#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2019, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),
more specifically its template base application.

Laborejo2 is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import logging; logging.info("import {}".format(__file__))


#Third Party
from PyQt5 import QtCore, QtGui, QtWidgets, QtOpenGL


#Template Modules
from template.helper import onlyOne

#Our Modules
from .constantsAndConfigs import constantsAndConfigs
from .scorescene import GuiScore
import engine.api as api

class ScoreView(QtWidgets.QGraphicsView):
    def __init__(self, mainWindow):
        super().__init__()        
        self.mainWindow = mainWindow    

        self.scoreScene = GuiScore(parentView=self)
        self.setScene(self.scoreScene)

        viewport = QtOpenGL.QGLWidget(QtOpenGL.QGLFormat(QtOpenGL.QGL.SampleBuffers))
        viewport.format().setSwapInterval(0) #disable VSync.
        viewport.setAutoFillBackground(False)

        viewport = QtWidgets.QOpenGLWidget()
        #These special parameters should not matter. Run with the default.
        #viewportFormat = QtGui.QSurfaceFormat()
        #viewportFormat.setSwapInterval(0) #disable VSync
        #viewportFormat.setSamples(2**8)
        #viewportFormat.setDefaultFormat(viewportFormat)
        #viewport.setFormat(viewportFormat)
        self.setViewport(viewport)

        self.setAlignment(QtCore.Qt.AlignLeft|QtCore.Qt.AlignTop)

        #self.setDragMode(QtWidgets.QGraphicsView.RubberBandDrag)
        self.setDragMode(QtWidgets.QGraphicsView.NoDrag)

        api.callbacks.setCursor.append(self.centerOnCursor) #returns a dict
        api.callbacks.updateBlockTrack.append(self.updateMode) # We need  this after every update because the track is redrawn after each update and we don't know what to show

        style = """
        QScrollBar:horizontal {
            border: 1px solid black;
        }

        QScrollBar::handle:horizontal {
            background: #00b2b2;
        }

        QScrollBar:vertical {
            border: 1px solid black;
        }

        QScrollBar::handle:vertical {
            background: #00b2b2;
        }
        """
        self.setStyleSheet(style)

    def wheelEvent(self, event):
        if QtWidgets.QApplication.keyboardModifiers() in (QtCore.Qt.ControlModifier, QtCore.Qt.ControlModifier|QtCore.Qt.ShiftModifier): #a workaround for a qt bug. see score.wheelEvent docstring.        
            event.ignore() #do not send to scene, but tell the mainWindow to use it.
        else:            
            super().wheelEvent(event) #send to scene

    def centerOnCursor(self, cursorExportObject):
        if (not constantsAndConfigs.followPlayhead) or not api.playbackStatus():
            self.centerOn(self.scoreScene.cursor.scenePos())
            #discard cursorExportObject.

    def toggleFollowPlayhead(self):
        constantsAndConfigs.followPlayhead = not constantsAndConfigs.followPlayhead
        self.mainWindow.ui.actionFollow_Playhead.setChecked(constantsAndConfigs.followPlayhead)
        #we register a callback in self init that checks constantsAndConfigs.followPlayhead

    def stretchXCoordinates(self, factor):
        self.scoreScene.stretchXCoordinates(factor)
        self.centerOnCursor(None)
        
    def zoom(self, scaleFactor:float):
        """Scale factor is absolute"""        
        self.resetTransform()                
        self.scale(scaleFactor, scaleFactor)

    def toggleNoteheadsRectangles(self):
        """Each notehead/rectangle toggles its own state.
        That means each GuiChord gets toggled individually.
        Both versions, notehead and rectangle, exist all the time, so
        nothing gets recreated, just visibility toggled.

        Rectangles/Noteheads are their own realm and do not conflict
        with CC View toggle or other view modes."""

        constantsAndConfigs.noteHeadMode = not constantsAndConfigs.noteHeadMode
        self.mainWindow.ui.actionToggle_Notehead_Rectangles.setChecked(not constantsAndConfigs.noteHeadMode)
        self.scoreScene.toggleNoteheadsRectangles()

    def _switchToRectanglesForFunction(self, function):
        """some actions like actionVelocityMore, actionVelocityLess,
        actionDurationModMore, actionDurationModLess,
        actionReset_Velocity_Duration_Mod can be called even if
        not in rectangle mode. We switch into rectangle mode for them
        so the user can see the changes."""
        if not self.mainWindow.ui.actionToggle_Notehead_Rectangles.isChecked():
            self.toggleNoteheadsRectangles()
        function() #this is most likely an api function

    def mode(self):
        """Return the current edit mode as string.
        Mostly needed for structures blockAt and other
        functions that need to find the target of a mouse click."""
        if self.mainWindow.ui.actionCC_Mode.isChecked():
            return "cc"
        elif self.mainWindow.ui.actionNotation_Mode.isChecked():
            return "notation"
        elif self.mainWindow.ui.actionBlock_Mode.isChecked():
            return "block"
        else:
            raise ValueError("Edit Mode unknown")

    def resizeEvent(self, event):
        self.scoreScene.grid.reactToresizeEventOrZoom()
        super().resizeEvent(event)

    def changeGridRhythm(self):
        GridRhytmEdit(mainWindow=self.mainWindow) #handles everything.

    def updateMode(self, *args):
        """Switch through different views for editing:
            notes and item edit
            CC curves
            note-blocks only (without items)

        Which mode is active depends entirely on the state of qt checkboxes in the menu.
        The menu-actions call this function. We make sure and double sure that there is never
        ambiguity in the menu or in the program mode itself.

        If you want to check for the mode in any place of the program use self.mode().
        It is just above this function.

        Therefore: Every mode switch is only allowed through this function.
        There is no direct setting of the mode. You should call the menu
        action directly if you want to programatically change the mode.
        """

        assert onlyOne((self.mainWindow.ui.actionCC_Mode.isChecked(), self.mainWindow.ui.actionNotation_Mode.isChecked(), self.mainWindow.ui.actionBlock_Mode.isChecked()))

        if self.mainWindow.ui.actionData_Editor.isChecked():
            #no modechange in the track editor
            return

        if self.mainWindow.ui.actionCC_Mode.isChecked():
            self.mainWindow.menuActionDatabase.ccEditMode()
            self.mainWindow.menuActionDatabase.writeProtection(True)
            self.scoreScene.updateMode("cc")
            self.mainWindow.menuActionDatabase.loadToolbarContext("cc")

        elif self.mainWindow.ui.actionNotation_Mode.isChecked():
            self.mainWindow.menuActionDatabase.noteEditMode()
            self.mainWindow.menuActionDatabase.writeProtection(False)
            self.scoreScene.updateMode("notation")
            self.mainWindow.menuActionDatabase.loadToolbarContext("notation")

        elif self.mainWindow.ui.actionBlock_Mode.isChecked():
            self.mainWindow.menuActionDatabase.noteEditMode()
            self.mainWindow.menuActionDatabase.writeProtection(True)
            self.scoreScene.updateMode("block")
            self.mainWindow.menuActionDatabase.loadToolbarContext("block")
        else:
            raise ValueError("Edit Mode unknown")