"""Summary-gate configuration and the fail policy.

Pure module: no FastAPI imports and no HTTPException.

Non-DB config is module-level load_dotenv() + os.getenv (house style). Model /
token / effort / cache knobs come from the bulk-ats Settings, same as
inbox_classifier.plugins.get_triage_settings.
"""

from __future__ import annotations

import os

from dotenv import load_dotenv
from summary_gate.prompt import PROMPT_VERSION

from app.core.config import Settings, get_settings

load_dotenv()


def _flag(name, default) -> bool:
    raw=(os.getenv(name) or "").strip().lower()
    if not raw:
        return default
    return raw in ("1","true","yes","on")


# false restores pre-gate behaviour: every pair with a CV is ATS-scored.
GATE_ENABLED=_flag("SUMMARY_GATE_ENABLED",True)

# true: a provider outage or a missing key lets the pair through to ATS.
# Fail-closed would silently skip scoring when OPENAI_API_KEY is unset.
GATE_FAIL_OPEN=_flag("SUMMARY_GATE_FAIL_OPEN",True)

GATE_MAX_SUMMARY_CHARS=max(int(os.getenv("SUMMARY_GATE_MAX_SUMMARY_CHARS") or 500),1)
# Same bound as the inbox intake body cap — enough for title + requirements.
GATE_MAX_JD_CHARS=max(int(os.getenv("SUMMARY_GATE_MAX_JD_CHARS") or 4000),1)
# 0 disables the uncertainty branch (0.0 < 0.0 is False).
GATE_MIN_CONFIDENCE=float(os.getenv("SUMMARY_GATE_MIN_CONFIDENCE") or 0)

PROMPT_CACHE_KEY=f"summary-gate-{PROMPT_VERSION}"

UNCLASSIFIED_PREFIX="unclassified:"

CLASSIFIED="classified"
LOW_CONFIDENCE="low_confidence"
ERROR="error"

# Backend-local skip code. Not an app.core.errors.ErrorCode — the bulk-ats
# engine never sees this pair; the CV is never opened.
SUMMARY_NOT_SUITABLE="SUMMARY_NOT_SUITABLE"


def get_gate_settings() -> Settings:
    return get_settings()


def clip_text(value, limit) -> str:
    text=str(value or "")
    if len(text)<=limit:
        return text
    return text[:limit]


def should_score(verdict, error_code="") -> tuple[bool,str,str]:
    """(proceed, status, reason) — the entire fail policy, in one place.

    No verdict means the model could not be consulted. SUMMARY_GATE_FAIL_OPEN
    decides. A present verdict uses is_suitable, unless confidence is below
    SUMMARY_GATE_MIN_CONFIDENCE (the gradient threshold).
    """
    if verdict is None:
        reason=f"{UNCLASSIFIED_PREFIX}{error_code or 'unknown'}"[:60]
        return GATE_FAIL_OPEN,ERROR,reason
    if verdict.confidence<GATE_MIN_CONFIDENCE:
        return GATE_FAIL_OPEN,LOW_CONFIDENCE,SUMMARY_NOT_SUITABLE
    if verdict.is_suitable:
        return True,CLASSIFIED,"suitable"
    return False,CLASSIFIED,SUMMARY_NOT_SUITABLE