"""Pytest fixtures for the AZ-404 E2E replay tests.

The fixtures are import-clean on dev macOS — the heavy work
(synthesizing the tlog, invoking the airborne CLI in a subprocess)
runs only when ``RUN_REPLAY_E2E=1`` is set in the environment.
Without the env var, the test module's collection-time skip marker
prevents the fixtures from being requested.
"""

from __future__ import annotations

import json
import os
import shutil
import subprocess
import sys
from collections.abc import Iterator
from dataclasses import dataclass
from pathlib import Path
from typing import Any

import pytest

from gps_denied_onboard.replay_input import load_tlog_ground_truth
from tests.e2e.replay._helpers import GroundTruthRow, load_ground_truth_csv
from tests.e2e.replay._tlog_synth import synthesize_tlog


# Duration cap used exclusively for the realtime-pacing test.  The full
# Derkachi flight is ~490 s; running it at realtime pace in CI would take
# ~8 minutes. The realtime test passes --max-duration-s to the CLI so
# only this short clip is paced at wall-clock speed.
_REALTIME_TEST_CLIP_S: float = 60.0


# ----------------------------------------------------------------------
# Path helpers


def _repo_root() -> Path:
    return Path(__file__).resolve().parents[3]


def _derkachi_dir() -> Path:
    return _repo_root() / "_docs" / "00_problem" / "input_data" / "flight_derkachi"


def _calibration_path() -> Path:
    # AZ-702 ships a factory-sheet approximation for the Topotek
    # KHP20S30 nadir camera at
    # `_docs/00_problem/input_data/flight_derkachi/khp20s30_factory.json`.
    # When present we use it; otherwise we fall back to the
    # `adti26.json` placeholder so the AC-1/2/5/6 path stays
    # exercisable on dev macOS without the AZ-702 deliverable.
    factory_path = _derkachi_dir() / "khp20s30_factory.json"
    if factory_path.is_file():
        return factory_path
    return _repo_root() / "tests" / "fixtures" / "calibration" / "adti26.json"


# ----------------------------------------------------------------------
# Fixtures


@dataclass(frozen=True)
class DerkachiReplayInputs:
    """Bundle of paths the AZ-402 CLI consumes for a Derkachi replay run."""

    video_path: Path
    tlog_path: Path
    calibration_path: Path
    config_path: Path
    signing_key_path: Path
    output_path: Path
    ground_truth: list[GroundTruthRow]


@pytest.fixture(scope="session")
def derkachi_replay_inputs(tmp_path_factory: pytest.TempPathFactory) -> DerkachiReplayInputs:
    """Materialise Derkachi inputs + a synthesized tlog for the e2e run.

    Session-scoped so the tlog synthesizer runs once across the whole
    e2e collection. The tlog is cached at
    ``tmp_path_factory.mktemp("derkachi") / "synth.tlog"`` so each
    pytest invocation gets a fresh copy; the synthesizer is fast
    enough (~1 s for 60 s of data) that disk caching across invocations
    is unnecessary.
    """
    derkachi = _derkachi_dir()
    csv_path = derkachi / "data_imu.csv"
    video_path = derkachi / "flight_derkachi.mp4"
    real_tlog_path = derkachi / "derkachi.tlog"
    if not video_path.is_file():
        pytest.fail(f"Derkachi fixture missing: {video_path}")

    work_dir = tmp_path_factory.mktemp("derkachi")
    # AZ-697: prefer the real binary tlog when present; fall back to
    # synthesizing one from the CSV so dev environments without the
    # 5.8 MB binary blob still exercise the e2e path.
    if real_tlog_path.is_file():
        tlog_path = real_tlog_path
        gt_series = load_tlog_ground_truth(real_tlog_path).records
        ground_truth_full = [
            GroundTruthRow(
                t_s=fix.ts_ns / 1e9,
                lat_deg=fix.lat_deg,
                lon_deg=fix.lon_deg,
                alt_m=fix.alt_m,
            )
            for fix in gt_series
        ]
    else:
        if not csv_path.is_file():
            pytest.fail(
                f"Derkachi fixture missing: {csv_path} — see "
                "_docs/00_problem/input_data/flight_derkachi/README.md"
            )
        tlog_path = work_dir / "synth.tlog"
        synthesize_tlog(csv_path, tlog_path)
        ground_truth_full = load_ground_truth_csv(csv_path)

    # Empty signing key — the airborne replay path runs the signing
    # handshake against `NoopMavlinkTransport`, so the key contents do
    # not affect any wire output. We still need a real file because
    # the CLI's path-validation gate requires it.
    signing_key_path = work_dir / "signing_key.bin"
    signing_key_path.write_bytes(b"\x00" * 32)

    config_path = work_dir / "config.yaml"
    config_path.write_text(
        # Replay-specific overrides; the rest comes from the env vars
        # the airborne binary's `load_config` honours by default.
        #
        # Per-component blocks at the TOP LEVEL — the YAML loader
        # in `gps_denied_onboard.config.loader._load_yaml_files`
        # treats each top-level mapping as a block whose key is a
        # registry slug; nesting the slugs under a `components:`
        # wrapper makes the loader silently drop them (the wrapper
        # is not a registered slug).
        #
        # Open-loop ESKF composition profile (AZ-776 / ADR-012):
        # `c4_pose.enabled = false` strips C4 from the composition
        # graph so the airborne binary can run the mandatory simple
        # baseline (KLT/RANSAC VIO + ESKF state estimator) end-to-end
        # without a C4 anchor. ESKF has no iSAM2 graph for C4 to
        # anchor against; the `compose_root` validation gate rejects
        # the off-diagonal pairings (`enabled=False` + `gtsam_isam2`
        # or `enabled=True` + `eskf`) with a `CompositionError`.
        # Position drifts open-loop without C2/C3/C4 satellite
        # re-anchoring — AZ-777 (Derkachi C6 reference tile cache)
        # is the follow-up that closes the satellite-anchoring half
        # of the per-frame loop.
        "mode: replay\n"
        "replay:\n"
        "  pace: asap\n"
        "  target_fc_dialect: ardupilot_plane\n"
        "c1_vio:\n"
        "  strategy: klt_ransac\n"
        "c4_pose:\n"
        "  enabled: false\n"
        "c5_state:\n"
        "  strategy: eskf\n"
    )

    output_path = work_dir / "estimator_output.jsonl"

    ground_truth = ground_truth_full

    return DerkachiReplayInputs(
        video_path=video_path,
        tlog_path=tlog_path,
        calibration_path=_calibration_path(),
        config_path=config_path,
        signing_key_path=signing_key_path,
        output_path=output_path,
        ground_truth=ground_truth,
    )


@dataclass(frozen=True)
class ReplayRunResult:
    """Outcome of a single ``gps-denied-replay`` subprocess run."""

    returncode: int
    stdout: str
    stderr: str
    output_path: Path
    wall_clock_s: float


@pytest.fixture
def replay_runner(derkachi_replay_inputs: DerkachiReplayInputs) -> Any:
    """Return a callable that invokes the ``gps-denied-replay`` console-script.

    The callable accepts keyword overrides for ``pace``,
    ``time_offset_ms``, and ``skip_auto_sync`` (AZ-611); everything
    else is taken from ``derkachi_replay_inputs``. Output is written
    to a fresh path per invocation so determinism comparisons (AC-5)
    get two independent files.

    Derkachi is a mid-flight fixture (no take-off spike) and the only
    motion the video detector sees in the first 60 s is camera shake
    and scenery change — neither tlog nor video can produce a
    reliable auto-sync signal. The synth tlog and the video share
    the same ``t=0`` anchor by construction (see
    ``_tlog_synth.py``), so the correct offset is exactly ``0``. The
    fixture defaults reflect that — heavy ACs pass
    ``time_offset_ms=0`` + ``skip_auto_sync=True`` so the run never
    touches the AC-9 validator that would otherwise reject the
    fixture's false-positive video motion onset.
    """

    binary = shutil.which("gps-denied-replay")
    if binary is None:
        venv_bin = Path(sys.executable).parent / "gps-denied-replay"
        if venv_bin.exists():
            binary = str(venv_bin)
    if binary is None:
        pytest.skip(
            "gps-denied-replay console-script not on PATH; "
            "install the package in the test venv"
        )

    invocation_count = {"n": 0}

    def _run(
        *,
        pace: str = "asap",
        time_offset_ms: int | None = 0,
        skip_auto_sync: bool = True,
        max_duration_s: float | None = None,
    ) -> ReplayRunResult:
        import time

        invocation_count["n"] += 1
        out_path = derkachi_replay_inputs.output_path.with_name(
            f"estimator_output_{invocation_count['n']}.jsonl"
        )
        argv = [
            binary,
            "--video",
            str(derkachi_replay_inputs.video_path),
            "--tlog",
            str(derkachi_replay_inputs.tlog_path),
            "--output",
            str(out_path),
            "--camera-calibration",
            str(derkachi_replay_inputs.calibration_path),
            "--config",
            str(derkachi_replay_inputs.config_path),
            "--mavlink-signing-key",
            str(derkachi_replay_inputs.signing_key_path),
            "--pace",
            pace,
        ]
        if time_offset_ms is not None:
            argv.extend(["--time-offset-ms", str(time_offset_ms)])
        if skip_auto_sync:
            argv.append("--skip-auto-sync")
        if max_duration_s is not None:
            argv.extend(["--max-duration-s", str(max_duration_s)])
        # Build-flag env vars required by the airborne factories for
        # the strategies the replay config selects (klt_ransac VIO +
        # ESKF state estimator). Both default OFF in the factory
        # gates — opt them in explicitly so the eager
        # `_build_c5_state_estimator_pair` and the lazy c1_vio
        # factory find their gating flags ON.
        run_env = {
            **os.environ,
            "BUILD_KLT_RANSAC": "ON",
            "BUILD_STATE_ESKF": "ON",
        }
        t0 = time.monotonic()
        completed = subprocess.run(
            argv,
            capture_output=True,
            text=True,
            timeout=180,
            env=run_env,
        )
        wall_s = time.monotonic() - t0
        return ReplayRunResult(
            returncode=completed.returncode,
            stdout=completed.stdout,
            stderr=completed.stderr,
            output_path=out_path,
            wall_clock_s=wall_s,
        )

    return _run


@pytest.fixture
def operator_pre_flight_setup(tmp_path: Path) -> Iterator[Path]:
    """Operator C12 pre-flight rehearsal stub.

    Per AZ-404's spec this fixture should run the operator's full
    C10/C11/C12 pre-flight against a ``mock-suite-sat-service``
    fixture and yield the populated cache directory. The current
    ``tests/fixtures/mock-suite-sat-service`` is a bootstrap stub
    (only ``GET /healthz`` per its README) — the full D-PROJ-2
    contract is not implemented. Until that ships, AC-8 (operator
    workflow rehearsal) is skipped at the test level; this fixture
    yields a placeholder cache directory so test bodies that
    request it can fail-fast with a documented reason rather than a
    surprise ImportError.
    """
    cache_dir = tmp_path / "operator_cache"
    cache_dir.mkdir()
    yield cache_dir