# SPDX-License-Identifier: MIT
#
# Tests for XFree86-VidModeExtension.

import struct

import pytest

from proto import vidmode
from xclient import Extension, X11Error, X11Reply


class TestVidModeSwitchToMode:
    @pytest.mark.swapped_client
    @pytest.mark.xorg_only
    def test_switch_to_mode_fields_swapped(self, xserver, xclient_swapped):
        """
        SProcVidModeSwitchToMode previously only swapped stuff->screen.
        All mode-line fields (dotclock, hdisplay, …) were left in
        wire byte order, so ProcVidModeSwitchToMode could never match
        them against any existing mode → BadValue.

        Strategy: query the current mode with GetModeLine, then send
        the same timings back via SwitchToMode.  With the fix the
        values match → success.  Without the fix the garbled timings
        don't match anything → BadValue error.

        Fixed in commit 751e631e1c99 ("Xext/vidmode: fix
        SProcVidModeSwitchToMode swapping only screen field").
        """
        conn = xclient_swapped

        ext = conn.query_extension(Extension.XF86VIDMODE)
        if not ext:
            pytest.skip("XF86-VidModeExtension not available")

        req = vidmode.QueryVersionRequest(opcode=ext.opcode)
        conn.send_request(req.to_bytes(">"))
        resp = conn.recv_response(timeout=5.0)
        if not isinstance(resp, X11Reply):
            pytest.skip("VidMode QueryVersion failed")

        # Get the current mode line so we can echo it back.
        # xXF86VidModeGetModeLineReply (v2, 52 bytes):
        #   [8]  dotclock(4)
        #   [12] hdisplay(2)  hsyncstart(2)
        #   [16] hsyncend(2)  htotal(2)
        #   [20] hskew(4)
        #   [24] vdisplay(2)  vsyncstart(2)
        #   [28] vsyncend(2)  vtotal(2)
        #   [32] flags(4)
        #   [36] privsize(4)
        req = vidmode.GetModeLineRequest(
            opcode=ext.opcode,
            screen=0,
        )
        conn.send_request(req.to_bytes(">"))
        resp = conn.recv_response(timeout=5.0)

        if isinstance(resp, X11Error):
            pytest.skip("GetModeLine not supported (VidMode not initialised?)")
        assert isinstance(resp, X11Reply), f"Expected reply, got {resp}"
        assert len(resp.data) >= 40, f"Reply too short: {len(resp.data)}"

        dotclock = struct.unpack_from(">I", resp.data, 8)[0]
        hdisplay = struct.unpack_from(">H", resp.data, 12)[0]
        hsyncstart = struct.unpack_from(">H", resp.data, 14)[0]
        hsyncend = struct.unpack_from(">H", resp.data, 16)[0]
        htotal = struct.unpack_from(">H", resp.data, 18)[0]
        hskew = struct.unpack_from(">I", resp.data, 20)[0]
        vdisplay = struct.unpack_from(">H", resp.data, 24)[0]
        vsyncstart = struct.unpack_from(">H", resp.data, 26)[0]
        vsyncend = struct.unpack_from(">H", resp.data, 28)[0]
        vtotal = struct.unpack_from(">H", resp.data, 30)[0]
        flags = struct.unpack_from(">I", resp.data, 32)[0]

        # Switch to the same mode — should succeed.
        req = vidmode.SwitchToModeRequest(
            opcode=ext.opcode,
            screen=0,
            dotclock=dotclock,
            hdisplay=hdisplay,
            hsyncstart=hsyncstart,
            hsyncend=hsyncend,
            htotal=htotal,
            hskew=hskew,
            vdisplay=vdisplay,
            vsyncstart=vsyncstart,
            vsyncend=vsyncend,
            vtotal=vtotal,
            flags=flags,
            privsize=0,
        )
        conn.send_request(req.to_bytes(">"))
        resp = conn.recv_response(timeout=2.0)

        assert xserver.is_alive, "Server crashed"
        # With the fix: no response (void request, success).
        # Without the fix: BadValue error because the garbled
        # timing fields don't match any mode.
        if resp is not None:
            assert not isinstance(resp, X11Error), (
                f"SwitchToMode returned error {resp} - "
                f"mode-line fields not byte-swapped in "
                f"SProcVidModeSwitchToMode"
            )