#!/usr/bin/env python3
"""Resume-state helpers for SmartGridBench GCP fallback runs.

The shell runner owns process orchestration. This helper owns the fiddly,
testable parts of resume: trial classification, latency-row dedupe, atomic
finalization, and manifest events.
"""

from __future__ import annotations

import argparse
import glob
import hashlib
import importlib.metadata
import json
import os
import re
import shlex
import subprocess
import sys
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

_REPO_ROOT = Path(__file__).resolve().parent.parent
if str(_REPO_ROOT) not in sys.path:
    sys.path.insert(0, str(_REPO_ROOT))


def _now_iso() -> str:
    return datetime.now(timezone.utc).isoformat()


def _posix(path: Path | str) -> str:
    return Path(path).as_posix()


def _norm(path: Path | str) -> str:
    return os.path.normpath(_posix(path))


def _shell_bool(value: bool) -> str:
    return "1" if value else "0"


def _emit_shell(values: dict[str, Any]) -> None:
    for key, value in values.items():
        print(f"{key}={shlex.quote(str(value))}")


def _package_version(name: str) -> str | None:
    try:
        return importlib.metadata.version(name)
    except importlib.metadata.PackageNotFoundError:
        return None


def _command_output(args: list[str]) -> str | None:
    try:
        return subprocess.check_output(
            args,
            stderr=subprocess.STDOUT,
            text=True,
            timeout=10,
        ).strip()
    except Exception:
        return None


def collect_runtime_versions() -> dict[str, Any]:
    cuda_visible = os.environ.get("CUDA_VISIBLE_DEVICES")
    gpu_id = (cuda_visible or "0").split(",")[0].strip() or "0"
    versions: dict[str, Any] = {
        "vllm_version": _package_version("vllm"),
        "torch_version": _package_version("torch"),
        "cuda_visible_devices": cuda_visible,
        "nvidia_driver_version": None,
        "cuda_version": None,
        "nvidia_smi_query": None,
    }
    raw = _command_output(
        [
            "nvidia-smi",
            f"--id={gpu_id}",
            "--query-gpu=driver_version,cuda_version",
            "--format=csv,noheader",
        ]
    )
    if raw:
        versions["nvidia_smi_query"] = raw
        first_row = raw.splitlines()[0]
        parts = [part.strip() for part in first_row.split(",")]
        if parts:
            versions["nvidia_driver_version"] = parts[0] or None
        if len(parts) > 1:
            versions["cuda_version"] = parts[1] or None
    if versions["nvidia_driver_version"] is None:
        driver = _command_output(
            [
                "nvidia-smi",
                f"--id={gpu_id}",
                "--query-gpu=driver_version",
                "--format=csv,noheader",
            ]
        )
        if driver:
            versions["nvidia_driver_version"] = driver.splitlines()[0].strip() or None
    if versions["cuda_version"] is None:
        smi = _command_output(["nvidia-smi"])
        if smi:
            match = re.search(r"CUDA Version:\s*([0-9.]+)", smi)
            if match:
                versions["cuda_version"] = match.group(1)
    return versions


def _load_json_object(path: Path) -> tuple[dict[str, Any] | None, str | None]:
    if not path.exists():
        return None, "missing_json"
    try:
        if path.stat().st_size == 0:
            return None, "zero_byte_json"
        payload = json.loads(path.read_text(encoding="utf-8"))
    except json.JSONDecodeError:
        return None, "invalid_json"
    except OSError as exc:
        return None, f"read_error:{exc}"
    if not isinstance(payload, dict):
        return None, "non_object_json"
    return payload, None


def _scenario_payload(path: Path) -> dict[str, Any]:
    payload = json.loads(path.read_text(encoding="utf-8"))
    if not isinstance(payload, dict):
        raise ValueError(f"scenario is not a JSON object: {path}")
    return payload


def _scenario_basename(path: Path) -> str:
    return path.stem


def _expand_scenario_glob(scenario_glob: str) -> list[Path]:
    """Expand either one glob pattern or a shell-style list of scenario paths."""
    tokens = shlex.split(scenario_glob)
    if not tokens:
        tokens = [scenario_glob]
    paths: list[Path] = []
    seen: set[str] = set()
    for token in tokens:
        for match in sorted(glob.glob(token)):
            key = _norm(match)
            if key in seen:
                continue
            paths.append(Path(match))
            seen.add(key)
    return paths


def _step_failed(step: dict[str, Any]) -> bool:
    if step.get("success") is False:
        return True
    if step.get("error"):
        return True
    response = step.get("response")
    return isinstance(response, dict) and bool(response.get("error"))


def derive_success(data: dict[str, Any]) -> bool | None:
    raw = data.get("success")
    if isinstance(raw, bool):
        return raw
    steps = data.get("history") or data.get("trajectory") or []
    if not steps and not data.get("answer"):
        return None
    for step in steps:
        if isinstance(step, dict) and _step_failed(step):
            return False
    return bool(data.get("answer"))


def _scenario_id_matches(
    payload: dict[str, Any],
    scenario: dict[str, Any],
) -> bool:
    embedded = payload.get("scenario")
    if not isinstance(embedded, dict):
        return True
    expected_id = scenario.get("id")
    actual_id = embedded.get("id")
    return not expected_id or not actual_id or expected_id == actual_id


def _latency_records(latency_file: Path) -> list[dict[str, Any]]:
    if not latency_file.exists():
        return []
    records: list[dict[str, Any]] = []
    for line in latency_file.read_text(encoding="utf-8").splitlines():
        if not line.strip():
            continue
        try:
            payload = json.loads(line)
        except json.JSONDecodeError:
            continue
        if isinstance(payload, dict):
            records.append(payload)
    return records


def _record_matches_identity(
    record: dict[str, Any],
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
) -> bool:
    if int(record.get("trial_index", -1)) != int(trial_index):
        return False
    output = record.get("output_path")
    if output and _norm(output) != _norm(output_path):
        return False
    scenario = record.get("scenario_file")
    return not scenario or _norm(scenario) == _norm(scenario_file)


def _matching_latency_rows(
    records: list[dict[str, Any]],
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
) -> list[dict[str, Any]]:
    return [
        record
        for record in records
        if _record_matches_identity(record, scenario_file, trial_index, output_path)
    ]


def _rows_conflict(rows: list[dict[str, Any]]) -> bool:
    if len(rows) < 2:
        return False
    normalized = {
        json.dumps(row, sort_keys=True, separators=(",", ":")) for row in rows
    }
    return len(normalized) > 1


def _candidate_trial_paths(
    run_dir: Path,
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
) -> list[Path]:
    run_label = f"{_scenario_basename(scenario_file)}_run{trial_index:02d}.json"
    candidates = [output_path]
    candidates.extend(sorted(run_dir.glob(f"*_{run_label}")))
    seen: set[str] = set()
    deduped: list[Path] = []
    for candidate in candidates:
        key = str(candidate)
        if key not in seen:
            deduped.append(candidate)
            seen.add(key)
    return deduped


def classify_trial(
    *,
    run_dir: Path,
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
    latency_file: Path,
    require_latency: bool,
) -> dict[str, Any]:
    scenario = _scenario_payload(scenario_file)
    latency_records = _latency_records(latency_file)
    incomplete_reasons: list[str] = []
    saw_candidate = False

    for candidate in _candidate_trial_paths(
        run_dir, scenario_file, trial_index, output_path
    ):
        if not candidate.exists():
            continue
        saw_candidate = True
        payload, error = _load_json_object(candidate)
        if error is not None or payload is None:
            incomplete_reasons.append(error or "invalid_json")
            continue
        if not _scenario_id_matches(payload, scenario):
            incomplete_reasons.append("scenario_identity_conflict")
            continue
        success = derive_success(payload)
        if success is None:
            incomplete_reasons.append("success_not_derivable")
            continue
        rows = _matching_latency_rows(
            latency_records, scenario_file, trial_index, candidate
        )
        if require_latency:
            if not rows:
                incomplete_reasons.append("missing_latency")
                continue
            if _rows_conflict(rows):
                incomplete_reasons.append("duplicate_conflicting_latency")
                continue
        return {
            "state": "complete_success" if success else "complete_failure",
            "complete": True,
            "success": success,
            "output_path": _posix(candidate),
            "reason": "terminal_trial",
            "latency_rows": len(rows),
        }

    stdout_candidates = [
        path
        for path in run_dir.glob(
            f"*_{_scenario_basename(scenario_file)}_run{trial_index:02d}.json.stdout"
        )
        if path.exists()
    ]
    if stdout_candidates and not saw_candidate:
        incomplete_reasons.append("dangling_stdout")

    return {
        "state": "incomplete",
        "complete": False,
        "success": False,
        "output_path": _posix(output_path),
        "reason": ",".join(sorted(set(incomplete_reasons))) or "missing_json",
        "latency_rows": 0,
    }


def validate_run_artifacts(
    *,
    run_dir: Path,
    scenario_glob: str,
    trials: int,
    run_name: str = "",
    require_latency: bool = True,
) -> dict[str, Any]:
    scenario_files = _expand_scenario_glob(scenario_glob)
    expected = len(scenario_files) * int(trials)
    complete = 0
    success = 0
    failure = 0
    missing: list[dict[str, Any]] = []
    latency_file = run_dir / "latencies.jsonl"

    if expected == 0:
        return {
            "valid": False,
            "expected": 0,
            "complete": 0,
            "success": 0,
            "failure": 0,
            "missing": [],
            "reason": "no_expected_trials",
        }

    for scenario_file in scenario_files:
        basename = _scenario_basename(scenario_file)
        for trial_index in range(1, int(trials) + 1):
            output_name = f"{basename}_run{trial_index:02d}.json"
            if run_name:
                output_name = f"{run_name}_{output_name}"
            result = classify_trial(
                run_dir=run_dir,
                scenario_file=scenario_file,
                trial_index=trial_index,
                output_path=run_dir / output_name,
                latency_file=latency_file,
                require_latency=require_latency,
            )
            if result["complete"]:
                complete += 1
                if result["success"]:
                    success += 1
                else:
                    failure += 1
                continue
            missing.append(
                {
                    "scenario_file": _posix(scenario_file),
                    "trial_index": trial_index,
                    "reason": result["reason"],
                    "output_path": result["output_path"],
                }
            )

    valid = complete == expected
    return {
        "valid": valid,
        "expected": expected,
        "complete": complete,
        "success": success,
        "failure": failure,
        "missing": missing,
        "reason": "ok" if valid else "incomplete_trajectory_artifacts",
    }


def _sha256(path: Path) -> str | None:
    if not path.exists() or not path.is_file():
        return None
    h = hashlib.sha256()
    with path.open("rb") as fh:
        for chunk in iter(lambda: fh.read(1024 * 1024), b""):
            h.update(chunk)
    return h.hexdigest()


def write_manifest_event(
    *,
    manifest_file: Path,
    state: str,
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
    run_name: str,
    reason: str = "",
    batch_id: str = "",
    latency_seconds: float | None = None,
    return_code: int | None = None,
    started_at: str = "",
    finished_at: str = "",
    extra: dict[str, Any] | None = None,
) -> None:
    manifest_file.parent.mkdir(parents=True, exist_ok=True)
    payload: dict[str, Any] = {
        "schema_version": 1,
        "batch_id": batch_id or None,
        "run_name": run_name,
        "event": "trial_resume_state",
        "state": state,
        "reason": reason or None,
        "scenario_file": _posix(scenario_file),
        "scenario_basename": _scenario_basename(scenario_file),
        "trial_index": int(trial_index),
        "output_path": _posix(output_path),
        "latency_seconds": latency_seconds,
        "return_code": return_code,
        "started_at": started_at or None,
        "finished_at": finished_at or _now_iso(),
        "compute_provider": os.environ.get("SMARTGRID_COMPUTE_PROVIDER"),
        "compute_zone": os.environ.get("SMARTGRID_COMPUTE_ZONE"),
        "compute_instance": os.environ.get("SMARTGRID_COMPUTE_INSTANCE"),
        "gpu_type": os.environ.get("GPU_TYPE"),
        "runtime_versions": collect_runtime_versions(),
    }
    if extra:
        payload.update(extra)
    with manifest_file.open("a", encoding="utf-8") as fh:
        fh.write(json.dumps(payload, sort_keys=True) + "\n")


def preserve_incomplete_output(output_path: Path) -> Path | None:
    if not output_path.exists():
        return None
    suffix = datetime.now(timezone.utc).strftime("%Y%m%dT%H%M%SZ")
    preserved = output_path.with_name(f"{output_path.name}.incomplete.{suffix}")
    output_path.replace(preserved)
    return preserved


def _apply_final_answer_guards(payload: dict[str, Any]) -> None:
    try:
        from scripts.mitigation_guards import (  # type: ignore
            apply_explicit_fault_risk_adjudication,
            apply_missing_evidence_final_answer_guard,
            env_flag_enabled,
        )
    except ImportError:
        return
    apply_missing_evidence_final_answer_guard(
        payload,
        enabled=env_flag_enabled(os.environ.get("ENABLE_MISSING_EVIDENCE_GUARD")),
    )
    if "fault_risk_adjudication" not in payload:
        apply_explicit_fault_risk_adjudication(
            payload,
            enabled=env_flag_enabled(
                os.environ.get("ENABLE_EXPLICIT_FAULT_RISK_ADJUDICATION")
            ),
        )


def _upsert_latency_row(
    *,
    latency_file: Path,
    scenario_file: Path,
    trial_index: int,
    output_path: Path,
    latency_seconds: float,
) -> None:
    records = [
        row
        for row in _latency_records(latency_file)
        if not _record_matches_identity(row, scenario_file, trial_index, output_path)
    ]
    records.append(
        {
            "scenario_file": _posix(scenario_file),
            "trial_index": int(trial_index),
            "latency_seconds": latency_seconds,
            "output_path": _posix(output_path),
        }
    )
    latency_file.parent.mkdir(parents=True, exist_ok=True)
    tmp = latency_file.with_suffix(latency_file.suffix + ".tmp")
    tmp.write_text(
        "".join(json.dumps(record, sort_keys=True) + "\n" for record in records),
        encoding="utf-8",
    )
    tmp.replace(latency_file)


def finalize_trial(
    *,
    scenario_file: Path,
    trial_index: int,
    temp_output: Path,
    output_path: Path,
    latency_file: Path,
    manifest_file: Path,
    run_name: str,
    batch_id: str,
    start_epoch: float,
    end_epoch: float,
    return_code: int,
) -> dict[str, Any]:
    payload, error = _load_json_object(temp_output)
    if error is not None or payload is None:
        write_manifest_event(
            manifest_file=manifest_file,
            state="incomplete",
            scenario_file=scenario_file,
            trial_index=trial_index,
            output_path=output_path,
            run_name=run_name,
            reason=error or "invalid_json",
            batch_id=batch_id,
            return_code=return_code,
        )
        return {
            "state": "incomplete",
            "success": False,
            "reason": error or "invalid_json",
        }

    scenario = _scenario_payload(scenario_file)
    payload["scenario"] = scenario
    _apply_final_answer_guards(payload)
    success = derive_success(payload)
    if success is None:
        write_manifest_event(
            manifest_file=manifest_file,
            state="incomplete",
            scenario_file=scenario_file,
            trial_index=trial_index,
            output_path=output_path,
            run_name=run_name,
            reason="success_not_derivable",
            batch_id=batch_id,
            return_code=return_code,
        )
        return {
            "state": "incomplete",
            "success": False,
            "reason": "success_not_derivable",
        }
    payload["success"] = success

    output_path.parent.mkdir(parents=True, exist_ok=True)
    temp_output.write_text(
        json.dumps(payload, indent=2, default=str) + "\n", encoding="utf-8"
    )
    original_hash = _sha256(output_path)
    temp_hash = _sha256(temp_output)
    temp_output.replace(output_path)
    divergent: bool | None
    if original_hash is None:
        divergent = None
    else:
        divergent = original_hash != temp_hash
    latency_seconds = float(end_epoch) - float(start_epoch)
    _upsert_latency_row(
        latency_file=latency_file,
        scenario_file=scenario_file,
        trial_index=trial_index,
        output_path=output_path,
        latency_seconds=latency_seconds,
    )
    state = "complete_success" if success else "complete_failure"
    write_manifest_event(
        manifest_file=manifest_file,
        state=state,
        scenario_file=scenario_file,
        trial_index=trial_index,
        output_path=output_path,
        run_name=run_name,
        reason="trial_executed",
        batch_id=batch_id,
        latency_seconds=latency_seconds,
        return_code=return_code,
        extra={
            "original_output_sha256": original_hash,
            "final_output_sha256": temp_hash,
            "divergent": divergent,
        },
    )
    return {"state": state, "success": success, "reason": "trial_executed"}


def _build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(description=__doc__)
    sub = parser.add_subparsers(dest="command", required=True)

    status = sub.add_parser("trial-status-shell")
    status.add_argument("--run-dir", required=True, type=Path)
    status.add_argument("--scenario-file", required=True, type=Path)
    status.add_argument("--trial-index", required=True, type=int)
    status.add_argument("--output-path", required=True, type=Path)
    status.add_argument("--latency-file", required=True, type=Path)
    status.add_argument("--require-latency", action="store_true")

    preserve = sub.add_parser("preserve-incomplete")
    preserve.add_argument("--output-path", required=True, type=Path)
    preserve.add_argument("--manifest-file", required=True, type=Path)
    preserve.add_argument("--scenario-file", required=True, type=Path)
    preserve.add_argument("--trial-index", required=True, type=int)
    preserve.add_argument("--run-name", required=True)
    preserve.add_argument("--batch-id", default="")
    preserve.add_argument("--reason", default="rerun_preserved_incomplete")

    finalize = sub.add_parser("finalize-trial-shell")
    finalize.add_argument("--scenario-file", required=True, type=Path)
    finalize.add_argument("--trial-index", required=True, type=int)
    finalize.add_argument("--temp-output", required=True, type=Path)
    finalize.add_argument("--output-path", required=True, type=Path)
    finalize.add_argument("--latency-file", required=True, type=Path)
    finalize.add_argument("--manifest-file", required=True, type=Path)
    finalize.add_argument("--run-name", required=True)
    finalize.add_argument("--batch-id", default="")
    finalize.add_argument("--start-epoch", required=True, type=float)
    finalize.add_argument("--end-epoch", required=True, type=float)
    finalize.add_argument("--return-code", required=True, type=int)

    event = sub.add_parser("manifest-event")
    event.add_argument("--manifest-file", required=True, type=Path)
    event.add_argument("--state", required=True)
    event.add_argument("--scenario-file", required=True, type=Path)
    event.add_argument("--trial-index", required=True, type=int)
    event.add_argument("--output-path", required=True, type=Path)
    event.add_argument("--run-name", required=True)
    event.add_argument("--reason", default="")
    event.add_argument("--batch-id", default="")

    validate = sub.add_parser("validate-run-shell")
    validate.add_argument("--run-dir", required=True, type=Path)
    validate.add_argument("--scenario-glob", required=True)
    validate.add_argument("--trials", required=True, type=int)
    validate.add_argument("--run-name", default="")
    validate.add_argument("--require-latency", action="store_true")
    return parser


def main() -> None:
    args = _build_parser().parse_args()
    if args.command == "trial-status-shell":
        result = classify_trial(
            run_dir=args.run_dir,
            scenario_file=args.scenario_file,
            trial_index=args.trial_index,
            output_path=args.output_path,
            latency_file=args.latency_file,
            require_latency=args.require_latency,
        )
        _emit_shell(
            {
                "RESUME_STATE": result["state"],
                "RESUME_COMPLETE": _shell_bool(bool(result["complete"])),
                "RESUME_SUCCESS": _shell_bool(bool(result["success"])),
                "RESUME_OUTPUT_PATH": result["output_path"],
                "RESUME_REASON": result["reason"],
            }
        )
        return
    if args.command == "preserve-incomplete":
        preserved = preserve_incomplete_output(args.output_path)
        if preserved is not None:
            write_manifest_event(
                manifest_file=args.manifest_file,
                state="incomplete",
                scenario_file=args.scenario_file,
                trial_index=args.trial_index,
                output_path=preserved,
                run_name=args.run_name,
                reason=args.reason,
                batch_id=args.batch_id,
            )
        return
    if args.command == "finalize-trial-shell":
        result = finalize_trial(
            scenario_file=args.scenario_file,
            trial_index=args.trial_index,
            temp_output=args.temp_output,
            output_path=args.output_path,
            latency_file=args.latency_file,
            manifest_file=args.manifest_file,
            run_name=args.run_name,
            batch_id=args.batch_id,
            start_epoch=args.start_epoch,
            end_epoch=args.end_epoch,
            return_code=args.return_code,
        )
        _emit_shell(
            {
                "FINAL_STATE": result["state"],
                "FINAL_SUCCESS": _shell_bool(bool(result["success"])),
                "FINAL_REASON": result["reason"],
            }
        )
        return
    if args.command == "manifest-event":
        write_manifest_event(
            manifest_file=args.manifest_file,
            state=args.state,
            scenario_file=args.scenario_file,
            trial_index=args.trial_index,
            output_path=args.output_path,
            run_name=args.run_name,
            reason=args.reason,
            batch_id=args.batch_id,
        )
        return
    if args.command == "validate-run-shell":
        result = validate_run_artifacts(
            run_dir=args.run_dir,
            scenario_glob=args.scenario_glob,
            trials=args.trials,
            run_name=args.run_name,
            require_latency=args.require_latency,
        )
        missing_sample = result["missing"][:5]
        _emit_shell(
            {
                "VALIDATION_PASSED": _shell_bool(bool(result["valid"])),
                "VALIDATION_EXPECTED": result["expected"],
                "VALIDATION_COMPLETE": result["complete"],
                "VALIDATION_SUCCESS": result["success"],
                "VALIDATION_FAILURE": result["failure"],
                "VALIDATION_MISSING": len(result["missing"]),
                "VALIDATION_REASON": result["reason"],
                "VALIDATION_MISSING_SAMPLE": json.dumps(
                    missing_sample, sort_keys=True, separators=(",", ":")
                ),
            }
        )
        if not result["valid"]:
            raise SystemExit(1)
        return
    raise AssertionError(args.command)


if __name__ == "__main__":
    try:
        main()
    except Exception as exc:
        print(f"gcp_resume_state: ERROR: {exc}", file=sys.stderr)
        raise