"""The wheel guard is motor protection: a bare wheel over a value widget must
never change the value (it scrolls the page instead); adjusting requires the
deliberate right-button + wheel gesture."""

import pytest
from PySide6.QtCore import QPoint, QPointF, Qt
from PySide6.QtGui import QWheelEvent
from PySide6.QtWidgets import (
    QApplication,
    QScrollArea,
    QSlider,
    QSpinBox,
    QVBoxLayout,
    QWidget,
    QWidgetItem,
)

from aare.gui.widgets.wheel_value_guard import WheelValueGuard


@pytest.fixture
def guard(qapp):
    guard = WheelValueGuard()
    qapp.installEventFilter(guard)
    yield guard
    qapp.removeEventFilter(guard)


def _wheel(buttons):
    return QWheelEvent(
        QPointF(5, 5),
        QPointF(5, 5),
        QPoint(0, 0),
        QPoint(0, 120),
        buttons,
        Qt.KeyboardModifier.NoModifier,
        Qt.ScrollPhase.NoScrollPhase,
        False,
    )


def test_bare_wheel_does_not_adjust(guard, qtbot):
    slider = QSlider(Qt.Orientation.Horizontal)
    qtbot.addWidget(slider)
    slider.setRange(0, 100)
    slider.setValue(50)
    QApplication.sendEvent(slider, _wheel(Qt.MouseButton.NoButton))
    assert slider.value() == 50


def test_right_button_wheel_adjusts(guard, qtbot):
    slider = QSlider(Qt.Orientation.Horizontal)
    qtbot.addWidget(slider)
    slider.setRange(0, 100)
    slider.setValue(50)
    QApplication.sendEvent(slider, _wheel(Qt.MouseButton.RightButton))
    assert slider.value() != 50


def test_bare_wheel_scrolls_the_enclosing_area(guard, qtbot):
    area = QScrollArea()
    qtbot.addWidget(area)
    content = QWidget()
    layout = QVBoxLayout(content)
    spin = QSpinBox()
    spin.setRange(0, 100)
    spin.setValue(50)
    layout.addWidget(spin)
    # Tall filler so the area has something to scroll.
    filler = QWidget()
    filler.setFixedHeight(2000)
    layout.addWidget(filler)
    area.setWidget(content)
    area.resize(200, 200)
    area.show()
    bar = area.verticalScrollBar()
    bar.setValue(bar.maximum() // 2)
    before = bar.value()

    QApplication.sendEvent(spin, _wheel(Qt.MouseButton.NoButton))
    assert spin.value() == 50
    assert bar.value() != before


def test_a_non_event_argument_is_ignored(guard, qtbot):
    # PySide 6.9 can hand an app-level filter a QWidgetItem instead of a
    # QEvent during layout teardown; raising there fails a random test.
    widget = QWidget()
    qtbot.addWidget(widget)
    assert guard.eventFilter(widget, QWidgetItem(widget)) is False