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

DOCKER_TITLE = 'Bleed Generator'

class BleedGenerator(DockWidget):

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

        layout.addSpacing(10)
        layout.addWidget(QLabel('Adds bleed to the active paint layer.'))

        # Count and unit inputs. Default to 24px (2mm at 300dpi).
        self.countInput = QLineEdit('24')
        self.unitInput = QComboBox()
        self.unitInput.addItems( ['px', 'mm', 'inch'] )
        row1 = QHBoxLayout()
        row1.addWidget(QLabel('Bleed amount:'))
        row1.addWidget(self.countInput)
        row1.addWidget(self.unitInput)
        layout.addLayout(row1)

        # Option to bleed to boundaries.
        self.bleedToBoundsCheck = QCheckBox('Bleed to nearest guides/boundaries')
        self.bleedToBoundsCheck.setChecked(False)
        layout.addWidget(self.bleedToBoundsCheck)

        # Offset input i.e. how far from edge to start copying lines.
        self.offsetInput = QLineEdit('0')
        row2 = QHBoxLayout()
        row2.addWidget(QLabel('Offset (0 = use edge):'))
        row2.addWidget(self.offsetInput)
        row2.addWidget(QLabel('px'))
        layout.addLayout(row2)

        # Side selection
        self.topCheck = QCheckBox('Top')
        self.topCheck.setChecked(True)
        self.botCheck = QCheckBox('Bottom')
        self.botCheck.setChecked(True)
        self.leftCheck = QCheckBox('Left')
        self.leftCheck.setChecked(True)
        self.rightCheck = QCheckBox('Right')
        self.rightCheck.setChecked(True)
        layout.addWidget(QLabel('Sides to bleed:'))
        row3 = QHBoxLayout()
        row3.addWidget(self.topCheck)
        row3.addWidget(self.botCheck)
        row3.addWidget(self.leftCheck)
        row3.addWidget(self.rightCheck)
        layout.addLayout(row3)

        # Button!
        layout.addSpacing(20)
        goButton = QPushButton("Add Bleed")
        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.generateBleed )


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


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

    # Actually generates the bleed.
    def generateBleed(self, e):

        # Get the current layer
        self.doc = Krita.instance().activeDocument()
        self.layer = self.doc.activeNode()
        if self.layer.type() != 'paintlayer':
            dialog = QDialog()
            dialog.setWindowTitle("Paint Layer Required")
            layout = QVBoxLayout()
            layout.addWidget(QLabel('Bleed generator only works on paint layers. Please select one.'))
            dialog.setLayout(layout)
            dialog.exec_()
            return
        self.offset = round(float(self.offsetInput.text()))

        # Calculate how many lines of pixels to copy for each side
        amounts = self.calculateBleedAmounts()

        # Copy lines for selected sides.
        # Bounds are fetched each time as layer dimensions change.
        if self.topCheck.checkState():
            bds = self.layer.bounds()
            xpos = bds.left()
            ypos = bds.top() - self.offset
            len = bds.width()
            bleedline = self.layer.pixelData(xpos, ypos, len, 1)
            for c in range(1, amounts['top']+1):
                self.layer.setPixelData(bleedline, xpos, (ypos - c), len, 1)
        if self.botCheck.checkState():
            bds = self.layer.bounds()
            xpos = bds.left()
            ypos = bds.bottom() + self.offset
            len = bds.width()
            bleedline = self.layer.pixelData(xpos, ypos, len, 1)
            for c in range(1, amounts['bottom']+1):
                self.layer.setPixelData(bleedline, xpos, (ypos + c), len, 1)
        if self.leftCheck.checkState():
            bds = self.layer.bounds()
            xpos = bds.left() - self.offset
            ypos = bds.top()
            len = bds.height()
            bleedline = self.layer.pixelData(xpos, ypos, 1, len)
            for c in range(1, amounts['left']+1):
                self.layer.setPixelData(bleedline, (xpos - c), ypos, 1, len)
        if self.rightCheck.checkState():
            bds = self.layer.bounds()
            xpos = bds.right() + self.offset
            ypos = bds.top()
            len = bds.height()
            bleedline = self.layer.pixelData(xpos, ypos, 1, len)
            for c in range(1, amounts['right']+1):
                self.layer.setPixelData(bleedline, (xpos + c), ypos, 1, len)

        # Refresh the view, or the cloned pixels will not be immediately shown.
        self.doc.refreshProjection()


    def calculateBleedAmounts(self):
        amounts = {}
        if self.bleedToBoundsCheck.checkState():
            # Bleed amounts determined from boundaries.

            # Get all boundaries.
            vPoints = self.doc.horizontalGuides()
            hPoints = self.doc.verticalGuides()
            vPoints.insert(0, 0)
            vPoints.append(self.doc.height())
            vPoints.sort()
            hPoints.insert(0, 0)
            hPoints.append(self.doc.width())
            hPoints.sort()
            bds = self.layer.bounds()

            # Calculate bleed from layer's edge to next relevant boundary.
            prevV = 0
            top = bds.top()
            bottom = bds.bottom() + 1
            for v in vPoints:
                v = round(v)
                if 'top' not in amounts and v >= top:
                    amounts['top'] = top - prevV
                if 'bottom' not in amounts and v > bottom:
                    amounts['bottom'] = v - bottom
                    break
                prevV = v

            prevH = 0
            left = bds.left()
            right = bds.right() + 1
            for h in hPoints:
                h = round(h)
                if 'left' not in amounts and h >= left:
                    amounts['left'] = left - prevH
                if 'right' not in amounts and h > right:
                    amounts['right'] = h - right
                prevH = h

        else:
            # Bleed amounts based on the user's input.
            unit = self.unitInput.currentIndex()
            count = float(self.countInput.text())
            ppi = self.doc.resolution()
            if unit == 1: # mm
                count = count * (ppi / 24.5)
            if unit == 2: # inch
                count = count * ppi
            count = round(count) - self.offset
            amounts['top'] = count
            amounts['bottom'] = count
            amounts['left'] = count
            amounts['right'] = count

        return amounts