"""Harness: dataset loading, evaluation loop, CLI."""

from __future__ import annotations

import argparse
import json
import sys
import traceback
from pathlib import Path
from typing import Any, Callable, Iterable, Sequence

from .cases_build import build, manifest, write_jsonl
from .grade import grade_case
from .prompts import render_case
from .report import build_report, render_markdown, write_report
from .runners import Prompt, Runner, build_runner, run_batch
from .schema import PROTOCOLS, Case, CaseResult, Protocol
from .tools import tools_for

ROOT = Path(__file__).resolve().parent.parent
DATASET_PATH = ROOT / "data" / "tooluse1.jsonl"
RESULTS_DIR = ROOT / "results"


def load_cases(
    path: Path = DATASET_PATH,
    langs: Sequence[str] | None = None,
    categories: Sequence[str] | None = None,
    limit: int | None = None,
) -> list[Case]:
    if not path.exists():
        raise FileNotFoundError(f"dataset not found at {path}; run `python -m tooluse1.harness build`")
    cases: list[Case] = []
    with path.open(encoding="utf-8") as handle:
        for line in handle:
            line = line.strip()
            if line:
                cases.append(Case.from_dict(json.loads(line)))
    if langs:
        wanted = {lang.lower() for lang in langs}
        cases = [case for case in cases if case.lang in wanted]
    if categories:
        wanted_categories = {category.lower() for category in categories}
        cases = [case for case in cases if case.category in wanted_categories]
    if limit is not None:
        cases = cases[:limit]
    return cases


def _failed_result(case: Case, protocol: Protocol, error: str) -> CaseResult:
    return CaseResult(
        case_id=case.id,
        protocol=protocol,
        lang=case.lang,
        category=case.category,
        difficulty=case.difficulty,
        passed=False,
        called=False,
        expected_call=case.expect.kind == "call",
        name_correct=False,
        args_exact=False,
        answer_ok=False,
        malformed=False,
        output="",
        detail=error or "runner error",
    )


def run_cases(
    cases: Sequence[Case],
    runner: Runner,
    protocols: Sequence[Protocol] = PROTOCOLS,
    on_result: Callable[[CaseResult], None] | None = None,
    skip: set[tuple[str, str]] | None = None,
    batch_size: int = 1,
) -> list[CaseResult]:
    results: list[CaseResult] = []
    done = skip or set()
    step = max(1, batch_size)
    for protocol in protocols:
        pending = [case for case in cases if (case.id, protocol) not in done]
        for start in range(0, len(pending), step):
            chunk = pending[start : start + step]
            prompts = [
                Prompt(
                    case=case,
                    protocol=protocol,
                    messages=tuple(render_case(case, protocol, tools_for(case.tools))),
                )
                for case in chunk
            ]
            outputs = run_batch(runner, prompts, step)
            for case, output in zip(chunk, outputs):
                result = (
                    _failed_result(case, protocol, output.error)
                    if output.text is None
                    else grade_case(case, protocol, output.text)
                )
                results.append(result)
                if on_result is not None:
                    on_result(result)
    return results


def slugify(model_id: str) -> str:
    return model_id.replace("/", "__").replace("\\", "__").replace(":", "-") or "model"


def _dedupe(results: Iterable[CaseResult]) -> list[CaseResult]:
    seen: dict[tuple[str, str], CaseResult] = {}
    for result in results:
        seen[(result.case_id, result.protocol)] = result
    return list(seen.values())


def _cmd_build(args: argparse.Namespace) -> int:
    cases = build()
    path = write_jsonl(cases, Path(args.out))
    info = manifest(cases, source=path)
    (path.parent / "manifest.json").write_text(json.dumps(info, ensure_ascii=False, indent=2), encoding="utf-8")
    print(json.dumps(info, ensure_ascii=False, indent=2))
    return 0


def _cmd_run(args: argparse.Namespace) -> int:
    protocols: tuple[Protocol, ...] = tuple(PROTOCOLS) if args.protocol == "all" else (args.protocol,)
    cases = load_cases(
        Path(args.dataset),
        langs=args.langs.split(",") if args.langs else None,
        categories=args.category.split(",") if args.category else None,
        limit=args.limit,
    )
    out_dir = Path(args.out)
    out_dir.mkdir(parents=True, exist_ok=True)
    stem = f"{slugify(args.name or args.model or args.backend)}__{args.protocol}"

    existing = _dedupe(_load_results(out_dir / f"{stem}.json")) if args.resume else []
    done = {(result.case_id, result.protocol) for result in existing}

    runner = build_runner(
        args.backend,
        model=args.model,
        base_url=args.base_url,
        api_key=args.api_key,
        max_new_tokens=args.max_new_tokens,
        scripted_file=args.scripted_file,
        dtype=args.dtype,
        disable_thinking=not args.thinking,
    )
    if args.model and args.backend in ("transformers", "local"):
        print(
            f"loaded via {getattr(runner, 'load_info', 'n/a')} | "
            f"thinking {'on' if args.thinking else 'off'} | max_new_tokens={args.max_new_tokens} | dtype={args.dtype}"
        )

    total = sum(1 for protocol in protocols for case in cases if (case.id, protocol) not in done)
    print(
        f"model={runner.name} backend={args.backend} protocol={args.protocol} "
        f"cases={len(cases)} evaluations={total} batch={args.batch_size}"
    )

    collected: list[CaseResult] = list(existing)
    progress = {"done": 0, "passed": 0}

    def snapshot(partial: bool) -> dict[str, Any]:
        results = _dedupe(collected)
        results.sort(key=lambda item: (item.protocol, item.case_id))
        report = build_report(results, model_id=args.name or (runner.name if args.model else args.backend), protocol=args.protocol)
        if args.notes:
            report["notes"] = args.notes
        report["partial"] = partial
        return report

    def on_result(result: CaseResult) -> None:
        collected.append(result)
        progress["done"] += 1
        if result.passed:
            progress["passed"] += 1
        if not result.passed and args.verbose:
            print(f"[{progress['done']}/{total}] FAIL {result.case_id} ({result.protocol}) {result.detail[:160]}")
        if progress["done"] % 25 == 0:
            write_report(snapshot(True), out_dir, stem)
            print(
                f"[{progress['done']}/{total}] {progress['passed'] / progress['done'] * 100:.1f}%"
                f" (checkpoint written, --resume safe)"
            )

    run_cases(cases, runner=runner, protocols=protocols, on_result=on_result, skip=done, batch_size=args.batch_size)

    report = snapshot(False)
    paths = write_report(report, out_dir, stem)
    print(render_markdown(report["summary"]))
    print(f"wrote {paths['json']} and {paths['markdown']}")
    return 0


def _load_results(path: Path) -> list[CaseResult]:
    if not path.exists():
        return []
    payload = json.loads(path.read_text(encoding="utf-8"))
    return [
        CaseResult(
            case_id=item["case_id"],
            protocol=item["protocol"],
            lang=item["lang"],
            category=item["category"],
            difficulty=item["difficulty"],
            passed=item["passed"],
            called=item["called"],
            expected_call=item["expected_call"],
            name_correct=item["name_correct"],
            args_exact=item["args_exact"],
            answer_ok=item["answer_ok"],
            malformed=item["malformed"],
            output=item["output"],
            detail=item.get("detail", ""),
        )
        for item in payload.get("results", [])
    ]


def _cmd_selftest(args: argparse.Namespace) -> int:
    """Validate the grader against runners with known, exact behaviour."""
    cases = load_cases(Path(args.dataset), limit=args.limit)
    expectations = {"oracle": 1.0, "fenced": 1.0, "thinking": 1.0}
    failures: list[str] = []

    for backend in ("oracle", "fenced", "thinking", "null"):
        runner = build_runner(backend)
        results = run_cases(cases, runner, protocols=tuple(PROTOCOLS))
        report = build_report(results, model_id=backend, protocol="all")
        overall = report["summary"]["overall"]
        print(
            f"{backend:<9} n={overall['cases']:<4} score={overall['score'] * 100:6.1f}%  "
            f"calls={overall['correct_call_when_expected'] * 100:6.1f}%  "
            f"abstain={overall['correct_abstention'] * 100:6.1f}%  "
            f"spurious={overall['spurious_call_rate'] * 100:6.1f}%"
        )
        if backend in expectations and overall["score"] < expectations[backend]:
            failures.append(f"{backend} scored {overall['score']} < {expectations[backend]}")
            for item in report["failures"][:10]:
                failures.append(f"  {backend}: {item['case_id']} ({item['protocol']}) {item['detail'][:140]}")
        if backend == "null" and overall["correct_call_when_expected"] > 0:
            failures.append("null runner produced calls")
    if args.out:
        runner = build_runner("oracle")
        report = build_report(run_cases(cases, runner, protocols=tuple(PROTOCOLS)), model_id="oracle", protocol="all")
        write_report(report, Path(args.out), "selftest__oracle__all")
    if failures:
        print("\nSELFTEST FAILURES")
        print("\n".join(failures))
        return 1
    print("\nselftest passed: grading is consistent with the corpus across all protocols")
    return 0


def _cmd_report(args: argparse.Namespace) -> int:
    results = _load_results(Path(args.results))
    report = build_report(results, model_id=args.model, protocol=args.protocol)
    markdown = render_markdown(report["summary"], report)
    if args.out:
        Path(args.out).write_text(markdown, encoding="utf-8")
        print(f"wrote {args.out}")
    else:
        print(markdown)
    return 0


def build_parser() -> argparse.ArgumentParser:
    parser = argparse.ArgumentParser(prog="tooluse1", description="ToolUse.1 tool-calling benchmark")
    subparsers = parser.add_subparsers(dest="command", required=True)

    build_parser_ = subparsers.add_parser("build", help="regenerate the frozen dataset")
    build_parser_.add_argument("--out", default=str(DATASET_PATH))
    build_parser_.set_defaults(func=_cmd_build)

    run_parser = subparsers.add_parser("run", help="evaluate a model")
    run_parser.add_argument("--model", default="", help="model id or local path")
    run_parser.add_argument("--backend", default="transformers", choices=["transformers", "local", "openai", "vllm", "ollama", "llamacpp", "scripted", "oracle", "null", "fenced", "thinking"])
    run_parser.add_argument("--base-url", default="http://localhost:8000/v1")
    run_parser.add_argument("--api-key", default="")
    run_parser.add_argument("--scripted-file", default="")
    run_parser.add_argument("--protocol", default="all", choices=["all", *PROTOCOLS])
    run_parser.add_argument("--langs", default="")
    run_parser.add_argument("--category", default="")
    run_parser.add_argument("--limit", type=int, default=None)
    run_parser.add_argument("--max-new-tokens", type=int, default=256)
    run_parser.add_argument(
        "--dtype",
        default="auto",
        choices=["auto", "bfloat16", "float16", "float32"],
        help="compute dtype; T4/Turing has no bfloat16, use float16 there (and report it)",
    )
    run_parser.add_argument("--dataset", default=str(DATASET_PATH))
    run_parser.add_argument(
        "--batch-size",
        type=int,
        default=1,
        help="evaluations per generate call (local backends; 8-16 saturates a small GPU)",
    )
    run_parser.add_argument("--out", default=str(RESULTS_DIR))
    run_parser.add_argument("--name", default="", help="human-readable run label; overrides the model path in the results file and filename")
    run_parser.add_argument("--notes", default="")
    run_parser.add_argument("--resume", action="store_true")
    run_parser.add_argument("--thinking", action="store_true", help="do not disable the model's reasoning mode")
    run_parser.add_argument("--verbose", "-v", action="store_true")
    run_parser.set_defaults(func=_cmd_run)

    selftest = subparsers.add_parser("selftest", help="check the grader against known-good runners")
    selftest.add_argument("--dataset", default=str(DATASET_PATH))
    selftest.add_argument("--limit", type=int, default=None)
    selftest.add_argument("--out", default="")
    selftest.set_defaults(func=_cmd_selftest)

    report_parser = subparsers.add_parser("report", help="re-render a results file as markdown")
    report_parser.add_argument("results")
    report_parser.add_argument("--model", default="")
    report_parser.add_argument("--protocol", default="all")
    report_parser.add_argument("--out", default="")
    report_parser.set_defaults(func=_cmd_report)
    return parser


def main(argv: Sequence[str] | None = None) -> int:
    parser = build_parser()
    args = parser.parse_args(argv)
    try:
        return int(args.func(args))
    except FileNotFoundError as error:
        print(f"error: {error}", file=sys.stderr)
        return 2
    except KeyboardInterrupt:
        print("\ninterrupted", file=sys.stderr)
        return 130
    except Exception:  # noqa: BLE001
        traceback.print_exc()
        return 1


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