"""Shared drag gestures, with real Qt events and C math, without SETGUI imports."""
import ctypes
import os
import unittest
from dataclasses import replace

os.environ.setdefault('QT_QPA_PLATFORM', 'offscreen')
try:
    from PySide6.QtCore import QEvent, QPoint, QPointF, QRectF, Qt, Signal
    from PySide6.QtGui import QMouseEvent
    from PySide6.QtTest import QTest
    from PySide6.QtWidgets import QApplication, QCheckBox, QWidget
except ImportError:
    from PySide2.QtCore import QEvent, QPoint, QPointF, QRectF, Qt, Signal
    from PySide2.QtGui import QMouseEvent
    from PySide2.QtTest import QTest
    from PySide2.QtWidgets import QApplication, QCheckBox, QWidget

from protocan.plot import Bounds, Marker, Markers, PlotMath, Viewport
from set_devices.qt_ports.plot_drag import PlotDragInteraction


class Canvas(PlotDragInteraction, QWidget):
    view_changed = Signal()

    def __init__(self, core):
        super().__init__()
        self.core = core
        self.viewport = Viewport(.25, .25, .5, .5)
        self.markers = replace(Markers(a=40, b=60, e=50, f=65), y_enabled=True)
        self.marker_mode = QCheckBox(self)
        self.marker_mode.setChecked(True)
        self.marker_mode.hide()
        self.has_plot_data = True
        self.lock_x = self.lock_y = False
        self._press = self._dragged = None
        self.single_clicks = []
        self.resize(440, 340)

    @property
    def visible_bounds(self):
        return Bounds(0, 100, 0, 100).visible(self.core, self.viewport)

    def plot_rect(self):
        return QRectF(20, 20, 400, 300)

    def value_rect(self):
        return QRectF(20, 20, 400, 200)

    def _refresh_controls(self):
        pass

    def _single_cursor_click(self, pos):
        self.single_clicks.append(pos)


@unittest.skipUnless(os.environ.get('SETPROTOCOL_LIBRARY'), 'Set SETPROTOCOL_LIBRARY')
class PlotDragTests(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        cls.app = QApplication.instance() or QApplication([])
        cls.core = PlotMath(ctypes.CDLL(os.environ['SETPROTOCOL_LIBRARY']))

    def setUp(self):
        self.plot = Canvas(self.core)
        self.plot.show()
        self.app.processEvents()

    def tearDown(self):
        self.plot.close()

    def drag(self, start, end, modifiers=Qt.NoModifier):
        QTest.mousePress(self.plot, Qt.LeftButton, modifiers, start)
        QTest.mouseRelease(self.plot, Qt.LeftButton, modifiers, end)

    def test_empty_space_pans_x_and_preserves_markers(self):
        before, markers = self.plot.viewport, self.plot.markers
        self.drag(QPoint(220, 180), QPoint(260, 210))
        self.assertEqual(before.transform(self.core, pan_x=.1), self.plot.viewport)
        self.assertEqual(markers, self.plot.markers)

    def test_shift_over_marker_pans_only_y_and_respects_lock(self):
        before, markers = self.plot.viewport, self.plot.markers
        self.drag(QPoint(140, 180), QPoint(180, 200), Qt.ShiftModifier)
        self.assertEqual(before.transform(self.core, pan_y=.1), self.plot.viewport)
        self.assertEqual(markers, self.plot.markers)
        self.plot.lock_y = True
        before = self.plot.viewport
        self.drag(QPoint(140, 180), QPoint(180, 200), Qt.ShiftModifier)
        self.assertEqual(before, self.plot.viewport)

    def test_marker_capture_in_analog_and_digital_panes(self):
        before = self.plot.viewport
        # X marker A at x=140 remains draggable in a digital lane.
        self.drag(QPoint(145, 270), QPoint(185, 290))
        self.assertAlmostEqual(45, self.plot.markers.a)
        self.assertEqual(before, self.plot.viewport)
        # Y marker E at y=120 uses the analog pane's height.
        self.drag(QPoint(220, 125), QPoint(240, 145))
        self.assertAlmostEqual(45, self.plot.markers.e)
        self.assertEqual(before, self.plot.viewport)

    def test_click_miss_and_locked_x_do_not_move_markers(self):
        before, markers = self.plot.viewport, self.plot.markers
        self.drag(QPoint(220, 180), QPoint(220, 180))
        self.assertEqual(before, self.plot.viewport)
        self.assertEqual(markers, self.plot.markers)
        self.assertEqual(1, len(self.plot.single_clicks))
        self.plot.lock_x = True
        self.drag(QPoint(220, 180), QPoint(260, 210))
        self.assertEqual(before, self.plot.viewport)
        self.assertEqual(markers, self.plot.markers)
        self.assertEqual(1, len(self.plot.single_clicks))

    def test_marker_click_and_drag_returning_to_start_are_not_single_clicks(self):
        point = QPoint(220, 180)
        self.drag(QPoint(140, 180), QPoint(140, 180))
        QTest.mousePress(self.plot, Qt.LeftButton, pos=point)
        moved = point + QPoint(40, 0)
        event = QMouseEvent(QEvent.MouseMove, QPointF(moved),
                           QPointF(self.plot.mapToGlobal(moved)),
                           Qt.NoButton, Qt.LeftButton, Qt.NoModifier)
        self.app.sendEvent(self.plot, event)
        QTest.mouseRelease(self.plot, Qt.LeftButton, pos=point)
        self.assertEqual([], self.plot.single_clicks)


if __name__ == '__main__':
    unittest.main()