"""
novelWriter – Custom Widget: Novel Selector
===========================================

File History:
Created: 2022-11-17 [2.0] NovelSelector

This file is a part of novelWriter
Copyright (C) 2022 Veronica Berglyd Olsen and novelWriter contributors

This program 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 <https://www.gnu.org/licenses/>.
"""
from __future__ import annotations

import logging

from PyQt6.QtCore import pyqtSignal, pyqtSlot
from PyQt6.QtGui import QPalette
from PyQt6.QtWidgets import QComboBox, QWidget

from novelwriter import SHARED
from novelwriter.constants import nwLabels
from novelwriter.enum import nwItemClass

logger = logging.getLogger(__name__)


class NovelSelector(QComboBox):

    novelSelectionChanged = pyqtSignal(str)

    def __init__(self, parent: QWidget) -> None:
        super().__init__(parent=parent)
        self._blockSignal = False
        self._firstHandle = None
        self._includeAll = False
        self._listFormat = None
        self.currentIndexChanged.connect(self._indexChanged)
        self.updateTheme()
        return

    ##
    #  Properties
    ##

    @property
    def handle(self) -> str | None:
        """Return the selected handle, if any."""
        if tHandle := self.currentData():
            return tHandle
        return None

    @property
    def firstHandle(self) -> str | None:
        return self._firstHandle

    ##
    #  Methods
    ##

    def setHandle(self, tHandle: str | None, blockSignal: bool = True) -> None:
        """Set the currently selected handle."""
        if (index := self.findData(tHandle) if tHandle else (self.count() - 1)) >= 0:
            self._blockSignal = blockSignal
            self.setCurrentIndex(index)
            self._blockSignal = False
        return

    def setIncludeAll(self, value: bool) -> None:
        """Set flag to add an "All Novel Folders" option."""
        self._includeAll = value
        return

    def setListFormat(self, value: str | None) -> None:
        """Set a format string for the list entries."""
        if value is None or "{0}" in value:
            self._listFormat = value
        return

    def updateTheme(self) -> None:
        """Update theme colours."""
        palette = self.palette()
        palette.setBrush(QPalette.ColorGroup.Disabled, QPalette.ColorRole.Text, palette.text())
        self.setPalette(palette)
        self.refreshNovelList()
        return

    ##
    #  Public Slots
    ##

    @pyqtSlot()
    def refreshNovelList(self) -> None:
        """Rebuild the list of novel items."""
        cHandle = self.currentData()

        self._blockSignal = True
        self._firstHandle = None
        self.clear()

        icon = SHARED.theme.getIcon(nwLabels.CLASS_ICON[nwItemClass.NOVEL], "blue")
        for tHandle, nwItem in SHARED.project.tree.iterRoots(nwItemClass.NOVEL):
            if self._listFormat:
                name = self._listFormat.format(nwItem.itemName)
                self.addItem(name, tHandle)
            else:
                name = nwItem.itemName
                self.addItem(icon, nwItem.itemName, tHandle)
            if self._firstHandle is None:
                self._firstHandle = tHandle

        if self._includeAll:
            self.insertSeparator(self.count())
            self.addItem(icon, self.tr("All Novel Folders"), "")

        self.setHandle(cHandle)
        self.setEnabled(self.count() > 1)
        self._blockSignal = False

        return

    ##
    #  Private Slots
    ##

    @pyqtSlot(int)
    def _indexChanged(self, index: int) -> None:
        """Re-emit the change of selection signal, unless blocked."""
        if not self._blockSignal:
            self.novelSelectionChanged.emit(self.currentData())
        return