from krita import DockWidget
from PyQt5.QtWidgets import QWidget, QDialog, QVBoxLayout, QHBoxLayout, QLabel, QLineEdit, QComboBox, QCheckBox, QPushButton

DOCKER_TITLE = 'Page Slicer'

class PageSlicer(DockWidget):

    def __init__(self):
        super().__init__()
        self.setWindowTitle(DOCKER_TITLE)
        widget = QWidget()
        layout = QVBoxLayout()
        widget.setLayout(layout)

        layout.addSpacing(10)
        layout.addWidget(QLabel('Slice up an image into segments using page guides.'))

        # Thresholds for ignoring segments. Defaults to 100px in both dimensions.
        # limitModes = ['<', '>']
        self.widthInput = QLineEdit('100')
        # self.widthLimitMode = QComboBox()
        # self.widthLimitMode.addItems(limitModes)
        self.heightInput = QLineEdit('100')
        # self.heightLimitMode = QComboBox()
        # self.heightLimitMode.addItems(limitModes)
        layout.addWidget(QLabel('Segment-Ignore Thresholds:'))
        row1 = QHBoxLayout()
        row1.addWidget(QLabel('Width <'))
        # row1.addWidget(self.widthLimitMode)
        row1.addWidget(self.widthInput)
        row1.addWidget(QLabel('px'))
        layout.addLayout(row1)
        row2 = QHBoxLayout()
        row2.addWidget(QLabel('Height <'))
        # row2.addWidget(self.heightLimitMode)
        row2.addWidget(self.heightInput)
        row2.addWidget(QLabel('px'))
        layout.addLayout(row2)

        # Use image bounds or not
        self.useImageBoundsCheck = QCheckBox('Use Image Bounds')
        self.useImageBoundsCheck.setChecked(False)
        layout.addWidget(self.useImageBoundsCheck)

        # Button!
        layout.addSpacing(20)
        goButton = QPushButton("Slice")
        goButton.setIcon( Krita.instance().icon('animation_play') )
        layout.addWidget(goButton)

        # Add a stretch to prevent the rest of the content from stretching.
        layout.addStretch()

        # Add widget to the docker.
        self.setWidget(widget)

        # Hook up the action to the button.
        goButton.clicked.connect( self.slicePage )


    # notifies when views are added or removed
    # 'pass' means do not do anything
    def canvasChanged(self, canvas):
        pass


    ##########
    # Slots
    ##########

    # Actually slices the page.
    def slicePage(self, e):

        # Get the current layer.
        doc = Krita.instance().activeDocument()
        root = doc.rootNode()
        layer = doc.activeNode()
        if layer.type() != 'paintlayer':
            dialog = QDialog()
            dialog.setWindowTitle("Paint Layer Required")
            layout = QVBoxLayout()
            layout.addWidget(QLabel('Page slicer only works on paint layers. Please select one.'))
            dialog.setLayout(layout)
            dialog.exec_()
            return

        # Get horizontal and vertical points.
        # Horizontal guides provide the Vertical y-axis points and vice versa.
        vPoints = doc.horizontalGuides()
        hPoints = doc.verticalGuides()

        # Add the edges of the image for segment calculation, if needed.
        useImageBounds = self.useImageBoundsCheck.checkState()
        if useImageBounds:
            vPoints.insert(0, 0)
            vPoints.append(doc.height())
            hPoints.insert(0, 0)
            hPoints.append(doc.width())

        # Sanitize points. Guide values are floats, and may contain unexpected
        # extra fractional values.
        vPoints = [round(v) for v in vPoints]
        vPoints.sort()
        hPoints = [round(h) for h in hPoints]
        hPoints.sort()

        # Check that there are enough vertical and horizontal points.
        # When using image bounds there must be at least 1 guide (V or H).
        # When not using image bounds, there must be at least 4 guides (2V, 2H).
        imageBoundsLimitFail = True if len(vPoints) + len(hPoints) < 5 else False
        nonImageBoundsLimitFail = True if len(vPoints) < 2 or len(hPoints) < 2 else False
        if (useImageBounds and imageBoundsLimitFail) or nonImageBoundsLimitFail:
            dialog = QDialog()
            dialog.setWindowTitle("Insufficient Guides!")
            layout = QVBoxLayout()
            if useImageBounds:
                layout.addWidget(QLabel('Have at least 1 horizontal or vertical guide.'))
            else:
                layout.addWidget(QLabel('Have at least 2 horizontal and 2 vertical guides.'))
            dialog.setLayout(layout)
            dialog.exec_()
            return

        # Find segments, row by row.
        startV = vPoints.pop(0)
        startH = hPoints.pop(0)
        prevV = startV
        count = 1
        heightLimit = int(self.heightInput.text())
        widthLimit = int(self.widthInput.text())
        for v in vPoints:
            segHeight = v - prevV
            if segHeight >= heightLimit:
                prevH = startH
                for h in hPoints:
                    segWidth = h - prevH
                    if segWidth >= widthLimit:
                        # Copy image data to new layer.
                        segmentData = layer.pixelData(prevH, prevV, segWidth, segHeight)
                        newLayer = doc.createNode('seg' + str(count), 'paintLayer')
                        newLayer.setPixelData(segmentData, prevH, prevV, segWidth, segHeight)
                        root.addChildNode(newLayer, None)
                        count += 1
                    prevH = h
            prevV = v