"""Replay of a recording: the reader, and the depth replay policy.

Depth is not stored with a recording (team decision): replay recomputes it from
``raw_*.mp4`` and the recorded config. These tests cover the reader contract and
that the policy's risks are reported instead of discovered later.
"""

from __future__ import annotations

import csv
import json
import shutil
import sys
import types
from pathlib import Path

import numpy as np
import pytest

from orisys_app_shared.acquisition.sdk_worker import SdkPacket
from orisys_app_shared.record import (
    ExperimentRecorder,
    RecordConfig,
    RecordingReader,
    list_recordings,
)
from orisys_app_shared.record.depth import DepthRecomputer

SCRATCH = Path(__file__).resolve().parent / "_scratch_playback"


def _packet(index: int, *, valid: bool = True) -> SdkPacket:
    nan = float("nan")
    frame = np.full((24, 32, 3), (index * 5) % 255, np.uint8)
    return SdkPacket(
        raw_frame=frame,
        processed_frame=frame,
        timestamp=1000.0 + index / 30.0,
        fps=30.0,
        process_ms=1.0,
        normal_force=2.0 if valid else nan,
        shear_x=0.5 if valid else nan,
        shear_y=-0.5 if valid else nan,
        normal_force_raw=(9.0 + index * 0.1) if valid else nan,
        shear_x_raw=0.4 if valid else nan,
        shear_y_raw=-0.4 if valid else nan,
        force_unit="N",
        force_calibrated=True,
        session_id=1,
        frame_id=index,
        valid=valid,
        invalid_reason="" if valid else "read failed",
        raw_available=True,
    )


@pytest.fixture
def recording():
    shutil.rmtree(SCRATCH, ignore_errors=True)
    SCRATCH.mkdir(parents=True, exist_ok=True)
    recorder = ExperimentRecorder(RecordConfig(video=True, fps=30.0, segment_seconds=0.4))
    directory = recorder.start(
        root=SCRATCH,
        session_id=3,
        calibration_id="/cfg/sensor.json",
        metadata={
            "device": {
                "sensor_type": "box",
                "config_ref": str(SCRATCH / "sensor.json"),
                "config_sha256": "recorded-hash",
            },
            "versions": {"sdk": "0.5.1"},
            "depth": {"stored": False, "replay": "recompute"},
        },
    )
    (SCRATCH / "sensor.json").write_text('{"camera": {}}\n', encoding="utf-8")
    for index in range(60):
        recorder.on_packet(_packet(index))
    recorder.on_packet(_packet(90, valid=False))
    recorder.stop()
    yield directory
    shutil.rmtree(SCRATCH, ignore_errors=True)


def test_reader_reports_the_recording_shape(recording):
    reader = RecordingReader(recording)
    info = reader.info()

    assert len(info.frames) == 61
    assert info.times.size == 61
    assert info.duration_s == pytest.approx(3.0, abs=0.05)
    assert int(info.valid.sum()) == 60, "the failed readout should be marked invalid"


def test_reader_keeps_unavailable_values_empty(recording):
    reader = RecordingReader(recording)
    info = reader.info()
    assert np.isnan(info.raw[-1]).all(), "an empty CSV cell must not read back as 0"
    assert np.isfinite(info.raw[0]).all()


def test_reader_maps_time_to_the_video_segment(recording):
    reader = RecordingReader(recording)
    frame = reader.frame_at(1.0)

    assert frame is not None
    assert frame.frame_id == 30
    assert frame.t_rel_s == pytest.approx(1.0, abs=0.02)
    assert frame.in_video
    assert frame.segment >= 1
    assert reader.segment_path(frame.segment) is not None
    # Before the start and past the end clamp instead of raising.
    assert reader.frame_at(-5.0).frame_id == 0
    assert reader.frame_at(500.0).frame_id == 90


def test_reader_decodes_the_video_frame(recording):
    import cv2

    if not hasattr(cv2, "VideoCapture"):  # pragma: no cover
        pytest.skip("no video backend")
    reader = RecordingReader(recording)
    image, frame = reader.video_frame_at(1.0)

    assert frame is not None and frame.in_video
    assert image is not None, "the frame index and the video disagreed"
    assert image.shape[:2] == (24, 32)


def test_reader_window_and_streaming_agree(recording):
    reader = RecordingReader(recording)
    times, values = reader.forces_window(0.5, 1.0)
    assert len(times) == 16
    assert values.shape == (16, 3)

    streamed = sum(len(batch_times) for batch_times, _ in reader.iter_forces(batch=25))
    assert streamed == 61, "streaming must see every row"


def test_an_empty_recording_directory_is_readable():
    """A folder with no CSVs must open (empty), not raise an unpack error."""
    shutil.rmtree(SCRATCH, ignore_errors=True)
    SCRATCH.mkdir(parents=True, exist_ok=True)
    try:
        reader = RecordingReader(SCRATCH)
        info = reader.info()
        assert info.frames == []
        assert info.times.size == 0
        assert info.duration_s == 0.0
        assert reader.frame_at(1.0) is None
        assert reader.replay_warnings(sdk_version="0.5.1")
    finally:
        shutil.rmtree(SCRATCH, ignore_errors=True)


def test_a_new_recording_is_reported_as_time_ordered(recording):
    info = RecordingReader(recording).info()
    assert info.frames_out_of_order, "the writer no longer produces ordered rows"
    assert info.forces_out_of_order
    codes = RecordingReader(recording).replay_warnings(sdk_version="0.5.1")
    assert "out_of_order" not in codes


def test_an_old_out_of_order_recording_is_re_sorted_and_reported():
    """Rows written by the pre-fix writer are not in time order.

    ``frame_at`` binary-searches these times, so an unsorted file would answer
    with the wrong frame; the reader sorts and says so instead.
    """
    shutil.rmtree(SCRATCH, ignore_errors=True)
    SCRATCH.mkdir(parents=True, exist_ok=True)
    (SCRATCH / "forces.csv").write_text(
        "session_id,frame_id,t_rel_s,FN_raw,FX_raw,FY_raw,FN_N,FX_N,FY_N,valid,calibration_id\n"
        "1,0,0.0,1.0,0.1,0.1,2.0,0.1,0.1,1,h\n"
        "1,2,0.066,3.0,0.1,0.1,6.0,0.1,0.1,1,h\n"  # written before frame 1
        "1,1,0.033,2.0,0.1,0.1,4.0,0.1,0.1,1,h\n",
        encoding="utf-8",
    )
    (SCRATCH / "frames.csv").write_text(
        "frame_id,t_rel_s,acquired_at,segment,segment_frame,in_video,dropped\n"
        "0,0.0,2026-01-01T00:00:00.000Z,1,1,1,0\n"
        "2,0.066,2026-01-01T00:00:00.066Z,1,3,1,0\n"
        "1,0.033,2026-01-01T00:00:00.033Z,1,2,1,0\n",
        encoding="utf-8",
    )
    (SCRATCH / "session.json").write_text(
        json.dumps(
            {
                "format_version": "1.1",
                "device": {"sensor_type": "box", "config_ref": "/cfg/sensor.json"},
                "versions": {"sdk": "0.5.1"},
                "depth": {"stored": False},
            }
        ),
        encoding="utf-8",
    )
    try:
        reader = RecordingReader(SCRATCH)
        info = reader.info()
        assert not info.frames_out_of_order
        assert not info.forces_out_of_order
        assert [frame.frame_id for frame in info.frames] == [0, 1, 2]
        assert info.times.tolist() == pytest.approx([0.0, 0.033, 0.066])
        # The binary search is only valid because the rows were sorted.
        assert reader.frame_at(0.05).frame_id == 1
        assert reader.frame_at(0.07).frame_id == 2
        assert "out_of_order" in reader.replay_warnings(sdk_version="0.5.1")
    finally:
        shutil.rmtree(SCRATCH, ignore_errors=True)


def test_depth_policy_says_recompute_and_warns_about_drift(recording):
    reader = RecordingReader(recording)

    assert reader.depth_is_stored() is False
    assert reader.depth_policy().get("replay") == "recompute"
    assert reader.recorded_config_ref() == str(SCRATCH / "sensor.json")

    # The config file on disk no longer matches what was recorded.
    codes = reader.replay_warnings(sdk_version="0.5.1")
    assert "config_changed" in codes
    assert "depth_recomputed" in codes

    # Same SDK: no version warning.
    assert "sdk_changed" not in codes
    assert "sdk_changed" in reader.replay_warnings(sdk_version="9.9.9")


def test_depth_recompute_preflight_states_why_it_cannot_run(recording):
    reader = RecordingReader(recording)
    recomputer = DepthRecomputer(reader)
    try:
        problem = recomputer.preflight()
        assert problem in ("", "sdk_unavailable"), problem

        # A recording with no config reference is refused, not guessed at.
        missing = RecordingReader(recording)
        missing._info = None  # noqa: SLF001 - force a re-read below
        empty = SCRATCH / "empty"
        empty.mkdir(exist_ok=True)
        (empty / "forces.csv").write_text(
            ",".join(("session_id", "frame_id", "t_rel_s", "FN_raw", "FX_raw", "FY_raw",
                      "FN_N", "FX_N", "FY_N", "valid", "calibration_id")) + "\n",
            encoding="utf-8",
        )
        (empty / "session.json").write_text(json.dumps({"depth": {"stored": False}}), encoding="utf-8")
        bare = DepthRecomputer(RecordingReader(empty))
        assert bare.preflight() in ("config_missing", "no_video", "sdk_unavailable")
    finally:
        recomputer.close()


def test_depth_result_is_failed_not_blank_when_sdk_is_missing(recording):
    """A missing SDK must produce an explicit error, never a stand-in image."""
    saved = sys.modules.get("orisys")
    blocker = types.ModuleType("orisys")
    try:
        # A module object with no Sensor/DEPTH surface: importing succeeds but
        # nothing can be recomputed with it.
        sys.modules["orisys"] = blocker
        reader = RecordingReader(recording)
        recomputer = DepthRecomputer(reader)
        problem = recomputer.preflight()
        assert problem in ("sdk_unavailable", ""), problem
        if problem:
            result = recomputer.depth_at(1.0)
            assert not result.ok
            assert result.depth is None
            assert result.error
    finally:
        if saved is None:
            sys.modules.pop("orisys", None)
        else:
            sys.modules["orisys"] = saved


def test_list_recordings_finds_directories_newest_first(recording):
    second = SCRATCH / "zzz_later"
    second.mkdir()
    (second / "forces.csv").write_text("", encoding="utf-8")

    found = list_recordings(SCRATCH)
    assert found[0].name == "zzz_later", "recordings should be newest first"
    assert recording in found


if __name__ == "__main__":  # pragma: no cover - manual runner
    import shutil as _shutil

    failures = 0
    for name, function in sorted(globals().items()):
        if not name.startswith("test_") or not callable(function):
            continue
        try:
            if name == "test_list_recordings_finds_directories_newest_first":
                _shutil.rmtree(SCRATCH, ignore_errors=True)
                SCRATCH.mkdir(parents=True, exist_ok=True)
                recorder = ExperimentRecorder(RecordConfig(video=False))
                directory = recorder.start(
                    root=SCRATCH, session_id=1, metadata={"depth": {"stored": False}}
                )
                recorder.on_packet(_packet(0))
                recorder.stop()
                try:
                    function(directory)
                finally:
                    _shutil.rmtree(SCRATCH, ignore_errors=True)
                print(f"  ok   {name}")
                continue
            _shutil.rmtree(SCRATCH, ignore_errors=True)
            SCRATCH.mkdir(parents=True, exist_ok=True)
            recorder = ExperimentRecorder(RecordConfig(video=True, fps=30.0, segment_seconds=0.4))
            directory = recorder.start(
                root=SCRATCH,
                session_id=3,
                calibration_id="/cfg/sensor.json",
                metadata={
                    "device": {
                        "sensor_type": "box",
                        "config_ref": str(SCRATCH / "sensor.json"),
                        "config_sha256": "recorded-hash",
                    },
                    "versions": {"sdk": "0.5.1"},
                    "depth": {"stored": False, "replay": "recompute"},
                },
            )
            (SCRATCH / "sensor.json").write_text('{"camera": {}}\n', encoding="utf-8")
            for index in range(60):
                recorder.on_packet(_packet(index))
            recorder.on_packet(_packet(90, valid=False))
            recorder.stop()
            try:
                function(directory)
            finally:
                _shutil.rmtree(SCRATCH, ignore_errors=True)
            print(f"  ok   {name}")
        except Exception as exc:  # noqa: BLE001
            failures += 1
            print(f"  FAIL {name}: {type(exc).__name__}: {exc}")
    print(f"failures: {failures}")
    raise SystemExit(1 if failures else 0)