"""Phase B Verifier MVP — tool 인자 결정적 검증.

룰: R1(tag-existence), R2(area-format), R4(trace_connections 보강).
응답 텍스트 검증(R3, R5)은 Phase B.2 — stub만.
"""
from __future__ import annotations
import json, re, time, pathlib
from typing import Optional, Any

TAG_RE  = re.compile(r'^[a-z][a-z0-9]*-\d+[a-z]?(\.[a-z0-9]+)?$')
AREA_RE = re.compile(r'^[A-Z][A-Z0-9]+(-\d+)?$')
VALID_AREAS = {"P1","P2","P3","P4","P5","P6","P8","P9","P10","UTIL","PACKING"}
VALID_DIRECTIONS = {"upstream","downstream"}

_LOG_DIR = pathlib.Path(__file__).parent / "logs"

class VerifierError(Exception):
    def __init__(self, rule: str, code: str, hint: str, **extra):
        self.rule, self.code, self.hint, self.extra = rule, code, hint, extra
    def to_dict(self) -> dict:
        return {"verifier_error": f"{self.rule}.{self.code}", "hint": self.hint, **self.extra}

# ── 태그 캐시 ──
_tag_cache: set[str] | None = None
_tag_cache_at: float = 0.0
_TAG_CACHE_TTL: float = 300.0  # 5분

def _load_tag_set(get_conn) -> set[str]:
    global _tag_cache, _tag_cache_at
    if _tag_cache is not None and (time.time() - _tag_cache_at) < _TAG_CACHE_TTL:
        return _tag_cache
    conn = get_conn()
    try:
        with conn.cursor() as cur:
            cur.execute("SELECT DISTINCT base_tag FROM tag_metadata WHERE base_tag IS NOT NULL")
            s = {r[0].lower() for r in cur.fetchall() if r[0]}
            cur.execute("SELECT DISTINCT tag_no FROM pid_equipment WHERE tag_no IS NOT NULL")
            s |= {r[0].lower() for r in cur.fetchall() if r[0]}
    finally:
        conn.close()
    _tag_cache, _tag_cache_at = s, time.time()
    return s

# ── R1 ──
def validate_tag(tag: str | None, get_conn) -> Optional[VerifierError]:
    if not tag:
        return None
    t = tag.lower()
    if not TAG_RE.match(t):
        return VerifierError("R1","invalid_tag_format",
            hint=f"태그 형식 비정상: '{tag}'. 예시: ficq-6113.pv, p-6102")
    base = t.split('.')[0]
    tags = _load_tag_set(get_conn)
    if base in tags:
        return None
    toks = [p for p in base.split('-') if len(p) > 2]
    suggested = sorted({x for x in tags if any(p in x for p in toks)})[:3]
    return VerifierError("R1","tag_not_found",
        hint=f"태그 '{tag}' 는 DB에 존재하지 않습니다. find_tags(query=..., sub_area=...) 로 먼저 검색하세요.",
        suggested=suggested)

# ── R2 ──
def validate_area(area: str | None, field: str = "area") -> Optional[VerifierError]:
    if not area:
        return None
    area = area.upper()
    if not AREA_RE.match(area):
        return VerifierError("R2","invalid_area_format",
            hint=f"{field}='{area}' 형식 오류. 'P6' 또는 'P6-1' 형식 사용.",
            valid_areas=sorted(VALID_AREAS))
    base = area.split('-')[0]
    if base not in VALID_AREAS:
        return VerifierError("R2","unknown_area",
            hint=f"{field}='{area}' 미존재. valid: {sorted(VALID_AREAS)} (P7 없음)")
    return None

# ── R4 ──
def validate_direction(d: str | None) -> Optional[VerifierError]:
    if d and d not in VALID_DIRECTIONS:
        return VerifierError("R4","invalid_direction",
            hint=f"direction='{d}' 잘못. 'upstream' 또는 'downstream' 만 허용")
    return None

def validate_max_depth(n: Any) -> Optional[VerifierError]:
    if n is None: return None
    try:
        v = int(n)
    except Exception:
        return VerifierError("R4","invalid_max_depth", hint=f"max_depth='{n}' 은 정수여야 함")
    if not (1 <= v <= 50):
        return VerifierError("R4","max_depth_out_of_range", hint=f"max_depth={v} 범위 외 (1~50)")
    return None

# ── R3, R5 stub (Phase B.2) ──
def validate_response_text(text: str) -> Optional[VerifierError]:
    return None  # Phase B.2 구현 예정

# ── 로그 적재 (Phase C LoRA 입력) ──
def log_rejection(tool: str, params: dict, err: VerifierError) -> None:
    _LOG_DIR.mkdir(parents=True, exist_ok=True)
    today = time.strftime("%Y-%m-%d")
    rec = {"ts": time.time(), "tool": tool, "params": params,
           "verifier_error": err.to_dict()}
    with (_LOG_DIR / f"{today}.jsonl").open("a", encoding="utf-8") as f:
        f.write(json.dumps(rec, ensure_ascii=False) + "\n")