"""Knowledge-pipeline eval runner.

Scores an already-parsed document against `knowledge_gold.yaml` and writes a
timestamped result file. The 2026-08-24 figures were assembled by hand; this is
the reproducible version, so a number can be re-derived instead of trusted.

**Takes a ParsedDocument artifact, never a PDF.** MinerU is not invoked and is
not required — that is the seam doing its job. Point it at the `chunks.json`
written by `python -m src.knowledge_parsing.run`.

    # free: E1 recall, E2 compression, the funnel. No API calls, no spend.
    ./.venv/Scripts/python.exe -m eval.knowledge.run_eval <artifact.json>

    # add the paid branches: E3 schema fill and rule recall
    ./.venv/Scripts/python.exe -m eval.knowledge.run_eval <artifact.json> --extract

    # exercise every branch with no spend and no credentials (NOT scoreable)
    ./.venv/Scripts/python.exe -m eval.knowledge.run_eval <artifact.json> --extract --mock

Module mode only (`-m`). A file-path invocation breaks `sys.path` and the
`src.` imports below fail.

    # a BAND instead of a number — repeats the paid stage only. SPENDS N TIMES.
    ./.venv/Scripts/python.exe -m eval.knowledge.run_eval <artifact.json> --extract --runs 5

Exit codes: `0` clean · `1` below a kill line · `2` bad arguments or artifact ·
`3` no extractor · `4` would overwrite a result · `5` an invariant broke ·
`6` a different model snapshot served the run.

Four things this refuses to do, all for the same reason — a number that cannot
be compared is worse than no number:

* **It will not run on an artifact that does not declare `parser_backend`.**
  The same MinerU build emits different text from `pipeline` and `hybrid/high`,
  so results measured on different backends are not comparable and nothing
  downstream can tell them apart afterwards. `--allow-unlabelled-artifact`
  overrides, and stamps the result file so the caveat travels with it.
* **It never overwrites a result file.** Every run writes a new timestamped
  file beside the others; the frozen baseline stays frozen.
* **It refuses a run served by a different model snapshot** than the committed
  results were measured on (`EXPECTED_MODEL_SNAPSHOT`). X25 recorded what served
  a run; this asserts it, so a silent tier move stops the comparison instead of
  quietly poisoning the delta column.
* **It refuses a run that broke a structural invariant** (`invariants.py`) —
  a span that is not locatable, a duplicate entity id, a repaired rejection.
  Those are defects rather than scores, so they fail the run outright.
"""

from __future__ import annotations

import argparse
import json
import statistics
import sys
from collections import Counter
from datetime import datetime
from pathlib import Path
from typing import Any

from src.knowledge_extraction.adapter import parsed_doc_from_artifact
from src.knowledge_extraction.extract import MockExtractor, cacheable, prefix_tokens
from src.knowledge_extraction.genre import classify as classify_genre
from src.knowledge_extraction.service import (
    build_clusters,
    estimate_cost,
    extract_all,
    run_filters,
)
from src.knowledge_extraction.settings import EVIDENCE_K

from .invariants import check_invariants
from .score import (
    GOLD_PATH,
    load_gold,
    score_glossary,
    score_post_cluster,
    score_rules,
    score_term_filter,
)

_HERE = Path(__file__).resolve().parent
RESULTS_DIR = _HERE / "results"

# The kill lines. Each is a decision already taken, recorded in
# KNOWLEDGE_PIPELINE_CALIBRATION.md — not a target invented per run.
# E2's kill line was REMOVED 2026-09-10. Compression is now reported as a
# descriptive statistic only, never as pass/fail.
#
# The reason is not that 2.0 was the wrong number — it is that the metric moves
# the WRONG WAY. Over-merging distinct terms into one cluster RAISES compression,
# so the defect that cost the gold term EWH its own entry was pushing this score
# up and through its own pass line. A metric whose pass condition is partly met
# by the defect it should expose is worse than no metric. Retiring the fuzzy pass
# correctly LOWERED compression (BUMA 2.712 -> 2.183), which under a kill line
# would have read as a regression.
#
# E1c (post-cluster recall) is the metric that actually watches this stage.
KILL_LINES = {"E1": 0.70, "E3": 0.80}

# What the last committed run measured, for the delta column. Rule recall has
# no kill line: it is tracked, not gated, and 3/15 is the post-X22 scoring of
# the 2026-08-24 run — NOT the 1/15 in that file, which predates the scorer fix.
# Re-baselined to MISTRAL 2026-09-02 (M1). The delta column compares like with
# like or it lies: `mistral` is now the default backend (knowledge_parsing/
# config.py), so leaving MinerU's numbers here would have printed every future
# run against a parse it cannot be compared to — the same cross-backend
# comparison this harness refuses elsewhere by rejecting unlabelled artifacts.
#
# Previous MinerU baseline, kept for the record, NOT for comparison:
#   v2_full_document_2026-08-24_093051.json — E1 0.8049 · E2 2.81 · E3 0.90 · rule 0.2
BASELINE = {
    "file": "v2_full_2026-09-02_160326.json",
    "E1": 0.8780,
    "E2": 2.6970,
    "E3": 1.0000,
    "rule_recall": 0.5,
}

# ── Step 0: measurement hardening ───────────────────────────────────────
# The snapshot every committed result on this branch was measured against. X25
# started RECORDING what served a run; this makes it an ASSERTION, which is the
# difference between a fact discoverable by diffing two files afterwards and one
# that stops a run at the moment it stops being true.
#
# A deployment name is OUR label and never changes; the snapshot behind it can
# move without notice. When it does, every number in `results/` becomes a
# measurement of a different system and the delta column starts lying. Comparing
# against a moved model is the failure this catches — not the move itself, which
# is Azure's business.
#
# `--expect-model` overrides for a deliberate tier change; `--allow-model-drift`
# downgrades the refusal to a stamped warning when you need the number anyway.
EXPECTED_MODEL_SNAPSHOT = "gpt-5.4-nano-2026-03-17"

# Below this spread, two runs of one document are telling the same story. Above
# it, a single run is not evidence and the band must be quoted instead of the
# point. 0.10 is the handoff's own read of this corpus (identical input scored
# 6/7 one day and 0/12 the next), not a measured tolerance — raise or lower it
# once `--runs` has produced a real band on a real document.
NOISE_BAND = 0.10


def _azure_extractor():
    """Built lazily: importing it requires credentials to be configured."""
    from src.knowledge_extraction.extract import AzureExtractor

    try:
        return AzureExtractor()
    except Exception as exc:  # noqa: BLE001 - reported, not raised
        print(f"cannot build the Azure extractor: {exc!r}", file=sys.stderr)
        return None


def _latex_verification_counts(formulas: list[dict]) -> dict[str, int]:
    """How many stored formulas carry which guarantee.

    Cheap and free — the marker is set during validation, not by a model call —
    and it is the fastest read on whether an artifact's markup is rich enough
    to support the guard at all. A run that is all `unverified_operator` was
    parsed with a backend that cannot express multiplication.
    """
    counts = Counter(f.get("latex_verification") or "none" for f in formulas)
    return dict(sorted(counts.items()))


def _verdict(value: float, kill: float | None) -> str:
    if kill is None:
        return "—"
    return "PASS" if value >= kill else "FAIL"


def _delta(value: float, previous: float | None) -> str:
    if previous is None:
        return "—"
    diff = round(value - previous, 4)
    return f"{diff:+.4f}"


def _stability(values: list[float]) -> dict[str, Any]:
    """A band, not a number.

    The reported value becomes the MEDIAN rather than the mean: one run that
    fails schema validation drags a mean into a region no run actually
    occupied, and a metric nobody measured is worse than a noisy one.
    """
    ordered = sorted(values)
    return {
        "n": len(ordered),
        "min": round(ordered[0], 4),
        "median": round(statistics.median(ordered), 4),
        "max": round(ordered[-1], 4),
        "spread": round(ordered[-1] - ordered[0], 4),
        "runs": [round(v, 4) for v in values],
        "noisy": bool(ordered[-1] - ordered[0] > NOISE_BAND),
    }


def _entity_ids(result) -> dict[str, list[str]]:
    """Every id a run minted, by kind — the thing an expert's approval hangs on.

    K11 fixed two ids that did not survive a re-run. Nothing has watched them
    since, and a re-run that re-keys its entries silently orphans every approval
    recorded against the old ones. Cheap to check, catastrophic to miss.
    """
    return {
        "glossary": sorted(e.get("term_id") or "" for e in result.glossary),
        "rule": sorted(e.get("rule_id") or "" for e in result.rules),
        "formula": sorted(e.get("formula_id") or "" for e in result.formulas),
    }


def _id_stability(per_run: list[dict[str, list[str]]]) -> dict[str, Any]:
    """Did every run mint the same ids? Anything but `True` is a defect."""
    if len(per_run) < 2:
        return {"comparable": False, "note": "needs --runs 2 or more"}
    first = per_run[0]
    drift = {
        kind: {
            "only_in_first": sorted(set(first[kind]) - set(other[kind]))[:10],
            "only_in_later": sorted(set(other[kind]) - set(first[kind]))[:10],
        }
        for other in per_run[1:]
        for kind in first
        if set(first[kind]) != set(other[kind])
    }
    return {"comparable": True, "identical_across_runs": not drift, "drift": drift}


def _served_snapshots(result) -> list[str]:
    return sorted({u.model_version for u in result.usages if u.model_version})


def build_report(
    doc,
    filtered,
    clustered,
    scores: dict[str, Any],
    result,
    args,
    started: datetime,
    seconds: float,
    invariants=None,
    stability: dict[str, Any] | None = None,
) -> dict:
    funnel = {
        "pages": doc.n_pages,
        "chunks": len(doc.chunks),
        "mentions_raw": len(filtered.mentions),
        "clusters": clustered.n_clusters,
        "compression_ratio": clustered.compression_ratio,
        "abbrev_pairs": len(filtered.abbrev_pairs),
        "rule_candidates": len(filtered.rule_candidates),
    }
    report: dict[str, Any] = {
        "run": {
            "created_at": started.strftime("%Y-%m-%d_%H%M%S"),
            "doc_id": doc.doc_id,
            "artifact": str(args.artifact),
            "content_hash": doc.content_hash,
            "parser": f"{doc.parser_name}/{doc.parser_version}",
            "parser_backend": doc.parser_backend or "UNLABELLED",
            "extracted": bool(args.extract),
            "mock": bool(args.mock),
            "limit": args.limit,
            "runs": args.runs,
            "expected_model": args.expect_model,
            "seconds": round(seconds, 1),
        },
        "funnel": funnel,
        "genre": classify_genre(doc, filtered).as_dict(),
        "scores": scores,
        "baseline": BASELINE,
    }
    if invariants is not None:
        report["invariants"] = invariants.as_dict()
    if stability:
        report["stability"] = stability

    if args.allow_unlabelled_artifact and not doc.parser_backend:
        report["run"]["comparability"] = (
            "NOT COMPARABLE — the artifact does not declare parser_backend and the "
            "run was forced. Different MinerU backends emit different text."
        )
    if args.mock:
        report["run"]["comparability"] = (
            "NOT SCOREABLE — mock extractor. Branch plumbing only; the content is "
            "fabricated, so every quality figure here is meaningless."
        )

    if result is not None:
        # Which model actually served this run. A result file without it is a
        # measurement of an unknown: on 2026-08-27 identical input scored 6/7
        # one day and 0/12 the next under an unchanged deployment name, and
        # nothing recorded said whether the model had moved. See X25.
        served = _served_snapshots(result)
        report["run"]["served_by"] = {
            "model_version": served,
            "system_fingerprint": sorted(
                {u.system_fingerprint for u in result.usages if u.system_fingerprint}
            ),
        }
        # Step 0(a): the recorded snapshot becomes an assertion. A mock run
        # reports no snapshot and is exempt — it measures plumbing, not a model.
        if not args.mock and served and served != [args.expect_model]:
            report["run"]["model_drift"] = {
                "expected": args.expect_model,
                "served": served,
                "forced": bool(args.allow_model_drift),
                "note": (
                    "every committed result was measured on the expected snapshot; "
                    "a delta against this run compares two different systems"
                ),
            }
        prompt, cached, completion = result.total_tokens
        report["cost"] = {
            "prompt_tokens": prompt,
            "cached_tokens": cached,
            "completion_tokens": completion,
            "cache_hit_rate": round(cached / prompt, 3) if prompt else 0.0,
            "calls": len(result.usages),
        }
        report["quality"] = {
            "fields_rejected_by_span_check": len(result.rejected),
            "rejections": [r.model_dump(mode="json") for r in result.rejected[:20]],
            "glossary_entries": len(result.glossary),
            "rule_entries": len(result.rules),
            "formula_entries": len(result.formulas),
            "abstained_null_definition": sum(
                1 for e in result.glossary if not e.get("definition")
            ),
            "latex_verification": _latex_verification_counts(result.formulas),
            "links": result.links,
        }
    return report


def format_summary(report: dict) -> str:
    rows = []
    for key, score in report["scores"].items():
        value = score["value"]
        kill = KILL_LINES.get(key)
        band = score.get("stability")
        suffix = ""
        if band:
            suffix = (
                f"  [{band['min']:.4f}..{band['max']:.4f}] n={band['n']}"
                + ("  NOISY" if band["noisy"] else "")
            )
        rows.append(
            f"  {key:<12} {value:>8.4f}   kill {kill if kill else '  —  '!s:>5}   "
            f"{_verdict(value, kill):<5}  vs baseline {_delta(value, BASELINE.get(key))}"
            f"   {score['label']}{suffix}"
        )
    funnel = report["funnel"]
    out = [
        "",
        f"  doc {report['run']['doc_id']}   backend {report['run']['parser_backend']}"
        f"   {funnel['pages']} pages -> {funnel['chunks']} chunks -> "
        f"{funnel['mentions_raw']} mentions -> {funnel['clusters']} clusters "
        f"({funnel['compression_ratio']}x)",
        "",
        *rows,
    ]
    if "cost" in report:
        cost = report["cost"]
        out += [
            "",
            f"  {cost['calls']} calls   {cost['prompt_tokens']} prompt tokens, "
            f"{cost['cached_tokens']} cached ({cost['cache_hit_rate']:.0%})",
            f"  {report['quality']['fields_rejected_by_span_check']} fields rejected"
            " by the span check",
            f"  latex_verification: {report['quality']['latex_verification']}",
        ]
    genre = report.get("genre")
    if genre:
        out += [
            "",
            f"  genre: {genre['genre']}  (labels {genre['labels_variant']}, "
            f"well-served {genre['well_served']})   {genre['signals']}",
        ]
        for reason in genre["reasons"]:
            out += [f"    · {reason}"]
        for warning in genre["warnings"]:
            out += [f"    !! {warning}"]
    if "invariants" in report:
        inv = report["invariants"]
        out += [
            "",
            f"  invariants: {'OK' if inv['ok'] else str(inv['n_violations']) + ' VIOLATED'}"
            f"   checked {inv['checked']}",
        ]
        for violation in inv["violations"][:10]:
            out += [f"    !! {violation['check']} [{violation['kind']}] {violation['detail']}"]
    if "stability" in report:
        ids = report["stability"]["entity_ids"]
        if ids.get("comparable"):
            out += [
                f"  entity ids identical across runs: {ids['identical_across_runs']}"
            ]
    if "model_drift" in report["run"]:
        drift = report["run"]["model_drift"]
        out += [
            "",
            f"  !! MODEL DRIFT — expected {drift['expected']}, served "
            f"{', '.join(drift['served'])}",
        ]
    if "comparability" in report["run"]:
        out += ["", f"  !! {report['run']['comparability']}"]
    return "\n".join(out)


def main(argv: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(
        description="Score the knowledge pipeline against knowledge_gold.yaml"
    )
    parser.add_argument("artifact", type=Path, help="ParsedDocument JSON (chunks.json)")
    parser.add_argument("--doc-id", help="override the artifact's doc_id")
    parser.add_argument(
        "--extract", action="store_true", help="run the PAID branches (E3, rule recall)"
    )
    parser.add_argument(
        "--mock", action="store_true", help="mock extractor: no network, no spend, NOT scoreable"
    )
    parser.add_argument("--limit", type=int, help="cap items per branch (pilot)")
    parser.add_argument("--active-glossary", type=Path, help="glossary to diff against")
    parser.add_argument("--gold", type=Path, default=GOLD_PATH)
    parser.add_argument("--label", help="short note recorded in the result file")
    parser.add_argument(
        "--dry-run", action="store_true", help="token estimate only, zero API calls"
    )
    parser.add_argument(
        "--allow-unlabelled-artifact",
        action="store_true",
        help="run on an artifact with no parser_backend (results NOT comparable)",
    )
    parser.add_argument(
        "--runs",
        type=int,
        default=1,
        metavar="N",
        help=(
            "repeat the PAID stage N times and report min/median/max instead of a "
            "single number. MULTIPLIES SPEND BY N — the free stages run once"
        ),
    )
    parser.add_argument(
        "--expect-model",
        default=EXPECTED_MODEL_SNAPSHOT,
        help=f"model snapshot this run must be served by (default {EXPECTED_MODEL_SNAPSHOT})",
    )
    parser.add_argument(
        "--allow-model-drift",
        action="store_true",
        help="record a snapshot mismatch as a warning instead of refusing the run",
    )
    args = parser.parse_args(argv)

    if args.runs < 1:
        print("--runs must be 1 or more", file=sys.stderr)
        return 2
    if args.runs > 1 and not args.extract:
        print(
            "--runs only varies the PAID stage; the free stages are deterministic.\n"
            "  Add --extract, or drop --runs.",
            file=sys.stderr,
        )
        return 2

    if not args.artifact.exists():
        print(f"artifact not found: {args.artifact}", file=sys.stderr)
        return 2

    raw = json.loads(args.artifact.read_text(encoding="utf-8"))
    doc = parsed_doc_from_artifact(raw, doc_id=args.doc_id, source_ref=str(args.artifact))

    if not doc.parser_backend and not args.allow_unlabelled_artifact:
        print(
            f"artifact does not declare parser_backend: {args.artifact}\n"
            "  A score measured on one MinerU backend is not comparable to one\n"
            "  measured on another, and nothing downstream can tell them apart\n"
            "  afterwards. Re-export from `src.knowledge_parsing.run`, or pass\n"
            "  --allow-unlabelled-artifact to record the result as uncomparable.",
            file=sys.stderr,
        )
        return 2

    started = datetime.now()
    gold = load_gold(args.gold)

    filtered = run_filters(doc)
    clustered = build_clusters(doc, filtered)

    if args.dry_run:
        est = estimate_cost(doc, clustered, filtered, args.limit)
        print("[dry-run] NO API CALLS MADE")
        for key, value in est.items():
            print(f"          {key}: {value}")
        for branch in ("glossary", "rule", "formula", "summary"):
            print(
                f"          prefix[{branch}]: {prefix_tokens(branch)} tokens, "
                f"cacheable={cacheable(branch)}"
            )
        return 0

    e1 = score_term_filter(gold, [m.surface for m in filtered.mentions])
    canonicals = [c.canonical for c in clustered.clusters]
    e1c_loose = score_post_cluster(gold, canonicals)
    e1c_strict = score_post_cluster(gold, canonicals, cluster_variants=True)
    scores: dict[str, Any] = {
        "E1": {
            "label": "term-filter recall",
            "value": e1.recall,
            "detail": e1.as_dict(),
        },
        # E1c watches the merge stage, which E1 (measured before clustering) and
        # E3 (measured only over entries that produced a definition) both miss.
        # `E1 - E1c_loose` is the recall clustering destroyed; 0 is the target.
        "E1c_loose": {
            "label": "post-cluster recall (loose)",
            "value": e1c_loose.recall,
            "detail": e1c_loose.as_dict(),
        },
        "E1c_strict": {
            "label": "post-cluster recall (owns its own cluster)",
            "value": e1c_strict.recall,
            "detail": e1c_strict.as_dict(),
        },
        "E2": {
            "label": "review-burden compression (descriptive, NOT gated)",
            "value": clustered.compression_ratio,
            "detail": {
                "mentions": clustered.n_mentions,
                "clusters": clustered.n_clusters,
            },
        },
    }

    result = None
    invariants = None
    stability: dict[str, Any] = {}
    if args.extract:
        extractor = MockExtractor() if args.mock else _azure_extractor()
        if extractor is None:
            return 3
        active = (
            json.loads(args.active_glossary.read_text(encoding="utf-8"))
            if args.active_glossary
            else None
        )

        # The free stages are deterministic and already done — only the paid
        # stage is repeated. Re-running GLiNER N times would cost minutes to
        # re-derive an identical clustering.
        e3_values: list[float] = []
        rule_values: list[float] = []
        ids_per_run: list[dict[str, list[str]]] = []
        violations_per_run: list[int] = []

        for run_index in range(args.runs):
            if args.runs > 1:
                print(f"  run {run_index + 1}/{args.runs} ...", file=sys.stderr)
            result = extract_all(doc, clustered, filtered, extractor, args.limit, active)
            e3 = score_glossary(gold, result.glossary)
            rules = score_rules(gold, result.rules)
            e3_values.append(e3.precision)
            rule_values.append(rules.recall)
            ids_per_run.append(_entity_ids(result))
            invariants = check_invariants(result, doc)
            violations_per_run.append(len(invariants.violations))

        # The LAST run's detail is reported beside the band. Detail from one run
        # of several is an example, not a summary — labelled as such below.
        scores["E3"] = {
            "label": "glossary schema fill (precision)",
            "value": round(statistics.median(e3_values), 4),
            "detail": e3.as_dict(),
        }
        scores["rule_recall"] = {
            "label": "rule-branch recall",
            "value": round(statistics.median(rule_values), 4),
            "detail": rules.as_dict(),
        }
        if args.runs > 1:
            scores["E3"]["stability"] = _stability(e3_values)
            scores["rule_recall"]["stability"] = _stability(rule_values)
            for key in ("E3", "rule_recall"):
                scores[key]["detail"]["note"] = (
                    f"detail is from run {args.runs} of {args.runs}; the value is "
                    "the median across runs"
                )
        stability = {
            "runs": args.runs,
            "entity_ids": _id_stability(ids_per_run),
            "violations_per_run": violations_per_run,
        }

    seconds = (datetime.now() - started).total_seconds()
    report = build_report(
        doc, filtered, clustered, scores, result, args, started, seconds,
        invariants=invariants, stability=stability,
    )
    if args.label:
        report["run"]["label"] = args.label
    if not args.extract:
        report["run"]["note"] = (
            "Free stages only. E3 and rule recall require --extract, which spends."
        )

    print(format_summary(report))

    RESULTS_DIR.mkdir(parents=True, exist_ok=True)
    stem = "mock" if args.mock else ("full" if args.extract else "filters")
    out_path = RESULTS_DIR / f"v2_{stem}_{started:%Y-%m-%d_%H%M%S}.json"
    if out_path.exists():  # never overwrite a committed measurement
        print(f"refusing to overwrite {out_path}", file=sys.stderr)
        return 4
    out_path.write_text(
        json.dumps(report, ensure_ascii=False, indent=2), encoding="utf-8"
    )
    print(f"\n-> saved: {out_path.relative_to(_HERE.parent.parent)}")

    # Invariants first, and regardless of the tier: a broken structural claim
    # means a control leaked, which invalidates the scores rather than joining
    # them. Mock runs included — the plumbing is exactly what they test.
    if invariants is not None and not invariants.ok:
        print(
            f"\nINVARIANTS VIOLATED: {len(invariants.violations)} — see the result file",
            file=sys.stderr,
        )
        return 5

    if "model_drift" in report["run"] and not args.allow_model_drift:
        print(
            "\nMODEL SNAPSHOT MISMATCH — the run is recorded but must not be compared\n"
            "  to the committed results. Re-pin with --expect-model, or pass\n"
            "  --allow-model-drift to accept the caveat.",
            file=sys.stderr,
        )
        return 6

    if EVIDENCE_K and args.extract and not args.mock:
        failed = [
            k for k, s in scores.items() if k in KILL_LINES and s["value"] < KILL_LINES[k]
        ]
        if failed:
            print(f"\nBELOW KILL LINE: {', '.join(failed)}", file=sys.stderr)
            return 1
    return 0


if __name__ == "__main__":
    raise SystemExit(main())