# Copyright (C) 2013 Riverbank Computing Limited.
# Copyright (C) 2022 The Qt Company Ltd.
# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

import math
import sys

from PySide6.QtCore import (QLineF, QPointF, QRandomGenerator, QRectF, QTimer,
                            Qt)
from PySide6.QtGui import (QBrush, QColor, QPainter, QPainterPath, QPixmap,
                           QPolygonF, QTransform)
from PySide6.QtWidgets import (QApplication, QGraphicsItem, QGraphicsScene,
                               QGraphicsView)

import mice_rc  # noqa: F401


def random(boundary):
    return QRandomGenerator.global_().bounded(boundary)


class Mouse(QGraphicsItem):
    PI = math.pi
    TWO_PI = 2.0 * PI

    # Create the bounding rectangle once.
    adjust = 0.5
    BOUNDING_RECT = QRectF(-20 - adjust, -22 - adjust, 40 + adjust,
            83 + adjust)

    def __init__(self):
        super().__init__()

        self.angle = 0.0
        self.speed = 0.0
        self._mouse_eye_direction = 0.0
        self.color = QColor(random(256), random(256), random(256))

        self.setTransform(QTransform().rotate(random(360 * 16)))

    @staticmethod
    def normalize_angle(angle):
        while angle < 0:
            angle += Mouse.TWO_PI
        while angle > Mouse.TWO_PI:
            angle -= Mouse.TWO_PI
        return angle

    def boundingRect(self):
        return Mouse.BOUNDING_RECT

    def shape(self):
        path = QPainterPath()
        path.addRect(-10, -20, 20, 40)
        return path

    def paint(self, painter, option, widget):
        # Body.
        painter.setBrush(self.color)
        painter.drawEllipse(-10, -20, 20, 40)

        # Eyes.
        painter.setBrush(Qt.white)
        painter.drawEllipse(-10, -17, 8, 8)
        painter.drawEllipse(2, -17, 8, 8)

        # Nose.
        painter.setBrush(Qt.black)
        painter.drawEllipse(QRectF(-2, -22, 4, 4))

        # Pupils.
        painter.drawEllipse(QRectF(-8.0 + self._mouse_eye_direction, -17, 4, 4))
        painter.drawEllipse(QRectF(4.0 + self._mouse_eye_direction, -17, 4, 4))

        # Ears.
        if self.scene().collidingItems(self):
            painter.setBrush(Qt.red)
        else:
            painter.setBrush(Qt.darkYellow)

        painter.drawEllipse(-17, -12, 16, 16)
        painter.drawEllipse(1, -12, 16, 16)

        # Tail.
        path = QPainterPath(QPointF(0, 20))
        path.cubicTo(-5, 22, -5, 22, 0, 25)
        path.cubicTo(5, 27, 5, 32, 0, 30)
        path.cubicTo(-5, 32, -5, 42, 0, 35)
        painter.setBrush(Qt.NoBrush)
        painter.drawPath(path)

    def advance(self, phase):
        if not phase:
            return
        # Don't move too far away.
        line_to_center = QLineF(QPointF(0, 0), self.mapFromScene(0, 0))
        if line_to_center.length() > 150:
            angle_to_center = math.acos(line_to_center.dx() / line_to_center.length())
            if line_to_center.dy() < 0:
                angle_to_center = Mouse.TWO_PI - angle_to_center
            angle_to_center = Mouse.normalize_angle((Mouse.PI - angle_to_center) + Mouse.PI / 2)

            if angle_to_center < Mouse.PI and angle_to_center > Mouse.PI / 4:
                # Rotate left.
                self.angle += [-0.25, 0.25][self.angle < -Mouse.PI / 2]
            elif angle_to_center >= Mouse.PI and angle_to_center < (Mouse.PI + Mouse.PI / 2 + Mouse.PI / 4):
                # Rotate right.
                self.angle += [-0.25, 0.25][self.angle < Mouse.PI / 2]
        elif math.sin(self.angle) < 0:
            self.angle += 0.25
        elif math.sin(self.angle) > 0:
            self.angle -= 0.25

        # Try not to crash with any other mice.
        danger_mice = self.scene().items(QPolygonF([self.mapToScene(0, 0),
                                                    self.mapToScene(-30, -50),
                                                    self.mapToScene(30, -50)]))

        for item in danger_mice:
            if item is self:
                continue

            line_to_mouse = QLineF(QPointF(0, 0), self.mapFromItem(item, 0, 0))
            angle_to_mouse = math.acos(line_to_mouse.dx() / line_to_mouse.length())
            if line_to_mouse.dy() < 0:
                angle_to_mouse = Mouse.TWO_PI - angle_to_mouse
            angle_to_mouse = Mouse.normalize_angle((Mouse.PI - angle_to_mouse) + Mouse.PI / 2)

            if angle_to_mouse >= 0 and angle_to_mouse < Mouse.PI / 2:
                # Rotate right.
                self.angle += 0.5
            elif angle_to_mouse <= Mouse.TWO_PI and angle_to_mouse > (Mouse.TWO_PI - Mouse.PI / 2):
                # Rotate left.
                self.angle -= 0.5

        # Add some random movement.
        if len(danger_mice) > 1 and random(10) == 0:
            if random(2) != 0:
                self.angle += random(100) / 500.0
            else:
                self.angle -= random(100) / 500.0

        self.speed += (-50 + random(100)) / 100.0

        dx = math.sin(self.angle) * 10

        self._mouse_eye_direction = [dx / 5, 0.0][abs(dx / 5) < 1]

        self.setRotation(self.rotation() + dx)
        self.setPos(self.mapToParent(0, -(3 + math.sin(self.speed) * 3)))


if __name__ == '__main__':
    MOUSE_COUNT = 7
    app = QApplication(sys.argv)

    scene = QGraphicsScene()
    scene.setSceneRect(-300, -300, 600, 600)
    scene.setItemIndexMethod(QGraphicsScene.NoIndex)

    for i in range(MOUSE_COUNT):
        mouse = Mouse()
        mouse.setPos(math.sin((i * 6.28) / MOUSE_COUNT) * 200,
                     math.cos((i * 6.28) / MOUSE_COUNT) * 200)
        scene.addItem(mouse)

    view = QGraphicsView(scene)
    view.setRenderHint(QPainter.Antialiasing)
    view.setBackgroundBrush(QBrush(QPixmap(':/images/cheese.jpg')))
    view.setCacheMode(QGraphicsView.CacheBackground)
    view.setViewportUpdateMode(QGraphicsView.BoundingRectViewportUpdate)
    view.setDragMode(QGraphicsView.ScrollHandDrag)
    view.setWindowTitle("Colliding Mice")
    view.resize(400, 300)
    view.show()

    timer = QTimer()
    timer.timeout.connect(scene.advance)
    timer.start(1000 / 33)
    sys.exit(app.exec())
