# coding:utf-8
from typing import Dict, Union

from PyQt5.QtCore import Qt, pyqtSignal, QRect
from PyQt5.QtGui import QPixmap, QPainter, QColor, QIcon
from PyQt5.QtWidgets import QWidget, QVBoxLayout, QSizePolicy

from ...common.config import isDarkTheme
from ...common.font import setFont
from ...common.style_sheet import themeColor
from ...common.icon import drawIcon, FluentIconBase, toQIcon
from ...common.icon import FluentIcon as FIF
from ...common.router import qrouter
from ...common.style_sheet import FluentStyleSheet
from ..widgets.scroll_area import SingleDirectionScrollArea
from .navigation_widget import NavigationPushButton, NavigationWidget
from .navigation_panel import RouteKeyError, NavigationItemPosition


class NavigationBarPushButton(NavigationPushButton):
    """ Navigation bar push button """

    def __init__(self, icon: Union[str, QIcon, FIF], text: str, isSelectable: bool, selectedIcon=None, parent=None):
        super().__init__(icon, text, isSelectable, parent)
        self._selectedIcon = selectedIcon
        self.setFixedSize(64, 58)
        setFont(self, 11)

    def selectedIcon(self):
        if self._selectedIcon:
            return toQIcon(self._selectedIcon)

        return QIcon()

    def setSelectedIcon(self, icon: Union[str, QIcon, FIF]):
        self._selectedIcon = icon
        self.update()

    def paintEvent(self, e):
        painter = QPainter(self)
        painter.setRenderHints(QPainter.Antialiasing |
                               QPainter.TextAntialiasing | QPainter.SmoothPixmapTransform)
        painter.setPen(Qt.NoPen)

        # draw background
        if self.isSelected:
            painter.setBrush(QColor(255, 255, 255, 42) if isDarkTheme() else Qt.white)
            painter.drawRoundedRect(self.rect(), 5, 5)

            # draw indicator
            painter.setBrush(themeColor())
            if not self.isPressed:
                painter.drawRoundedRect(0, 16, 4, 24, 2, 2)
            else:
                painter.drawRoundedRect(0, 19, 4, 18, 2, 2)
        elif self.isPressed or self.isEnter:
            c = 255 if isDarkTheme() else 0
            alpha = 9 if self.isEnter else 6
            painter.setBrush(QColor(c, c, c, alpha))
            painter.drawRoundedRect(self.rect(), 5, 5)

        # draw icon
        if (self.isPressed or not self.isEnter) and not self.isSelected:
            painter.setOpacity(0.6)
        if not self.isEnabled():
            painter.setOpacity(0.4)

        rect = QRect(22, 13, 20, 20)
        selectedIcon = self._selectedIcon or self._icon

        if isinstance(selectedIcon, FluentIconBase) and self.isSelected:
            selectedIcon.render(painter, rect, fill=themeColor().name())
        elif self.isSelected:
            drawIcon(selectedIcon, painter, rect)
        else:
            drawIcon(self._icon, painter, rect)

        # draw text
        if self.isSelected:
            painter.setPen(themeColor())
        else:
            painter.setPen(Qt.white if isDarkTheme() else Qt.black)

        painter.setFont(self.font())
        rect = QRect(0, 32, self.width(), 26)
        painter.drawText(rect, Qt.AlignCenter, self.text())


class NavigationBar(QWidget):

    def __init__(self, parent=None):
        super().__init__(parent=parent)

        self.scrollArea = SingleDirectionScrollArea(self)
        self.scrollWidget = QWidget()

        self.vBoxLayout = QVBoxLayout(self)
        self.topLayout = QVBoxLayout()
        self.bottomLayout = QVBoxLayout()
        self.scrollLayout = QVBoxLayout(self.scrollWidget)

        self.items = {}   # type: Dict[str, NavigationWidget]
        self.history = qrouter

        self.__initWidget()

    def __initWidget(self):
        self.resize(48, self.height())
        self.setAttribute(Qt.WA_StyledBackground)
        self.window().installEventFilter(self)

        self.scrollArea.setHorizontalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.scrollArea.setVerticalScrollBarPolicy(Qt.ScrollBarAlwaysOff)
        self.scrollArea.setWidget(self.scrollWidget)
        self.scrollArea.setWidgetResizable(True)

        self.scrollWidget.setObjectName('scrollWidget')
        FluentStyleSheet.NAVIGATION_INTERFACE.apply(self)
        FluentStyleSheet.NAVIGATION_INTERFACE.apply(self.scrollWidget)
        self.__initLayout()

    def __initLayout(self):
        self.vBoxLayout.setContentsMargins(0, 5, 0, 5)
        self.topLayout.setContentsMargins(4, 0, 4, 0)
        self.bottomLayout.setContentsMargins(4, 0, 4, 0)
        self.scrollLayout.setContentsMargins(4, 0, 4, 0)
        self.vBoxLayout.setSpacing(4)
        self.topLayout.setSpacing(4)
        self.bottomLayout.setSpacing(4)
        self.scrollLayout.setSpacing(4)

        self.vBoxLayout.addLayout(self.topLayout, 0)
        self.vBoxLayout.addWidget(self.scrollArea)
        self.vBoxLayout.addLayout(self.bottomLayout, 0)

        self.vBoxLayout.setAlignment(Qt.AlignTop)
        self.topLayout.setAlignment(Qt.AlignTop)
        self.scrollLayout.setAlignment(Qt.AlignTop)
        self.bottomLayout.setAlignment(Qt.AlignBottom)

    def widget(self, routeKey: str):
        if routeKey not in self.items:
            raise RouteKeyError(f"`{routeKey}` is illegal.")

        return self.items[routeKey]

    def addItem(self, routeKey: str, icon: Union[str, QIcon, FluentIconBase], text: str ,onClick=None,
                selectable=True, selectedIcon=None, position=NavigationItemPosition.TOP):
        """ add navigation item

        Parameters
        ----------
        routeKey: str
            the unique name of item

        icon: str | QIcon | FluentIconBase
            the icon of navigation item

        text: str
            the text of navigation item

        onClick: callable
            the slot connected to item clicked signal

        selectable: bool
            whether the item is selectable

        selectedIcon: str | QIcon | FluentIconBase
            the icon of navigation item in selected state

        position: NavigationItemPosition
            where the button is added
        """
        return self.insertItem(-1, routeKey, icon, text, onClick, selectable, selectedIcon, position)

    def addWidget(self, routeKey: str, widget: NavigationWidget, onClick=None, position=NavigationItemPosition.TOP):
        """ add custom widget

        Parameters
        ----------
        routeKey: str
            the unique name of item

        widget: NavigationWidget
            the custom widget to be added

        onClick: callable
            the slot connected to item clicked signal

        position: NavigationItemPosition
            where the button is added
        """
        self.insertWidget(-1, routeKey, widget, onClick, position)

    def insertItem(self, index: int, routeKey: str, icon: Union[str, QIcon, FluentIconBase], text: str, onClick=None,
                   selectable=True, selectedIcon=None, position=NavigationItemPosition.TOP):
        """ insert navigation tree item

        Parameters
        ----------
        index: int
            the insert position of parent widget

        routeKey: str
            the unique name of item

        icon: str | QIcon | FluentIconBase
            the icon of navigation item

        text: str
            the text of navigation item

        onClick: callable
            the slot connected to item clicked signal

        selectable: bool
            whether the item is selectable

        selectedIcon: str | QIcon | FluentIconBase
            the icon of navigation item in selected state

        position: NavigationItemPosition
            where the button is added
        """
        if routeKey in self.items:
            return

        w = NavigationBarPushButton(icon, text, selectable, selectedIcon, self)
        self.insertWidget(index, routeKey, w, onClick, position)
        return w

    def insertWidget(self, index: int, routeKey: str, widget: NavigationWidget, onClick=None,
                     position=NavigationItemPosition.TOP):
        """ insert custom widget

        Parameters
        ----------
        index: int
            insert position

        routeKey: str
            the unique name of item

        widget: NavigationWidget
            the custom widget to be added

        onClick: callable
            the slot connected to item clicked signal

        position: NavigationItemPosition
            where the button is added
        """
        if routeKey in self.items:
            return

        self._registerWidget(routeKey, widget, onClick)
        self._insertWidgetToLayout(index, widget, position)

    def _registerWidget(self, routeKey: str, widget: NavigationWidget, onClick):
        """ register widget """
        widget.clicked.connect(self._onWidgetClicked)

        if onClick is not None:
            widget.clicked.connect(onClick)

        widget.setProperty('routeKey', routeKey)
        self.items[routeKey] = widget

    def _insertWidgetToLayout(self, index: int, widget: NavigationWidget, position: NavigationItemPosition):
        """ insert widget to layout """
        if position == NavigationItemPosition.TOP:
            widget.setParent(self)
            self.topLayout.insertWidget(index, widget, 0, Qt.AlignTop | Qt.AlignHCenter)
        elif position == NavigationItemPosition.SCROLL:
            widget.setParent(self.scrollWidget)
            self.scrollLayout.insertWidget(index, widget, 0, Qt.AlignTop | Qt.AlignHCenter)
        else:
            widget.setParent(self)
            self.bottomLayout.insertWidget(index, widget, 0, Qt.AlignBottom | Qt.AlignHCenter)

        widget.show()

    def removeWidget(self, routeKey: str):
        """ remove widget

        Parameters
        ----------
        routeKey: str
            the unique name of item
        """
        if routeKey not in self.items:
            return

        widget = self.items.pop(routeKey)
        widget.deleteLater()
        self.history.remove(routeKey)

    def setCurrentItem(self, routeKey: str):
        """ set current selected item

        Parameters
        ----------
        routeKey: str
            the unique name of item
        """
        if routeKey not in self.items:
            return

        for k, widget in self.items.items():
            widget.setSelected(k == routeKey)

    def _onWidgetClicked(self):
        widget = self.sender()  # type: NavigationWidget
        if widget.isSelectable:
            self.setCurrentItem(widget.property('routeKey'))
