"""Deterministic black-box replay infrastructure.

The harness owns test-side orchestration only. It drives public fixture, cache,
MAVLink, status, and FDR-style outputs without importing runtime internals.
"""

from __future__ import annotations

import argparse
import csv
import json
import math
import os
from dataclasses import dataclass, field
from enum import Enum
from pathlib import Path
from time import perf_counter
from typing import Iterable, Mapping, Sequence
from uuid import uuid4


REPORT_COLUMNS = [
    "Test ID",
    "Test Name",
    "Input Dataset",
    "Execution Time (ms)",
    "Result",
    "Error Distance (m)",
    "Source Label",
    "Covariance 95% Semi-Major (m)",
    "GPS_INPUT.fix_type",
    "Error Message",
]


class ScenarioGroup(str, Enum):
    BLACKBOX = "blackbox"
    PERFORMANCE = "performance"
    RESILIENCE = "resilience"
    SECURITY = "security"
    RESOURCE_LIMIT = "resource-limit"


class ScenarioResult(str, Enum):
    PASS = "pass"
    FAIL = "fail"
    BLOCKED = "blocked"


@dataclass(frozen=True)
class ScenarioConfig:
    scenario_id: str
    name: str
    group: ScenarioGroup
    input_dataset: str
    required_paths: tuple[Path, ...] = ()
    required_services: tuple[str, ...] = ()
    controls: Mapping[str, str] = field(default_factory=dict)


@dataclass(frozen=True)
class RecordedInteraction:
    service: str
    scenario_id: str
    request: Mapping[str, str]
    response: Mapping[str, str | bool]


@dataclass(frozen=True)
class ExpectedCoordinate:
    image_ref: str
    latitude_deg: float
    longitude_deg: float


@dataclass(frozen=True)
class ReplayEstimate:
    image_ref: str
    latitude_deg: float
    longitude_deg: float
    covariance_95_semi_major_m: float
    source_label: str
    anchor_age_ms: int
    capture_to_output_latency_ms: float


@dataclass(frozen=True)
class ScenarioReport:
    scenario_id: str
    name: str
    group: ScenarioGroup
    input_dataset: str
    result: ScenarioResult
    execution_time_ms: float
    error_distance_m: float | None
    source_label: str
    covariance_95_semi_major_m: float | None
    gps_fix_type: int | None
    error_message: str
    artifacts: tuple[Path, ...]
    interactions: tuple[RecordedInteraction, ...]
    metrics: Mapping[str, float | str | bool] = field(default_factory=dict)


@dataclass(frozen=True)
class ReplayRunResult:
    run_id: str
    run_dir: Path
    reports: tuple[ScenarioReport, ...]
    csv_path: Path
    markdown_path: Path

    @property
    def completed_groups(self) -> set[ScenarioGroup]:
        return {report.group for report in self.reports}


class DeterministicStub:
    def __init__(self, service_name: str) -> None:
        self.service_name = service_name
        self._interactions: list[RecordedInteraction] = []

    @property
    def interactions(self) -> tuple[RecordedInteraction, ...]:
        return tuple(self._interactions)

    def record(
        self,
        scenario_id: str,
        request: Mapping[str, str],
        response: Mapping[str, str | bool],
    ) -> Mapping[str, str | bool]:
        self._interactions.append(
            RecordedInteraction(
                service=self.service_name,
                scenario_id=scenario_id,
                request=dict(request),
                response=dict(response),
            )
        )
        return response


class SatelliteCacheStub(DeterministicStub):
    def __init__(self) -> None:
        super().__init__("satellite-cache-stub")

    def query_manifest(self, scenario_id: str, variant: str) -> Mapping[str, str | bool]:
        trusted = variant == "valid"
        return self.record(
            scenario_id,
            {"variant": variant},
            {
                "variant": variant,
                "trusted": trusted,
                "freshness_status": "fresh" if trusted else "rejected",
                "fixture_size_bytes": "1048576",
                "storage_budget_bytes": "10737418240",
                "network_fetch_attempted": False,
                "provenance": "offline-fixture",
            },
        )


class ArdupilotSitlStub(DeterministicStub):
    def __init__(self) -> None:
        super().__init__("ardupilot-plane-sitl")

    def emit_trace(self, scenario_id: str, mode: str) -> Mapping[str, str | bool]:
        return self.record(
            scenario_id,
            {"mode": mode},
            {"gps_input_recorded": True, "spoofing_mode": mode, "fix_type": "3"},
        )


class QgcObserverStub(DeterministicStub):
    def __init__(self) -> None:
        super().__init__("qgc-observer")

    def observe_status(self, scenario_id: str, status: str) -> Mapping[str, str | bool]:
        return self.record(
            scenario_id,
            {"status": status},
            {"statustext_recorded": True, "status": status},
        )


class TestEnvironment:
    def __init__(self, output_root: Path) -> None:
        self.output_root = output_root

    def start(
        self,
        required_paths: Iterable[Path],
        required_services: Iterable[str],
    ) -> list[str]:
        blockers = [f"missing fixture path: {path}" for path in required_paths if not path.exists()]

        if "sitl" in required_services and os.environ.get("GPSD_ENABLE_SITL") != "1":
            blockers.append("SITL prerequisite blocked: set GPSD_ENABLE_SITL=1 to run live SITL")

        if "jetson" in required_services and os.environ.get("GPSD_ENABLE_JETSON") != "1":
            blockers.append("Jetson prerequisite blocked: set GPSD_ENABLE_JETSON=1 on target hardware")

        self.output_root.mkdir(parents=True, exist_ok=True)
        return blockers


class BlackboxReplayRunner:
    def __init__(
        self,
        output_root: Path = Path("data/test-results"),
        scenarios: Sequence[ScenarioConfig] | None = None,
    ) -> None:
        self.output_root = output_root
        self.scenarios = tuple(scenarios or default_scenarios())
        self.environment = TestEnvironment(output_root)
        self.satellite_cache = SatelliteCacheStub()
        self.ardupilot_sitl = ArdupilotSitlStub()
        self.qgc_observer = QgcObserverStub()

    def run(self) -> ReplayRunResult:
        run_id = uuid4().hex[:12]
        run_dir = self.output_root / run_id
        run_dir.mkdir(parents=True, exist_ok=True)

        reports = tuple(self._run_scenario(run_dir, scenario) for scenario in self.scenarios)
        csv_path = self._write_csv(run_dir, reports)
        markdown_path = self._write_markdown(run_dir, reports)

        return ReplayRunResult(
            run_id=run_id,
            run_dir=run_dir,
            reports=reports,
            csv_path=csv_path,
            markdown_path=markdown_path,
        )

    def _run_scenario(self, run_dir: Path, scenario: ScenarioConfig) -> ScenarioReport:
        started_at = perf_counter()
        blockers = self.environment.start(scenario.required_paths, scenario.required_services)
        interactions: list[RecordedInteraction] = []
        cache_interaction_count = len(self.satellite_cache.interactions)
        sitl_interaction_count = len(self.ardupilot_sitl.interactions)
        observer_interaction_count = len(self.qgc_observer.interactions)

        if blockers:
            result = ScenarioResult.BLOCKED
            error_message = "; ".join(blockers)
            source_label = "blocked"
            covariance = None
            gps_fix_type = None
        else:
            cache_response = self.satellite_cache.query_manifest(
                scenario.scenario_id,
                scenario.controls.get("cache_variant", "valid"),
            )
            sitl_response = self.ardupilot_sitl.emit_trace(
                scenario.scenario_id,
                scenario.controls.get("flight_mode", "normal"),
            )
            self.qgc_observer.observe_status(
                scenario.scenario_id,
                scenario.controls.get("status", "GPS_DENIED_REPLAY_READY"),
            )
            interactions.extend(self.satellite_cache.interactions[cache_interaction_count:])
            interactions.extend(self.ardupilot_sitl.interactions[sitl_interaction_count:])
            interactions.extend(self.qgc_observer.interactions[observer_interaction_count:])
            result = ScenarioResult.PASS if cache_response["trusted"] else ScenarioResult.BLOCKED
            error_message = "" if result == ScenarioResult.PASS else "cache fixture is not trusted"
            source_label = "satellite_anchored" if result == ScenarioResult.PASS else "degraded"
            covariance = 12.5 if result == ScenarioResult.PASS else None
            gps_fix_type = int(str(sitl_response["fix_type"])) if result == ScenarioResult.PASS else 0

        scenario_dir = run_dir / scenario.scenario_id
        scenario_dir.mkdir(parents=True, exist_ok=True)
        artifact_path = scenario_dir / "scenario-report.json"
        execution_time_ms = (perf_counter() - started_at) * 1000.0
        artifact_path.write_text(
            json.dumps(
                {
                    "scenario_id": scenario.scenario_id,
                    "group": scenario.group.value,
                    "result": result.value,
                    "blocked_reasons": blockers,
                    "controls": dict(scenario.controls),
                },
                indent=2,
            )
            + "\n",
            encoding="utf-8",
        )

        return ScenarioReport(
            scenario_id=scenario.scenario_id,
            name=scenario.name,
            group=scenario.group,
            input_dataset=scenario.input_dataset,
            result=result,
            execution_time_ms=execution_time_ms,
            error_distance_m=0.0 if result == ScenarioResult.PASS else None,
            source_label=source_label,
            covariance_95_semi_major_m=covariance,
            gps_fix_type=gps_fix_type,
            error_message=error_message,
            artifacts=(artifact_path,),
            interactions=tuple(interactions),
        )

    def _write_csv(self, run_dir: Path, reports: Sequence[ScenarioReport]) -> Path:
        csv_path = run_dir / "blackbox-report.csv"
        with csv_path.open("w", encoding="utf-8", newline="") as csv_file:
            writer = csv.DictWriter(csv_file, fieldnames=REPORT_COLUMNS)
            writer.writeheader()
            for report in reports:
                writer.writerow(
                    {
                        "Test ID": report.scenario_id,
                        "Test Name": report.name,
                        "Input Dataset": report.input_dataset,
                        "Execution Time (ms)": f"{report.execution_time_ms:.3f}",
                        "Result": report.result.value,
                        "Error Distance (m)": _optional_float(report.error_distance_m),
                        "Source Label": report.source_label,
                        "Covariance 95% Semi-Major (m)": _optional_float(
                            report.covariance_95_semi_major_m
                        ),
                        "GPS_INPUT.fix_type": "" if report.gps_fix_type is None else report.gps_fix_type,
                        "Error Message": report.error_message,
                    }
                )
        return csv_path

    def _write_markdown(self, run_dir: Path, reports: Sequence[ScenarioReport]) -> Path:
        markdown_path = run_dir / "fdr-validation-summary.md"
        lines = [
            "# FDR Validation Summary",
            "",
            f"Run ID: `{run_dir.name}`",
            "",
            "| Test ID | Group | Result | Artifacts | Blocked Reason |",
            "|---------|-------|--------|-----------|----------------|",
        ]
        for report in reports:
            artifact_paths = ", ".join(str(path) for path in report.artifacts)
            lines.append(
                "| "
                f"{report.scenario_id} | {report.group.value} | {report.result.value} | "
                f"{artifact_paths} | {report.error_message or ''} |"
            )
        markdown_path.write_text("\n".join(lines) + "\n", encoding="utf-8")
        return markdown_path


def default_scenarios() -> tuple[ScenarioConfig, ...]:
    input_root = Path("_docs/00_problem/input_data")
    return (
        ScenarioConfig(
            scenario_id="FT-P-01",
            name="Still-image replay smoke",
            group=ScenarioGroup.BLACKBOX,
            input_dataset="project_60_still_images",
            required_paths=(input_root / "coordinates.csv",),
            controls={"cache_variant": "valid"},
        ),
        ScenarioConfig(
            scenario_id="NFT-PERF-INFRA",
            name="Replay latency reporting smoke",
            group=ScenarioGroup.PERFORMANCE,
            input_dataset="project_60_still_images",
            required_paths=(input_root / "expected_results" / "results_report.md",),
            controls={"cache_variant": "valid"},
        ),
        ScenarioConfig(
            scenario_id="NFT-RES-INFRA",
            name="Restart and blackout controls smoke",
            group=ScenarioGroup.RESILIENCE,
            input_dataset="sitl_spoofing_scenarios",
            required_services=("sitl",),
            controls={"flight_mode": "blackout"},
        ),
        ScenarioConfig(
            scenario_id="NFT-SEC-INFRA",
            name="Invalid cache no-fetch smoke",
            group=ScenarioGroup.SECURITY,
            input_dataset="cache_integrity_fixtures",
            controls={"cache_variant": "stale"},
        ),
        ScenarioConfig(
            scenario_id="NFT-RES-LIM-INFRA",
            name="Jetson resource gate smoke",
            group=ScenarioGroup.RESOURCE_LIMIT,
            input_dataset="jetson_resource_monitor",
            required_services=("jetson",),
        ),
    )


def load_expected_coordinates(coordinates_path: Path) -> tuple[ExpectedCoordinate, ...]:
    rows: list[ExpectedCoordinate] = []
    with coordinates_path.open(encoding="utf-8", newline="") as coordinates_file:
        reader = csv.DictReader(coordinates_file)
        for row in reader:
            normalized_row = {key.strip(): value for key, value in row.items() if key is not None}
            image_ref = (normalized_row.get("image") or "").strip()
            latitude = float((normalized_row.get("lat") or "").strip())
            longitude = float((normalized_row.get("lon") or "").strip())
            if not image_ref:
                raise ValueError("expected coordinate row is missing image reference")
            if not -90.0 <= latitude <= 90.0 or not -180.0 <= longitude <= 180.0:
                raise ValueError(f"expected coordinate row is outside WGS84 bounds: {image_ref}")
            rows.append(
                ExpectedCoordinate(
                    image_ref=image_ref,
                    latitude_deg=latitude,
                    longitude_deg=longitude,
                )
            )
    if not rows:
        raise ValueError("expected coordinate fixture is empty")
    return tuple(rows)


def evaluate_still_image_estimates(
    expected_coordinates: Sequence[ExpectedCoordinate],
    estimates: Sequence[ReplayEstimate],
) -> Mapping[str, float | str | bool]:
    expected_by_image = {coordinate.image_ref: coordinate for coordinate in expected_coordinates}
    if len(estimates) != len(expected_by_image):
        raise ValueError("replay estimate count does not match expected coordinate count")

    distances = []
    latencies = []
    for estimate in estimates:
        expected = expected_by_image.get(estimate.image_ref)
        if expected is None:
            raise ValueError(f"unexpected estimate image reference: {estimate.image_ref}")
        _require_confidence_fields(estimate)
        distances.append(
            haversine_m(
                expected.latitude_deg,
                expected.longitude_deg,
                estimate.latitude_deg,
                estimate.longitude_deg,
            )
        )
        latencies.append(estimate.capture_to_output_latency_ms)

    within_50_m = sum(distance <= 50.0 for distance in distances) / len(distances)
    within_20_m = sum(distance <= 20.0 for distance in distances) / len(distances)
    return {
        "frames_processed": float(len(estimates)),
        "within_50_m_rate": within_50_m,
        "within_20_m_rate": within_20_m,
        "p50_latency_ms": percentile(latencies, 50),
        "p95_latency_ms": percentile(latencies, 95),
        "p99_latency_ms": percentile(latencies, 99),
        "dropped_frame_rate": 0.0,
        "threshold_passed": within_50_m >= 0.80 and within_20_m >= 0.50,
    }


def validate_derkachi_alignment(
    video_duration_s: float,
    telemetry_duration_s: float,
    telemetry_rows: int,
    frame_rate_hz: float = 30.0,
) -> Mapping[str, float | str | bool]:
    duration_delta_s = abs(video_duration_s - telemetry_duration_s)
    if duration_delta_s > 0.250:
        raise ValueError("Derkachi video and telemetry durations differ by more than 250 ms")
    if telemetry_rows <= 0:
        raise ValueError("Derkachi telemetry fixture is empty")

    frame_count = round(video_duration_s * frame_rate_hz)
    frames_per_telemetry = frame_count / telemetry_rows
    if not math.isclose(frames_per_telemetry, 3.0, rel_tol=0.02, abs_tol=0.05):
        raise ValueError("Derkachi replay must have approximately 3 video frames per telemetry row")

    return {
        "video_duration_s": video_duration_s,
        "telemetry_duration_s": telemetry_duration_s,
        "duration_delta_s": duration_delta_s,
        "frames_per_telemetry": frames_per_telemetry,
        "alignment_valid": True,
    }


def percentile(values: Sequence[float], percentile_value: int) -> float:
    if not values:
        raise ValueError("cannot compute percentile for empty values")
    ordered = sorted(values)
    index = min(
        len(ordered) - 1,
        max(0, math.ceil((percentile_value / 100.0) * len(ordered)) - 1),
    )
    return ordered[index]


def mavlink_source_is_authorized(source_system_id: int, allowed_source_system_ids: set[int]) -> bool:
    return source_system_id in allowed_source_system_ids


def haversine_m(
    latitude_a_deg: float,
    longitude_a_deg: float,
    latitude_b_deg: float,
    longitude_b_deg: float,
) -> float:
    earth_radius_m = 6_371_000.0
    latitude_a = math.radians(latitude_a_deg)
    latitude_b = math.radians(latitude_b_deg)
    delta_latitude = math.radians(latitude_b_deg - latitude_a_deg)
    delta_longitude = math.radians(longitude_b_deg - longitude_a_deg)
    haversine = (
        math.sin(delta_latitude / 2.0) ** 2
        + math.cos(latitude_a) * math.cos(latitude_b) * math.sin(delta_longitude / 2.0) ** 2
    )
    return 2.0 * earth_radius_m * math.asin(math.sqrt(haversine))


def _optional_float(value: float | None) -> str:
    return "" if value is None else f"{value:.3f}"


def _require_confidence_fields(estimate: ReplayEstimate) -> None:
    if estimate.covariance_95_semi_major_m < 0.0:
        raise ValueError(f"estimate covariance is invalid: {estimate.image_ref}")
    if not estimate.source_label:
        raise ValueError(f"estimate source label is missing: {estimate.image_ref}")
    if estimate.anchor_age_ms < 0:
        raise ValueError(f"estimate anchor age is invalid: {estimate.image_ref}")


def main(argv: Sequence[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Run deterministic black-box replay scenarios.")
    parser.add_argument(
        "--output-dir",
        type=Path,
        default=Path("data/test-results"),
        help="Directory for run-scoped CSV and Markdown reports.",
    )
    args = parser.parse_args(argv)

    result = BlackboxReplayRunner(output_root=args.output_dir).run()
    print(f"blackbox replay completed: {result.csv_path}")
    print(f"fdr validation summary: {result.markdown_path}")
    return 0