# -*- coding: utf-8 -*-

# Copyright (c) 2021 - 2022 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a bar widget showing just icons.
"""

import contextlib

from PyQt6.QtCore import pyqtSignal, pyqtSlot, Qt, QCoreApplication
from PyQt6.QtGui import QColor, QIcon, QCursor, QPalette
from PyQt6.QtWidgets import QWidget, QBoxLayout, QWIDGETSIZE_MAX, QMenu

from EricWidgets.EricApplication import ericApp

from .EricClickableLabel import EricClickableLabel

import UI.PixmapCache


class EricIconBar(QWidget):
    """
    Class implementing a bar widget showing just icons.
    
    @signal currentChanged(index) emitted to indicate a change of the current
        index
    @signal currentClicked(index) emitted to indicate, that the current icon
        was clicked
    """
    BarSizes = {
        # tuples with (icon size, border size, translated size string)
        "xs": (
            16, 1,
            QCoreApplication.translate("EricIconBar", "extra small")
        ),
        "sm": (
            22, 1,
            QCoreApplication.translate("EricIconBar", "small")
        ),
        "md": (
            32, 2,
            QCoreApplication.translate("EricIconBar", "medium")
        ),
        "lg": (
            48, 2,
            QCoreApplication.translate("EricIconBar", "large")
        ),
        "xl": (
            64, 3,
            QCoreApplication.translate("EricIconBar", "extra large")
        ),
        "xxl": (
            96, 3,
            QCoreApplication.translate("EricIconBar", "very large")
        ),
    }
    DefaultBarSize = "md"
    
    MoreLabelAspect = 36 / 96
    
    MenuStyleSheetTemplate = (
        "QMenu {{ background-color: {0}; "
        "selection-background-color: {1}; "
        "border: 1px solid; }}"
    )
    WidgetStyleSheetTemplate = "QWidget {{ background-color: {0}; }}"
    LabelStyleSheetTemplate = "QLabel {{ background-color: {0}; }}"
    
    currentChanged = pyqtSignal(int)
    currentClicked = pyqtSignal(int)
    
    def __init__(self, orientation=Qt.Orientation.Horizontal,
                 barSize=DefaultBarSize, parent=None):
        """
        Constructor
        
        @param orientation orientation for the widget
        @type Qt.Orientation
        @param barSize size category for the bar (one of 'xs', 'sm', 'md',
            'lg', 'xl', 'xxl')
        @type str
        @param parent reference to the parent widget (defaults to None)
        @type QWidget (optional)
        """
        super().__init__(parent)
        
        try:
            self.__barSize, self.__borderSize = (
                EricIconBar.BarSizes[barSize][:2])
            self.__barSizeKey = barSize
        except KeyError:
            self.__barSize, self.__borderSize = (
                EricIconBar.BarSizes[EricIconBar.DefaultBarSize][:2])
        self.__fixedHeightWidth = (
            self.__barSize + 2 * self.__borderSize
        )
        self.__minimumHeightWidth = int(
            self.__barSize * self.MoreLabelAspect) + 2 * self.__borderSize
        
        # set initial values
        self.__color = QColor("#008800")
        self.__orientation = Qt.Orientation.Horizontal
        self.__currentIndex = -1
        self.__icons = []
        
        # initialize with horizontal layout and change later if needed
        self.setAttribute(Qt.WidgetAttribute.WA_StyledBackground, True)
        self.setFixedHeight(self.__fixedHeightWidth)
        self.setMinimumWidth(self.__minimumHeightWidth)
        
        self.__layout = QBoxLayout(QBoxLayout.Direction.LeftToRight)
        self.__layout.setContentsMargins(
            self.__borderSize, self.__borderSize,
            self.__borderSize, self.__borderSize)
        
        self.__layout.addStretch()
        
        self.setLayout(self.__layout)
        
        if orientation != self.__orientation:
            self.setOrientation(orientation)
        
        self.setColor(self.__color)
        
        self.__createAndAddMoreLabel()
        
        self.__adjustIconLabels()
    
    def setOrientation(self, orientation):
        """
        Public method to set the widget orientation.
        
        @param orientation orientation to be set
        @type Qt.Orientation
        """
        # reset list widget size constraints
        self.setFixedSize(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX)
        
        # remove the 'More' icon
        itm = self.__layout.takeAt(self.__layout.count() - 1)
        itm.widget().deleteLater()
        del itm
        
        if orientation == Qt.Orientation.Horizontal:
            self.setFixedHeight(self.__fixedHeightWidth)
            self.setMinimumWidth(self.__minimumHeightWidth)
            self.__layout.setDirection(QBoxLayout.Direction.LeftToRight)
        elif orientation == Qt.Orientation.Vertical:
            self.setFixedWidth(self.__fixedHeightWidth)
            self.setMinimumHeight(self.__minimumHeightWidth)
            self.__layout.setDirection(QBoxLayout.Direction.TopToBottom)
        
        self.__orientation = orientation
        
        self.__createAndAddMoreLabel()
        
        self.__adjustIconLabels()
    
    def orientation(self):
        """
        Public method to get the orientation of the widget.
        
        @return orientation of the widget
        @rtype Qt.Orientation
        """
        return self.__orientation
    
    def setBarSize(self, barSize):
        """
        Public method to set the icon bar size.
        
        @param barSize size category for the bar (one of 'xs', 'sm', 'md',
            'lg', 'xl', 'xxl')
        @type str
        """
        # remove the 'More' icon
        itm = self.__layout.takeAt(self.__layout.count() - 1)
        itm.widget().deleteLater()
        del itm
        
        self.__barSize, self.__borderSize = (
            EricIconBar.BarSizes[barSize][:2])
        self.__barSizeKey = barSize
        self.__fixedHeightWidth = (
            self.__barSize + 2 * self.__borderSize
        )
        self.__minimumHeightWidth = int(
            self.__barSize * self.MoreLabelAspect) + 2 * self.__borderSize
        
        if self.__orientation == Qt.Orientation.Horizontal:
            self.setFixedHeight(self.__fixedHeightWidth)
            self.setMinimumWidth(self.__minimumHeightWidth)
        elif self.__orientation == Qt.Orientation.Vertical:
            self.setFixedWidth(self.__fixedHeightWidth)
            self.setMinimumHeight(self.__minimumHeightWidth)
        
        self.__layout.setContentsMargins(
            self.__borderSize, self.__borderSize,
            self.__borderSize, self.__borderSize)
        
        for index, icon in enumerate(self.__icons):
            iconLabel = self.__layout.itemAt(index)
            if iconLabel:
                widget = iconLabel.widget()
                widget.setFixedSize(self.__barSize, self.__barSize)
                widget.setPixmap(
                    icon.pixmap(self.__barSize, self.__barSize))
        
        self.__createAndAddMoreLabel()
        
        self.__adjustIconLabels()
    
    def barSize(self):
        """
        Public method to get the icon bar size.
        
        @return barSize size category for the bar (one of 'xs', 'sm', 'md',
            'lg', 'xl', 'xxl')
        @rtype str
        """
        return self.__barSizeKey
    
    def setColor(self, color):
        """
        Public method to set the color of the widget.
        
        @param color color of the widget
        @type QColor
        """
        self.__color = color
        self.__highlightColor = color.darker()
        
        self.setStyleSheet(
            EricIconBar.WidgetStyleSheetTemplate.format(color.name()))
        
        label = self.__layout.itemAt(self.__currentIndex)
        if label:
            label.widget().setStyleSheet(
                EricIconBar.LabelStyleSheetTemplate
                .format(self.__highlightColor.name())
            )
    
    def color(self):
        """
        Public method to return the current color.
        
        @return current color
        @rtype QColor
        """
        return self.__color
    
    def __createIcon(self, icon, label=""):
        """
        Private method to creat an icon label.
        
        @param icon reference to the icon
        @type QIcon
        @param label label text to be shown as a tooltip (defaults to "")
        @type str (optional)
        @return created and connected label
        @rtype EricClickableLabel
        """
        iconLabel = EricClickableLabel(self)
        iconLabel.setFixedSize(self.__barSize, self.__barSize)
        iconLabel.setAlignment(Qt.AlignmentFlag.AlignCenter)
        iconLabel.setPixmap(icon.pixmap(self.__barSize, self.__barSize))
        if label:
            iconLabel.setToolTip(label)
        
        iconLabel.clicked.connect(lambda: self.__iconClicked(iconLabel))
        
        return iconLabel
    
    def __createAndAddMoreLabel(self):
        """
        Private method to create the label to be shown for too many icons.
        """
        self.__moreLabel = EricClickableLabel(self)
        self.__moreLabel.setAlignment(Qt.AlignmentFlag.AlignCenter)
        if self.__orientation == Qt.Orientation.Horizontal:
            self.__moreLabel.setFixedSize(
                int(self.__barSize * self.MoreLabelAspect), self.__barSize)
            self.__moreLabel.setPixmap(
                UI.PixmapCache.getIcon("sbDotsH96").pixmap(
                    int(self.__barSize * self.MoreLabelAspect), self.__barSize
                )
            )
        else:
            self.__moreLabel.setFixedSize(
                self.__barSize, int(self.__barSize * self.MoreLabelAspect))
            self.__moreLabel.setPixmap(
                UI.PixmapCache.getIcon("sbDotsV96").pixmap(
                    self.__barSize, int(self.__barSize * self.MoreLabelAspect)
                )
            )
        
        self.__layout.addWidget(self.__moreLabel)
        
        self.__moreLabel.clicked.connect(self.__moreLabelClicked)
    
    def addIcon(self, icon, label=""):
        """
        Public method to add an icon to the bar.
        
        @param icon reference to the icon
        @type QIcon
        @param label label text to be shown as a tooltip (defaults to "")
        @type str (optional)
        """
        # the stretch item is always the last one
        self.insertIcon(self.count(), icon, label=label)
    
    def insertIcon(self, index, icon, label=""):
        """
        Public method to insert an icon into the bar.
        
        @param index position to insert the icon at
        @type int
        @param icon reference to the icon
        @type QIcon
        @param label label text to be shown as a tooltip (defaults to "")
        @type str (optional)
        """
        iconLabel = self.__createIcon(icon, label=label)
        self.__layout.insertWidget(index, iconLabel)
        self.__icons.insert(index, QIcon(icon))
        
        if self.__currentIndex < 0:
            self.setCurrentIndex(index)
        elif index <= self.__currentIndex:
            self.setCurrentIndex(self.__currentIndex + 1)
        
        self.__adjustIconLabels()
    
    def removeIcon(self, index):
        """
        Public method to remove an icon from the bar.
        
        @param index index of the icon to be removed
        @type int
        """
        label = self.__layout.itemAt(index)
        if label:
            with contextlib.suppress(IndexError):
                del self.__icons[index]
            itm = self.__layout.takeAt(index)
            itm.widget().deleteLater()
            del itm
            
            if index == self.__currentIndex:
                self.setCurrentIndex(index)
            elif index < self.__currentIndex:
                self.setCurrentIndex(self.__currentIndex - 1)
            
            self.__adjustIconLabels()
    
    @pyqtSlot()
    def __iconClicked(self, label):
        """
        Private slot to handle an icon been clicked.
        
        @param label reference to the clicked label
        @type EricClickableLabel
        """
        index = self.__layout.indexOf(label)
        if index >= 0:
            if index == self.__currentIndex:
                self.currentClicked.emit(self.__currentIndex)
            else:
                self.setCurrentIndex(index)
    
    def setCurrentIndex(self, index):
        """
        Public method to set the current index.
        
        @param index current index to be set
        @type int
        """
        if index >= self.count():
            index = -1
        
        if index != self.__currentIndex and index >= 0:
            # reset style of previous current icon
            oldLabel = self.__layout.itemAt(self.__currentIndex)
            if oldLabel:
                widget = oldLabel.widget()
                if widget is not None:
                    widget.setStyleSheet("")
            
            # set style of new current icon
            newLabel = self.__layout.itemAt(index)
            if newLabel:
                newLabel.widget().setStyleSheet(
                    EricIconBar.LabelStyleSheetTemplate
                    .format(self.__highlightColor.name())
                )
            
            self.__currentIndex = index
            self.currentChanged.emit(self.__currentIndex)
    
    def currentIndex(self):
        """
        Public method to get the current index.
        
        @return current index
        @rtype int
        """
        return self.__currentIndex
    
    def count(self):
        """
        Public method to get the number of icon labels.
        
        @return number of icon labels
        @rtype int
        """
        return len(self.__icons)
    
    def wheelEvent(self, evt):
        """
        Protected method to handle a wheel event.
        
        @param evt reference to the wheel event
        @type QWheelEvent
        """
        delta = evt.angleDelta().y()
        if delta > 0:
            self.previousIcon()
        else:
            self.nextIcon()
    
    @pyqtSlot()
    def previousIcon(self):
        """
        Public slot to set the icon before the current one.
        """
        index = self.__currentIndex - 1
        if index < 0:
            # wrap around
            index = self.count() - 1
        
        self.setCurrentIndex(index)
    
    @pyqtSlot()
    def nextIcon(self):
        """
        Public slot to set the icon after the current one.
        """
        index = self.__currentIndex + 1
        if index == self.count():
            # wrap around
            index = 0
        
        self.setCurrentIndex(index)
    
    @pyqtSlot()
    def __moreLabelClicked(self):
        """
        Private slot to handle a click onto the 'More' label.
        """
        menu = QMenu(self)
        baseColor = ericApp().palette().color(
            QPalette.ColorRole.Base)
        highlightColor = ericApp().palette().color(
            QPalette.ColorRole.Highlight)
        menu.setStyleSheet(
            EricIconBar.MenuStyleSheetTemplate.format(
                baseColor.name(), highlightColor.name()))
        
        for index in range(self.count()):
            iconLabel = self.__layout.itemAt(index)
            if iconLabel:
                widget = iconLabel.widget()
                if not widget.isVisible():
                    act = menu.addAction(widget.toolTip())
                    act.setData(index)
        
        selectedAction = menu.exec(QCursor.pos())
        if selectedAction is not None:
            index = selectedAction.data()
            if index >= 0:
                if index == self.__currentIndex:
                    self.currentClicked.emit(self.__currentIndex)
                else:
                    self.setCurrentIndex(index)
    
    def resizeEvent(self, evt):
        """
        Protected method to handle resizing of the icon bar.
        
        @param evt reference to the event object
        @type QResizeEvent
        """
        self.__adjustIconLabels()
    
    def __adjustIconLabels(self):
        """
        Private method to adjust the visibility of the icon labels.
        """
        size = (
            self.width()
            if self.orientation() == Qt.Orientation.Horizontal else
            self.height()
        ) - 2 * self.__borderSize
        
        iconsSize = self.count() * self.__barSize
        
        if size < iconsSize:
            self.__moreLabel.show()
            iconsSize += int(self.__barSize * self.MoreLabelAspect)
            for index in range(self.count() - 1, -1, -1):
                iconLabel = self.__layout.itemAt(index)
                if iconLabel:
                    if size < iconsSize:
                        iconLabel.widget().hide()
                        iconsSize -= self.__barSize
                    else:
                        iconLabel.widget().show()
        else:
            self.__moreLabel.hide()
            for index in range(self.count()):
                iconLabel = self.__layout.itemAt(index)
                if iconLabel:
                    iconLabel.widget().show()
