"""
novelWriter – Custom Widget: Progress Circle
============================================

File History:
Created: 2023-06-07 [2.1b1]

This file is a part of novelWriter
Copyright 2018–2024, Veronica Berglyd Olsen

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

from math import ceil

from PyQt5.QtGui import QBrush, QColor, QPaintEvent, QPainter, QPen
from PyQt5.QtCore import QRect, Qt
from PyQt5.QtWidgets import QProgressBar, QSizePolicy, QWidget

from novelwriter.types import QtAlignCenter


class NProgressCircle(QProgressBar):
    """Extension: Circular Progress Widget

    A custom widget that paints a circular progress indicator instead of
    a straight bar. It is also possible to set custom text for iṫ.
    """

    __slots__ = (
        "_text", "_point", "_dRect", "_cRect", "_dPen", "_dBrush",
        "_cPen", "_bPen", "_tColor"
    )

    def __init__(self, parent: QWidget, size: int, point: int) -> None:
        super().__init__(parent=parent)
        self._text = None
        self._point = point
        self._dRect = QRect(0, 0, size, size)
        self._cRect = QRect(point, point, size - 2*point, size - 2*point)
        self._dPen = QPen(Qt.transparent)
        self._dBrush = QBrush(Qt.transparent)
        self.setColours(
            track=self.palette().alternateBase().color(),
            bar=self.palette().highlight().color(),
            text=self.palette().text().color()
        )
        self.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)
        self.setFixedWidth(size)
        self.setFixedHeight(size)
        return

    def setColours(self, back: QColor | None = None, track: QColor | None = None,
                   bar: QColor | None = None, text: QColor | None = None) -> None:
        """Set the colours of the widget."""
        if isinstance(back, QColor):
            self._dPen = QPen(back)
            self._dBrush = QBrush(back)
        if isinstance(bar, QColor):
            self._cPen = QPen(QBrush(bar), self._point, Qt.SolidLine, Qt.RoundCap)
        if isinstance(track, QColor):
            self._bPen = QPen(QBrush(track), self._point, Qt.SolidLine, Qt.RoundCap)
        if isinstance(text, QColor):
            self._tColor = text
        return

    def setCentreText(self, text: str | None) -> None:
        """Replace the progress text with a custom string."""
        self._text = text
        self.setValue(self.value())  # Triggers a redraw
        return

    def paintEvent(self, event: QPaintEvent) -> None:
        """Custom painter for the progress bar."""
        progress = 100.0*self.value()/self.maximum()
        angle = ceil(16*3.6*progress)
        painter = QPainter(self)
        painter.setRenderHint(QPainter.Antialiasing, True)
        painter.setPen(self._dPen)
        painter.setBrush(self._dBrush)
        painter.drawEllipse(self._dRect)
        painter.setPen(self._bPen)
        painter.drawArc(self._cRect, 0, 360*16)
        painter.setPen(self._cPen)
        painter.drawArc(self._cRect, 90*16, -angle)
        painter.setPen(self._tColor)
        painter.drawText(self._cRect, QtAlignCenter, self._text or f"{progress:.1f} %")
        return

# END Class NProgressCircle