build_plate
            changed = True
        if changed:
            self.maxBuildPlateChanged.emit()
            build_plates = [{"name": "Build Plate %d" % (i + 1), "buildPlateNumber": i} for i in range(self._max_build_plate + 1)]
            self.setItems(build_plates)
            self.itemsChanged.emit()

    def _calcMaxBuildPlate(self):
        max_build_plate = 0
        for node in DepthFirstIterator(Application.getInstance().getController().getScene().getRoot()):
            if node.callDecoration("isSliceable"):
                build_plate_number = node.callDecoration("getBuildPlateNumber")
                max_build_plate = max(build_plate_number, max_build_plate)
        return max_build_plate

    @staticmethod
    def createBuildPlateModel():
        return BuildPlateModel()

    def _updateSelectedObjectBuildPlateNumbers(self, *args):
        result = set()
        for node in Selection.getAllSelectedObjects():
            result.add(node.callDecoration("getBuildPlateNumber"))
        self._selection_build_plates = list(result)
        self.selectionChanged.emit()

    @pyqtProperty("QVariantList", notify = selectionChanged)
    def selectionBuildPlates(self):
        return self._selection_build_plates