"""오버나이트 hier 분해 + 절 분석 backfill (ADDITIVE — 검색 코퍼스 미교체).

Engineering + Industrial_Safety 미분해 기술문서를 deadline(기본 07:00 KST) 전까지:
  doc → persist_hier_tree(build + leaf embed, in_corpus=false) → 절 분석(Mac mini gemma-26B) → commit
검색 코퍼스(replace_doc_corpus) 미터치 → eval baseline/reindex 무관, 무위험.
시간 초과 시 leaf 경계에서 안전 중단(멱등 — 다음 실행이 미처리분만 이어서).

절 분석 상수/헬퍼는 section_summary_pilot 에서 import = PROMPT_VERSION 단일 진실(멱등 보존).
no silent fallback(call_triage 직접) / Semaphore(1) BACKGROUND gate / 새 Semaphore 금지.

실행 (GPU 서버, background):
  docker compose exec -T fastapi python /app/scripts/hier_overnight_backfill.py run --deadline 07:00
  docker compose exec -T fastapi python /app/scripts/hier_overnight_backfill.py dry-run
"""

import argparse
import asyncio
import os
import statistics
import sys
import time
from collections import Counter
from datetime import datetime, timedelta

sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))

from sqlalchemy import text
from sqlalchemy.ext.asyncio import async_sessionmaker, create_async_engine

from ai.client import AIClient, parse_json_response, strip_thinking
from core.config import settings
from services.hier_decomp.persist import persist_hier_tree
from services.search.llm_gate import Priority, acquire_mlx_gate

# 단일 진실: 절 분석 상수/헬퍼 (PROMPT_VERSION 일치 = 멱등 보존)
from section_summary_pilot import (
    CALL_TIMEOUT_S, MIN_CHARS, PROMPT_VERSION, _UPSERT_SQL, _build_prompt, _coerce_type,
)

EXCLUDE_DOMAINS = ["news"]  # 기본 = 뉴스만 제외, 나머지 전부 (allowlist 는 --domains 로 override)
DOC_MIN_CHARS = 4000   # hier 분해가 의미 있는 doc 크기 하한(STRUCTURE_SPLIT_THRESHOLD=4000)
BUFFER_MIN = 10        # deadline 이 만큼 전 안전 중단


def _candidate_sql(allowlist, doc_ids=None):
    """allowlist 있으면 그 domain 만, 없으면 EXCLUDE_DOMAINS(news) 제외 전부.
    doc_ids 명시 시 = 그 doc 만(크기 게이트 DOC_MIN_CHARS + domain 필터 우회 —
    구조화 소형 문서(법령 등) eval coverage 보정용. NOT EXISTS hier 멱등 가드는 유지).
    작은 doc 먼저 = 완료 doc 수 최대화 + 단일 mega-doc 예산 독식 방지."""
    if doc_ids:
        cond, gate = "d.id = ANY(:doc_ids)", ""  # 명시 doc = 크기 게이트 우회
    else:
        cond = ("lower(split_part(coalesce(d.ai_domain,''), '/', 1)) = ANY(:domains)"
                if allowlist else
                "lower(split_part(coalesce(d.ai_domain,''), '/', 1)) <> ALL(:exclude)")
        gate = "AND length(d.extracted_text) > :minchars"
    return text(f"""
        SELECT d.id AS doc_id, d.extracted_text AS body, d.ai_domain AS ai_domain
        FROM documents d
        WHERE d.extracted_text IS NOT NULL
          {gate}
          AND {cond}
          AND NOT EXISTS (SELECT 1 FROM document_chunks dc
                          WHERE dc.doc_id = d.id AND dc.source_type = 'hier_section')
        ORDER BY length(d.extracted_text) ASC
    """)


def _candidate_params(allowlist, doc_ids=None):
    if doc_ids:
        return {"doc_ids": doc_ids}
    p = {"minchars": DOC_MIN_CHARS}
    if allowlist:
        p["domains"] = allowlist
    else:
        p["exclude"] = EXCLUDE_DOMAINS
    return p


def _scope_label(allowlist, doc_ids=None):
    if doc_ids:
        return f"doc-list={len(doc_ids)}건(크기게이트 우회)"
    return f"allowlist={allowlist}" if allowlist else f"all-except={EXCLUDE_DOMAINS}"

# 멱등 leaf 선별 (재실행 시 이미 분석된 leaf 제외)
LEAF_SQL = text("""
    SELECT dc.id AS chunk_id, dc.heading_path, dc.section_title,
           dc.text AS body, length(dc.text) AS body_len,
           dc.chunk_content_hash AS content_hash
    FROM document_chunks dc
    WHERE dc.doc_id = :doc AND dc.source_type = 'hier_section' AND dc.is_leaf = true
      AND NOT EXISTS (SELECT 1 FROM chunk_section_analysis a
                      WHERE a.chunk_id = dc.id AND a.prompt_version = :pv
                        AND a.source_content_hash = dc.chunk_content_hash)
    ORDER BY dc.chunk_index
""")


def _now():
    return datetime.now()


def _log(msg):
    print(f"[{_now():%H:%M:%S}] {msg}", flush=True)


def _compute_deadline(hhmm: str) -> datetime:
    h, m = (int(x) for x in hhmm.split(":"))
    now = _now()
    target = now.replace(hour=h, minute=m, second=0, microsecond=0)
    if target <= now:
        target += timedelta(days=1)
    return target


def _make_engine():
    return create_async_engine(os.environ["DATABASE_URL"], pool_pre_ping=True)


async def _analyze_doc_leaves(session, client, doc_id, doc_domain, model_name, stop_at):
    """doc 의 미분석 hier leaf 분석 → upsert. stop_at(epoch) 넘으면 leaf 경계 중단."""
    rows = (await session.execute(LEAF_SQL, {"doc": doc_id, "pv": PROMPT_VERSION})).mappings().all()
    ok = fail = skip = 0
    timings, types = [], []
    aborted = False
    for r in rows:
        if time.time() >= stop_at:
            aborted = True
            break
        if r["body_len"] < MIN_CHARS:
            await session.execute(_UPSERT_SQL, {
                "chunk_id": r["chunk_id"], "status": "skipped_tiny", "summary": None,
                "section_type": None, "domain": doc_domain, "confidence": None,
                "model": None, "pv": PROMPT_VERSION, "content_hash": r["content_hash"], "error": None,
            })
            skip += 1
            continue
        status, summary, sec_type, conf, err = "failed", None, None, None, None
        start = time.perf_counter()
        try:
            async with acquire_mlx_gate(Priority.BACKGROUND):
                async with asyncio.timeout(CALL_TIMEOUT_S):
                    raw = await client.call_triage(_build_prompt(r))
            timings.append(time.perf_counter() - start)
            parsed = parse_json_response(strip_thinking(raw)) if raw else None
            if parsed and isinstance(parsed, dict):
                summary = (parsed.get("summary") or "").strip() or None
                sec_type = _coerce_type(parsed.get("section_type"))
                try:
                    conf = float(parsed.get("confidence"))
                except (TypeError, ValueError):
                    conf = 0.5
                status, ok = "summarized", ok + 1
                types.append(sec_type)
            else:
                err, fail = "parse_failed", fail + 1
        except Exception as exc:  # timeout/호출 실패 — no fallback
            timings.append(time.perf_counter() - start)
            err, fail = f"{type(exc).__name__}: {repr(exc)[:160]}", fail + 1
        await session.execute(_UPSERT_SQL, {
            "chunk_id": r["chunk_id"], "status": status, "summary": summary,
            "section_type": sec_type, "domain": doc_domain, "confidence": conf,
            "model": model_name, "pv": PROMPT_VERSION,
            "content_hash": r["content_hash"], "error": err,
        })
        await session.commit()
    await session.commit()
    return {"ok": ok, "fail": fail, "skip": skip, "leaves": len(rows),
            "timings": timings, "types": types, "aborted": aborted}


def _parse_doc_ids(args):
    raw = getattr(args, "doc", None)
    return [int(x) for x in raw.split(",") if x.strip()] if raw else None


async def cmd_dry_run(args):
    allowlist = args.domains.split(",") if args.domains else None
    doc_ids = _parse_doc_ids(args)
    engine = _make_engine()
    sm = async_sessionmaker(engine, expire_on_commit=False)
    async with sm() as session:
        rows = (await session.execute(_candidate_sql(allowlist, doc_ids),
                _candidate_params(allowlist, doc_ids))).mappings().all()
    await engine.dispose()
    gate_lbl = "doc-list" if doc_ids else f">{DOC_MIN_CHARS}자"
    print(f"[dry-run] 후보 doc {len(rows)} ({_scope_label(allowlist, doc_ids)}, {gate_lbl}, 미분해)")
    if rows:
        lens = [len(r["body"]) for r in rows]
        print(f"  본문길이: min={min(lens)} p50={int(statistics.median(lens))} max={max(lens)} 합={sum(lens):,}")
        print("  앞 5개:")
        for r in rows[:5]:
            print(f"    doc={r['doc_id']} {len(r['body']):>7,}자 {r['ai_domain']}")


async def cmd_run(args):
    allowlist = args.domains.split(",") if args.domains else None
    doc_ids = _parse_doc_ids(args)
    skip_analysis = getattr(args, "skip_analysis", False)
    deadline = _compute_deadline(args.deadline)
    stop_at = (deadline - timedelta(minutes=BUFFER_MIN)).timestamp()
    _log(f"deadline={deadline:%m-%d %H:%M} (buffer {BUFFER_MIN}m → stop_at={datetime.fromtimestamp(stop_at):%H:%M}) "
         f"{_scope_label(allowlist, doc_ids)}{' [SKIP-ANALYSIS: 분해+임베딩만]' if skip_analysis else ''}")

    engine = _make_engine()
    sm = async_sessionmaker(engine, expire_on_commit=False)
    client = AIClient()
    model_name = settings.ai.triage.model

    async def embed_leaf(t):
        try:
            return await client.embed(t)
        except Exception as exc:
            _log(f"  embed 실패(무시, in_corpus=false): {type(exc).__name__}")
            return None

    tot_docs = tot_ok = tot_fail = tot_skip = tot_leaves_created = 0
    all_timings, all_types = [], []
    run_start = time.time()
    try:
        async with sm() as session:
            cands = (await session.execute(_candidate_sql(allowlist, doc_ids),
                     _candidate_params(allowlist, doc_ids))).mappings().all()
        _log(f"후보 doc {len(cands)} 선별. 시작.")

        for c in cands:
            if time.time() >= stop_at:
                _log(f"⏰ deadline 버퍼 도달 — doc 경계에서 중단 (처리 {tot_docs} doc)")
                break
            doc_id, body, doc_domain = c["doc_id"], c["body"], c["ai_domain"]
            try:
                async with sm() as session:
                    pstat = await persist_hier_tree(session, doc_id, body, embed_leaf)
                leaves_created = pstat.get("leaves", 0)
                tot_leaves_created += leaves_created
                if skip_analysis:
                    # 분해+임베딩만 (절 분석 = Mac mini 별 축, retrieval 무관). 멱등.
                    astat = {"ok": 0, "fail": 0, "skip": 0, "leaves": leaves_created,
                             "timings": [], "types": [], "aborted": False}
                else:
                    async with sm() as session:
                        astat = await _analyze_doc_leaves(session, client, doc_id, doc_domain, model_name, stop_at)
            except Exception as exc:
                _log(f"  ✗ doc={doc_id} 처리 실패(건너뜀): {type(exc).__name__}: {repr(exc)[:160]}")
                continue

            tot_docs += 1
            tot_ok += astat["ok"]; tot_fail += astat["fail"]; tot_skip += astat["skip"]
            all_timings += astat["timings"]; all_types += astat["types"]
            avg = statistics.mean(astat["timings"]) if astat["timings"] else 0
            _log(f"  ✓ doc={doc_id} ({len(body):,}자 {doc_domain.split('/')[0]}) "
                 f"leaf생성={leaves_created} 분석ok={astat['ok']} fail={astat['fail']} skip={astat['skip']} "
                 f"avg={avg:.1f}s{' [ABORT]' if astat['aborted'] else ''} | 누적 {tot_docs}doc {tot_ok}leaf")
            if astat["aborted"]:
                _log("⏰ leaf 분석 중 deadline 도달 — 중단")
                break
    finally:
        await client.close()
        await engine.dispose()

    elapsed = (time.time() - run_start) / 60
    _log(f"=== 종료: {tot_docs} doc, leaf생성 {tot_leaves_created}, "
         f"분석 ok={tot_ok} fail={tot_fail} skip={tot_skip}, 경과 {elapsed:.0f}분 ===")
    if all_timings:
        _log(f"  leaf당 {statistics.mean(all_timings):.2f}s (p50={statistics.median(all_timings):.2f} "
             f"max={max(all_timings):.2f})")
    if all_types:
        d = Counter(all_types)
        _log(f"  section_type: {dict(d.most_common())}  other={d.get('other',0)/len(all_types):.1%}")


def main():
    ap = argparse.ArgumentParser(description="오버나이트 hier 분해+절 분석 backfill (additive)")
    sub = ap.add_subparsers(dest="cmd", required=True)
    p_dry = sub.add_parser("dry-run", help="후보 doc 집계 (작업 0)")
    p_dry.add_argument("--domains", default=None, help="comma-sep allowlist (미지정=뉴스 제외 전부)")
    p_dry.add_argument("--doc", default=None, help="comma-sep doc id (크기 게이트 우회 — 구조화 소형 문서 coverage 보정)")
    p_run = sub.add_parser("run", help="분해+분석 실행 (deadline time-box)")
    p_run.add_argument("--deadline", default="07:00", help="HH:MM (기본 07:00 — 컨테이너 UTC 주의, 07:00 KST=22:00 UTC)")
    p_run.add_argument("--domains", default=None, help="comma-sep allowlist (미지정=뉴스 제외 전부)")
    p_run.add_argument("--doc", default=None, help="comma-sep doc id (크기 게이트 우회 — 구조화 소형 문서 coverage 보정)")
    p_run.add_argument("--skip-analysis", action="store_true", help="절 분석(Mac mini) 생략, 분해+임베딩만 (retrieval go/no-go 측정 준비용)")
    args = ap.parse_args()
    fn = {"dry-run": cmd_dry_run, "run": cmd_run}[args.cmd]
    asyncio.run(fn(args))


if __name__ == "__main__":
    main()