"""Review of the rail's unified play control: play/pause, stop, reset — and nothing else.

Written against the requirement rather than the implementation:

* the play-control group is exactly **play/pause**, **stop**, **reset** (no extra pause
  button, no role switch that turns the third button into a stop);
* the primary button is a play/pause toggle in **both** views, and pressing it while a
  session runs pauses without stopping — the device stays connected;
* stop ends the session (live) or leaves the replay (playback);
* reset is disabled in the replay view, where there is no tracker to zero.
"""

from __future__ import annotations

import ui_check

from tests.conftest import finish_run, running_window, show_window


def test_the_group_is_exactly_play_pause_stop_reset(make_window):
    window = show_window(make_window(sensor_type="box", source_mode="camera"), (1440, 880))
    toolbar = window.toolbar
    assert not hasattr(toolbar, "btn_pause"), "an extra pause button is still in the rail"
    assert hasattr(toolbar, "btn_stop"), "there is no dedicated stop button"
    assert not hasattr(toolbar, "set_reset_role"), (
        "the reset button still switches role to stop; one control cannot be two"
    )
    assert toolbar.btn_run.isCheckable(), "the play/pause control must be a toggle"
    window.close()


def test_the_primary_button_pauses_and_does_not_stop(make_window):
    """The heart of the unification: one toggle, three states, and stop is not the toggle."""
    window, stuck = running_window(make_window)
    try:
        assert window._session_active, "the fixture did not start a session"
        assert window.toolbar.btn_run.isChecked(), (
            "a running session must show the transport as engaged (pause available)"
        )
        assert "暂停" in window.toolbar.btn_run.text() or "Paus" in window.toolbar.btn_run.text(), (
            f"a running session reads {window.toolbar.btn_run.text()!r}, not pause"
        )

        # Press it: pause, not stop.
        window.toolbar.btn_run.setChecked(False)
        assert window._session_active, "pressing the transport ended the session"
        assert window._display_paused is True, "the window did not record the pause"
        assert stuck.is_paused is True, "the worker was not paused"
        assert "继续" in window.toolbar.btn_run.text() or "Resume" in window.toolbar.btn_run.text(), (
            f"a paused session reads {window.toolbar.btn_run.text()!r}, not resume"
        )

        # Press it again: resume.
        window.toolbar.btn_run.setChecked(True)
        assert window._display_paused is False
        assert stuck.is_paused is False, "the worker was not resumed"
        assert window._session_active, "resuming ended the session"
    finally:
        finish_run(window, stuck)


def test_stop_ends_the_session(make_window):
    window, stuck = running_window(make_window)
    try:
        # A first frame is what makes the session a *running* one (the rail's reset and
        # the phase both key off it), so drive one before pressing stop.
        stuck.emit(ui_check._fake_packet(1))
        window._on_run_tick()
        assert window.toolbar.btn_stop.isEnabled(), "stop is not reachable while running"

        window.toolbar.btn_stop.click()
        assert window._session_phase != "running", (
            f"the stop button left the session in {window._session_phase!r}"
        )
        assert not window.toolbar.btn_run.isChecked(), "the transport stayed engaged after stop"
        assert window._display_paused is False, "the pause flag survived the stop"
    finally:
        stuck.release()


def test_reset_is_for_the_device_and_is_disabled_in_the_replay_view(make_window):
    """Reset stays a *device* control, and it is the thing the replay view cannot offer.

    The enabled state of reset once frames are flowing is covered by
    ``test_ui_smoke.py::test_a_reset_reaches_the_device_and_is_recorded`` (which drives
    ``_on_reset``); this test pins what the unification is about: reset and stop are two
    different controls, and the replay view disables the one that needs a device.
    """
    window, stuck = running_window(make_window)
    try:
        assert window.toolbar.btn_reset.text() != window.toolbar.btn_stop.text(), (
            "reset and stop must be distinguishable controls"
        )
        assert window.toolbar.btn_stop.isEnabled(), "stop is not reachable during a session"
    finally:
        finish_run(window, stuck)

    replay = show_window(make_window(sensor_type="box", source_mode="camera"), (1440, 880))
    replay.brand_bar.btn_playback.click()
    assert not replay.toolbar.btn_reset.isEnabled(), (
        "reset is offered in the replay view, where there is no tracker to zero"
    )
    assert hasattr(replay.toolbar, "btn_stop"), "the replay view has no stop control"
    assert replay.toolbar.btn_run.text().startswith("▶"), (
        f"the replay transport idle reads {replay.toolbar.btn_run.text()!r}, not play"
    )
    replay.close()