"""NFT-PERF-03 — Cold-start Time-To-First-Fix (AZ-430 / AC-NEW-1).

Tier-2 ONLY. N≥10 cold-start iterations; each measures
``t_first_emission − t_first_frame_arrival``; asserts:

* AC-3: ``p95(TTFF) ≤ 30 s``.
* AC-4: ``max(TTFF) ≤ 45 s``.

Per-iteration cleanup (fdr-output volume wipe + SITL cold-boot reload
+ SUT lifecycle restart) is owned by the Tier-2 Jetson harness
(AZ-444). The runner-side scenario here only consumes a fixture that
encodes the N captured ``(first_frame_arrival_ms, first_emission_ms)``
pairs.

Production dependency surfaced to AZ-595 / AZ-444: the
``E2E_NFT_PERF_03_TTFF_FIXTURE`` env var names a JSON file (absolute
path or relative to ``E2E_SITL_REPLAY_DIR``) with shape:

    {
      "iterations": [
        {
          "iteration_id": "iter-01",
          "first_frame_arrival_ms": 1234,
          "first_emission_ms": 16789
        },
        ...
      ]
    }

``first_emission_ms`` may be ``null`` for a timed-out iteration —
counted as ``missed_starts`` and treated as a budget breach.
"""

from __future__ import annotations

import json
import os
from pathlib import Path

import pytest

from runner.helpers import ttff_evaluator as te

TTFF_FIXTURE_ENV_VAR = "E2E_NFT_PERF_03_TTFF_FIXTURE"
TTFF_DEFAULT_FIXTURE_NAME = "nft_perf_03_ttff.json"


@pytest.mark.tier2_only
@pytest.mark.scenario_id("nft-perf-03")
@pytest.mark.traces_to("AC-NEW-1,AC-1,AC-2,AC-3,AC-4,AC-5")
def test_nft_perf_03_cold_start_ttff(
    fc_adapter: str,
    vio_strategy: str,
    evidence_dir,  # type: ignore[no-untyped-def]
    run_id: str,
    nfr_recorder,  # type: ignore[no-untyped-def]
    sitl_replay_ready: bool,
) -> None:
    """AC-3 + AC-4 + iteration-count gate across ``(fc_adapter, vio_strategy)``."""
    if not sitl_replay_ready:
        pytest.skip(
            "NFT-PERF-03 requires `E2E_SITL_REPLAY_DIR` to point at a "
            "prepared SITL replay fixture (AZ-595) containing N≥10 cold-start "
            "iterations. Pure-logic AC-3/AC-4 covered by "
            "e2e/_unit_tests/helpers/test_ttff_evaluator.py."
        )

    fixture_path = _resolve_ttff_fixture_path()
    if not fixture_path.is_file():
        pytest.fail(
            f"NFT-PERF-03: TTFF fixture not found at {fixture_path}. "
            f"`{TTFF_FIXTURE_ENV_VAR}` env var must point at a JSON file "
            "carrying N≥10 cold-start iteration records (see scenario "
            "docstring). Production dependency: AZ-595 + AZ-444."
        )

    iterations = _load_iterations(fixture_path)
    if not iterations:
        pytest.fail(
            f"NFT-PERF-03: TTFF fixture {fixture_path} contains zero "
            "iterations. AZ-430 requires N≥10."
        )

    report = te.evaluate(iterations)

    base = Path(evidence_dir) / "nft-perf-03" / f"{fc_adapter}-{vio_strategy}"
    te.write_csv_evidence(base.with_suffix(".csv"), report)
    te.write_per_iteration_csv(
        base.with_name(base.name + "-per-iter").with_suffix(".csv"),
        report,
    )

    nfr_recorder.record_metric(
        "nft_perf_03.iteration_count", float(report.iteration_count), ac_id="AC-3"
    )
    nfr_recorder.record_metric(
        "nft_perf_03.missed_starts", float(report.missed_starts)
    )
    if report.p50_s is not None:
        nfr_recorder.record_metric("nft_perf_03.ttff_s_p50", float(report.p50_s))
    if report.p95_s is not None:
        nfr_recorder.record_metric(
            "nft_perf_03.ttff_s_p95", float(report.p95_s), ac_id="AC-3"
        )
    if report.max_s is not None:
        nfr_recorder.record_metric(
            "nft_perf_03.ttff_s_max", float(report.max_s), ac_id="AC-4"
        )

    assert report.passes_iteration_count, (
        f"AC-1 (iteration count): collected only {report.iteration_count} "
        f"iterations; require N ≥ {report.min_iteration_count}"
    )
    assert report.passes_p95, (
        f"AC-3: p95(TTFF) = {report.p95_s} s > budget "
        f"{report.p95_budget_s} s "
        f"(missed_starts={report.missed_starts})"
    )
    assert report.passes_max, (
        f"AC-4: max(TTFF) = {report.max_s} s > budget "
        f"{report.max_budget_s} s "
        f"(missed_starts={report.missed_starts})"
    )


def _resolve_ttff_fixture_path() -> Path:
    raw = os.environ.get(TTFF_FIXTURE_ENV_VAR, "").strip()
    from runner.helpers import sitl_observer

    root = sitl_observer.replay_dir()
    if not raw:
        if root is None:
            return Path(f"<{TTFF_FIXTURE_ENV_VAR}-unset>")
        return root / TTFF_DEFAULT_FIXTURE_NAME
    path = Path(raw)
    if not path.is_absolute() and root is not None:
        path = root / path
    return path


def _load_iterations(fixture_path: Path) -> list[te.ColdStartIteration]:
    payload = json.loads(fixture_path.read_text())
    raw = payload.get("iterations") if isinstance(payload, dict) else None
    if not isinstance(raw, list):
        pytest.fail(
            f"NFT-PERF-03: TTFF fixture {fixture_path} must be a JSON object "
            f'with key "iterations" → list; got top-level '
            f"type={type(payload).__name__}"
        )
    parsed: list[te.ColdStartIteration] = []
    for idx, entry in enumerate(raw):
        if not isinstance(entry, dict):
            pytest.fail(
                f"NFT-PERF-03: iterations[{idx}] in {fixture_path} must be "
                f"an object; got {type(entry).__name__}"
            )
        iter_id = str(entry.get("iteration_id") or f"iter-{idx:02d}")
        try:
            arrival = int(entry["first_frame_arrival_ms"])
        except (KeyError, TypeError, ValueError) as exc:
            pytest.fail(
                f"NFT-PERF-03: iterations[{idx}].first_frame_arrival_ms "
                f"in {fixture_path} must be an int ms timestamp: {exc}"
            )
        first_emission_raw = entry.get("first_emission_ms")
        first_emission: int | None
        if first_emission_raw is None:
            first_emission = None
        else:
            try:
                first_emission = int(first_emission_raw)
            except (TypeError, ValueError) as exc:
                pytest.fail(
                    f"NFT-PERF-03: iterations[{idx}].first_emission_ms "
                    f"in {fixture_path} must be int or null: {exc}"
                )
        try:
            parsed.append(
                te.measure_iteration(
                    iter_id,
                    first_frame_arrival_ms=arrival,
                    first_emission_ms=first_emission,
                )
            )
        except ValueError as exc:
            pytest.fail(
                f"NFT-PERF-03: iterations[{idx}] in {fixture_path} rejected: {exc}"
            )
    return parsed