#!/usr/bin/env python3
"""Backfill practice_area for external precedents (#153, step 4 — ingest contract).

87% of external court rulings (209/239) lack practice_area, so area-scoped retrieval
misses them. The classifier infrastructure already exists
(precedent_metadata_extractor.extract_and_apply → practice_area + metadata); it just
never ran on these rows. This runs it on the unclassified, throttled by usage_limits.

Deterministic shortcut first (derive_domain_practice_area from our case-number scheme,
free); only rows it can't resolve go to the LLM classifier.

  cd ~/legal-ai/mcp-server
  HOME=/home/chaim .venv/bin/python ../scripts/backfill_practice_area.py --dry-run
  HOME=/home/chaim .venv/bin/python ../scripts/backfill_practice_area.py --apply
"""
from __future__ import annotations

import argparse
import asyncio
import os
import sys

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "mcp-server", "src"))

from legal_mcp.services import db, precedent_metadata_extractor  # noqa: E402
from legal_mcp.services.practice_area import derive_domain_practice_area  # noqa: E402

try:
    from legal_mcp.services import usage_limits
except Exception:  # pragma: no cover
    usage_limits = None


def _over_ceiling() -> tuple[bool, str]:
    if usage_limits is None:
        return False, ""
    u = usage_limits.subscription_usage()
    if u is None:
        return False, ""
    over, _r, detail = usage_limits.ceiling_status(u)
    return over, detail


async def _run(apply: bool, limit: int | None, throttle: bool) -> int:
    pool = await db.get_pool()
    rows = await pool.fetch(
        "SELECT id, case_number FROM case_law "
        "WHERE source_kind='external_upload' AND COALESCE(practice_area,'')='' "
        "  AND COALESCE(full_text,'')<>'' ORDER BY created_at")
    if limit:
        rows = rows[:limit]
    print(f"[{'APPLY' if apply else 'DRY-RUN'}] {len(rows)} unclassified external precedents\n", flush=True)
    det = llm = stopped = 0
    by_area: dict[str, int] = {}
    for n, r in enumerate(rows, 1):
        # 1) deterministic from our case-number scheme (free)
        area = derive_domain_practice_area(r["case_number"] or "")
        if area:
            det += 1
            by_area[area] = by_area.get(area, 0) + 1
            if apply:
                await pool.execute("UPDATE case_law SET practice_area=$2 WHERE id=$1", r["id"], area)
            continue
        # 2) LLM classifier (throttled)
        if throttle:
            over, detail = _over_ceiling()
            if over:
                print(f"\n⏸ usage ceiling ({detail}) — stopping at {n-1}. Re-run to resume.", flush=True)
                stopped = 1
                break
        if apply:
            res = await precedent_metadata_extractor.extract_and_apply(r["id"])
            pa = (res or {}).get("practice_area") or ""
            if pa:
                llm += 1
                by_area[pa] = by_area.get(pa, 0) + 1
        else:
            llm += 1
        if n % 20 == 0:
            print(f"  …{n}/{len(rows)}", flush=True)
    print(f"\n── summary ── deterministic: {det} · LLM: {llm} · by_area: {by_area}"
          f"{' (stopped early)' if stopped else ''}")
    if not apply:
        print("dry-run — nothing written. Re-run with --apply.")
    return 0


def main() -> int:
    p = argparse.ArgumentParser(description="Backfill practice_area for external precedents (#153)")
    p.add_argument("--apply", action="store_true")
    p.add_argument("--limit", type=int, default=None)
    p.add_argument("--no-throttle", action="store_true")
    a = p.parse_args()
    return asyncio.run(_run(a.apply, a.limit, not a.no_throttle))


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