"""Regression tests for the Plotly canvas mouse-gesture layer.

plotly's built-in drag bindings (shift+left rotates, ctrl+left pans, middle
zooms, right pans) disagree with the PyVista backend's VTK trackball style, so
the Plotly canvas re-implements them in JS to match VTK: shift+left pan,
ctrl+left spin, middle pan, right zoom.

The page runs offscreen under QtWebEngine, where gl-plot3d's render loop is
throttled and camera animations do not advance, so these tests spy on the
gl-plot3d camera's ``view.pan`` / ``view.rotate`` calls and assert the mapping
(and that plotly's own handler is suppressed for the gesture) rather than the
resulting camera position. A full-camera smoke check is unnecessary here;
plotly owns the maths.
"""

from __future__ import annotations

import json
from pathlib import Path
from typing import Any

import pytest

pytest.importorskip("PySide6")
pytest.importorskip("plotly")

from otko.services import load_project

EXAMPLES = Path(__file__).resolve().parents[2] / "examples"

#: Install spies on the live camera, run one synthetic drag, report the calls.
#: ``keyBindingMode`` distinguishes our layer (false) from plotly's native
#: handler ('rotate'), which calls the same ``view`` methods.
_SPY_DRAG = """(function(){
  var gd = document.getElementById('plot');
  var s = gd._fullLayout.scene._scene;
  var cam = s.camera;
  var el = s.glplot.canvas;
  var r = el.getBoundingClientRect();
  var x0 = r.left + r.width/2, y0 = r.top + r.height/2;
  var calls = [];
  var origPan = cam.view.pan;
  var origRotate = cam.view.rotate;
  cam.view.pan = function (t, dx, dy, dz) {
    calls.push(['pan', cam.keyBindingMode, dx, dy, dz]);
  };
  cam.view.rotate = function (t, p, y, ro) {
    calls.push(['rotate', cam.keyBindingMode, p, y, ro]);
  };
  function ev(t, x, y, b) {
    el.dispatchEvent(new MouseEvent(t, {
      bubbles: true, cancelable: true, view: window,
      clientX: x, clientY: y, button: __BUTTON__, buttons: b,
      shiftKey: __SHIFT__, ctrlKey: __CTRL__, altKey: __ALT__
    }));
  }
  ev('mousedown', x0, y0, __BUTTONS__);
  ev('mousemove', x0 + 60, y0 + 40, __BUTTONS__);
  ev('mouseup', x0 + 60, y0 + 40, 0);
  cam.view.pan = origPan;
  cam.view.rotate = origRotate;
  return JSON.stringify({calls: calls, kbm: cam.keyBindingMode});
})()"""


def _js_bool(value: bool) -> str:
    return "true" if value else "false"


def _open_canvas(qtbot):  # type: ignore[no-untyped-def]
    from otko.views.canvas_plotly import PlotlyCanvas

    canvas = PlotlyCanvas()
    qtbot.addWidget(canvas)
    canvas.show_project(load_project(EXAMPLES / "basic_truss.osmodel"))
    qtbot.waitUntil(lambda: canvas._ready, timeout=30000)
    qtbot.wait(1500)  # let the first Plotly.react settle
    return canvas


def _run_js(canvas, qtbot, script: str, timeout: int = 15000):  # type: ignore[no-untyped-def]
    box: dict[str, object] = {}
    canvas._web.page().runJavaScript(script, lambda value: box.update(value=value))
    qtbot.waitUntil(lambda: "value" in box, timeout=timeout)
    return box["value"]


def _spy_drag(
    canvas,  # type: ignore[no-untyped-def]
    qtbot,
    *,
    button: int,
    buttons: int,
    shift: bool = False,
    ctrl: bool = False,
    alt: bool = False,
) -> dict[str, Any]:
    script = (
        _SPY_DRAG.replace("__BUTTON__", str(button))
        .replace("__BUTTONS__", str(buttons))
        .replace("__SHIFT__", _js_bool(shift))
        .replace("__CTRL__", _js_bool(ctrl))
        .replace("__ALT__", _js_bool(alt))
    )
    raw = _run_js(canvas, qtbot, script)
    assert isinstance(raw, str)
    return json.loads(raw)


def _ours(calls: list[list[Any]], kind: str) -> list[list[Any]]:
    return [c for c in calls if c[0] == kind and c[1] is False]


@pytest.mark.gui
def test_gesture_bindings_match_vtk(qtbot) -> None:  # type: ignore[no-untyped-def]
    """One page for all gestures: each QWebEngineView costs a WebGL context."""
    canvas = _open_canvas(qtbot)

    # Shift+left pans (not plotly's rotate).
    result = _spy_drag(canvas, qtbot, button=0, buttons=1, shift=True)
    pans = _ours(result["calls"], "pan")
    assert pans and pans[0][3] != 0, result
    assert not _ours(result["calls"], "rotate"), result
    assert result["kbm"] == "rotate", "binding must be restored after the drag"

    # Middle drag pans, not zooms.
    result = _spy_drag(canvas, qtbot, button=1, buttons=4)
    pans = _ours(result["calls"], "pan")
    assert pans and pans[0][3] != 0 and pans[0][4] == 0, result
    assert result["kbm"] == "rotate", result

    # Right drag dollies (z pan), not plotly's pan.
    result = _spy_drag(canvas, qtbot, button=2, buttons=2)
    zooms = [c for c in _ours(result["calls"], "pan") if c[2] == 0 and c[3] == 0]
    assert zooms and zooms[0][4] != 0, result
    assert result["kbm"] == "rotate", result

    # Ctrl+left spins (pure roll).
    result = _spy_drag(canvas, qtbot, button=0, buttons=1, ctrl=True)
    rolls = [c for c in _ours(result["calls"], "rotate") if c[2] == 0 and c[3] == 0]
    assert rolls and rolls[0][4] != 0, result
    assert result["kbm"] == "rotate", result

    # Alt is not a VTK modifier: it falls back to a plain rotate.
    result = _spy_drag(canvas, qtbot, button=0, buttons=1, alt=True)
    rots = [c for c in _ours(result["calls"], "rotate") if c[4] == 0]
    assert rots and (rots[0][2] != 0 or rots[0][3] != 0), result
    assert result["kbm"] == "rotate", result

    # Plain left drag stays on plotly's native path (keyBindingMode 'rotate').
    result = _spy_drag(canvas, qtbot, button=0, buttons=1)
    assert not _ours(result["calls"], "pan"), result
    assert not _ours(result["calls"], "rotate"), result
    assert any(c[1] == "rotate" for c in result["calls"]), result
    assert result["kbm"] == "rotate", result

    # In-page animation entry points are exposed to Python.
    assert (
        _run_js(
            canvas,
            qtbot,
            "typeof window.otkoAnimate === 'function' && "
            "typeof window.otkoStopAnimation === 'function'",
        )
        is True
    )