"""CLI: bundle a gated GEC adapter into a self-describing serve package.

The serving API must not import ``gec.*`` (research/serving stay
decoupled). So this offline script freezes everything serving needs into a
``serve_manifest.json``: base model, the variant's ``use_retrieval`` flag, and
the DARAG prompt strings. The bundle also carries the adapter, its tokenizer,
and the enriched datastore, so a server only needs the bundle directory.

    python scribe/training/scripts/export_serve.py \
      --adapter-dir artifacts/gec_lora/qwen3/full/seed-13 \
      --datastore artifacts/retrieval/term_datastore.json \
      --output artifacts/gec_serve

Set ``LLM_PROVIDER=gec_local`` and ``GEC_BUNDLE_PATH=<output>`` to serve it.
"""

from __future__ import annotations

import argparse
import hashlib
import json
import shutil
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[3] / "scribe" / "training"))
sys.path.insert(0, str(Path(__file__).resolve().parents[3] / "scribe"))

from gec.cliutil import configure_stdout  # noqa: E402

configure_stdout()

from gec.config import FALLBACK_BASE_MODEL  # noqa: E402
from gec.gate import run_gate  # noqa: E402
from gec.prompts import IM_END, IM_START, SYSTEM_PROMPT  # noqa: E402


def _read_variant(adapter_dir: Path) -> dict:
    marker = adapter_dir / "darag_variant.json"
    if marker.exists():
        try:
            return json.loads(marker.read_text(encoding="utf-8"))
        except (json.JSONDecodeError, OSError):
            pass
    return {"variant": "full", "use_retrieval": True}


def main() -> None:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--adapter-dir", required=True, help="trained LoRA adapter directory")
    parser.add_argument("--datastore", required=True, help="enriched term datastore JSON")
    parser.add_argument("--output", default="artifacts/gec_serve", help="bundle output dir")
    parser.add_argument(
        "--base-model",
        default=None,
        help="optional expected model; actual export identity comes from the adapter revision lock",
    )
    parser.add_argument("--fallback-base-model", default=FALLBACK_BASE_MODEL)
    parser.add_argument("--max-new-tokens", type=int, default=256)
    parser.add_argument("--normal-gate-report", required=True)
    parser.add_argument("--frozen-gate-report", required=True)
    parser.add_argument("--frozen-safety-report", required=True)
    args = parser.parse_args()

    adapter_dir = Path(args.adapter_dir)
    if not adapter_dir.exists():
        raise SystemExit(f"Adapter dir not found: {adapter_dir}. Train + gate one first.")
    datastore = Path(args.datastore)
    if not datastore.exists():
        raise SystemExit(f"Datastore not found: {datastore}. Build it first.")
    if (adapter_dir / "adapter_config.json").exists() and json.loads(
        (adapter_dir / "adapter_config.json").read_text(encoding="utf-8")
    ).get("mock"):
        raise SystemExit("mock adapters can never produce an accepted serve bundle")
    revision_lock = json.loads(
        (adapter_dir / "base_revision.json").read_text(encoding="utf-8")
    )
    revision = str(revision_lock.get("revision", ""))
    actual_base_model = str(revision_lock.get("model", ""))
    if not actual_base_model or len(revision) != 40:
        raise SystemExit("adapter lacks an exact base/tokenizer revision lock")
    if args.base_model and actual_base_model != args.base_model:
        raise SystemExit("adapter base model differs from the explicit export expectation")
    normal_path = Path(args.normal_gate_report)
    frozen_path = Path(args.frozen_gate_report)
    safety_path = Path(args.frozen_safety_report)
    normal = json.loads(normal_path.read_text(encoding="utf-8"))
    frozen = json.loads(frozen_path.read_text(encoding="utf-8"))
    safety = json.loads(safety_path.read_text(encoding="utf-8"))
    normal_accepted, _ = run_gate(normal)
    frozen_accepted, _ = run_gate(
        frozen,
        candidate="gec_pred",
        baselines=("raw_asr",),
        splits=("frozen",),
        safety_report=safety,
        safety_split="frozen",
    )
    if not normal_accepted or not frozen_accepted:
        raise SystemExit("normal and frozen GEC gates must both be accepted before export")

    bundle = Path(args.output)
    bundle.mkdir(parents=True, exist_ok=True)
    # Copy the adapter (+ its tokenizer + darag_variant.json) and datastore in,
    # so the bundle is portable from Drive to a serving box on its own.
    adapter_out = bundle / "adapter"
    if adapter_out.exists():
        shutil.rmtree(adapter_out)
    shutil.copytree(adapter_dir, adapter_out)
    shutil.copy2(datastore, bundle / "term_datastore.json")

    variant = _read_variant(adapter_dir)
    manifest = {
        "schema": "carepath.gec.serve/1",
        "base_model": actual_base_model,
        "base_revision": revision,
        "tokenizer_revision": revision,
        "fallback_base_model": args.fallback_base_model,
        "variant": variant.get("variant", "full"),
        "use_retrieval": bool(variant.get("use_retrieval", True)),
        "max_new_tokens": args.max_new_tokens,
        "adapter_dir": "adapter",
        "datastore": "term_datastore.json",
        "gate_accepted": True,
        "gate_evidence": {
            "normal_report_sha256": hashlib.sha256(normal_path.read_bytes()).hexdigest(),
            "frozen_report_sha256": hashlib.sha256(frozen_path.read_bytes()).hexdigest(),
            "frozen_safety_report_sha256": hashlib.sha256(safety_path.read_bytes()).hexdigest(),
            "adapter_files": {
                str(path.relative_to(adapter_dir)): hashlib.sha256(path.read_bytes()).hexdigest()
                for path in sorted(adapter_dir.rglob("*"))
                if path.is_file()
            },
        },
        # Frozen DARAG prompt so serving reproduces the training format with no
        # dependency on gec.prompts.
        "prompt": {
            "system": SYSTEM_PROMPT,
            "im_start": IM_START,
            "im_end": IM_END,
            "best_label": "Best hypothesis: ",
            "others_label": "Other hypotheses:",
            "entities_label": "Named entities: ",
        },
    }
    (bundle / "serve_manifest.json").write_text(
        json.dumps(manifest, ensure_ascii=False, indent=2), encoding="utf-8"
    )
    print(f"Wrote serve bundle -> {bundle}")
    print(f"  variant={manifest['variant']} use_retrieval={manifest['use_retrieval']} "
          f"base={manifest['base_model']}")
    print(f"Serve with: LLM_PROVIDER=gec_local GEC_BUNDLE_PATH={bundle}")


if __name__ == "__main__":
    main()