class _LevelSplitItemSchema(BaseModel):
    level: Literal["project", "signal"]
    content: str = Field(min_length=1, max_length=4000)


class _LevelClassificationSchema(BaseModel):
    build_intent_score: float = Field(ge=0.0, le=1.0)
    scope_score: float = Field(ge=0.0, le=1.0)
    timeline_score: float = Field(ge=0.0, le=1.0)
    owner_score: float = Field(ge=0.0, le=1.0)
    project_score: float = Field(ge=0.0, le=1.0)
    level: Literal["project", "signal"]
    level_confidence: float = Field(ge=0.0, le=1.0)
    level_reasoning: str = Field(min_length=1, max_length=600)
    should_split: bool = False
    split_items: list[_LevelSplitItemSchema] = Field(default_factory=list, max_length=2)


class _SignalExtractionSchema(BaseModel):
    title: str = Field(min_length=1, max_length=200)
    type: Literal["竞品动态", "用户反馈", "项目风险", "新需求"]
    priority: Literal["P0", "P1", "P2", "P3"]
    matched_project_id: Optional[int] = None
    summary: str = Field(min_length=1, max_length=3000)
    reasoning: list[str] = Field(min_length=1, max_length=3)
    confidence: float = Field(ge=0.0, le=1.0)
    recommended_action: Literal["enter_only", "create_charter", "trigger_alert"]


class _ProjectPrefillSchema(BaseModel):
    suggested_name: str = Field(min_length=1, max_length=255)
    suggested_description: str = Field(min_length=1, max_length=4000)
    suggested_owner: str = Field(min_length=1, max_length=120)
    suggested_timeline: str = Field(min_length=1, max_length=120)
    confidence: float = Field(ge=0.0, le=1.0)
    reasoning: list[str] = Field(min_length=1, max_length=3)


def _normalize_reasoning(value: Any, max_items: int = 3) -> list[str]:
    if isinstance(value, list):
        rows = [str(x).strip() for x in value if str(x).strip()]
        return rows[:max_items]
    if isinstance(value, str):
        parts = [p.strip(" -•\t") for p in value.splitlines() if p.strip()]
        return parts[:max_items]
    return []


def _safe_json_object(value: str) -> dict[str, Any]:
    raw = (value or "").strip()
    if raw.startswith("```"):
        chunks = raw.split("```")
        if len(chunks) >= 2:
            raw = chunks[1].strip()
        if raw.startswith("json"):
            raw = raw[4:].strip()
    try:
        parsed = json.loads(raw)
        return parsed if isinstance(parsed, dict) else {}
    except Exception:
        return {}


def _validate_schema(
    schema: type[BaseModel],
    payload: dict[str, Any],
    *,
    context: str,
) -> dict[str, Any]:
    if not isinstance(payload, dict):
        raise ValueError(f"{context}_schema_invalid: payload_not_object")
    try:
        if hasattr(schema, "model_validate"):
            model = schema.model_validate(payload)  # type: ignore[attr-defined]
        else:
            model = schema.parse_obj(payload)  # type: ignore[attr-defined]
    except ValidationError as exc:
        raise ValueError(f"{context}_schema_invalid: {str(exc)[:400]}") from exc
    if hasattr(model, "model_dump"):
        return model.model_dump()  # type: ignore[no-any-return]
    return model.dict()  # type: ignore[no-any-return]


def _safe_float(value: Any, default: float = 0.0) -> float:
    try:
        return float(value)
    except (TypeError, ValueError):
        return float(default)


def _safe_bool(value: Any, default: bool = False) -> bool:
    if isinstance(value, bool):
        return value
    if value is None:
        return default
    text = str(value).strip().lower()
    if text in {"1", "true", "yes", "y", "on", "是", "真"}:
        return True
    if text in {"0", "false", "no", "n", "off", "否", "假"}:
        return False
    return default


def _safe_int(value: Any) -> Optional[int]:
    if isinstance(value, bool):
        return None
    try:
        return int(str(value).strip())
    except (TypeError, ValueError):
        return None


def _normalize_level_value(value: Any, default: str = "signal") -> str:
    text = str(value or "").strip().lower()
    if not text:
        return default
    if text in {"project", "project-level", "project_level", "new_project"}:
        return "project"
    if text in {"signal", "signal-level", "signal_level"}:
        return "signal"
    if text in {"项目", "项目级", "立项", "新项目"}:
        return "project"
    if text in {"信号", "信号级", "需求", "需求级", "事件"}:
        return "signal"
    if "project" in text or "项目" in text or "立项" in text:
        return "project"
    if "signal" in text or "信号" in text or "需求" in text:
        return "signal"
    return default


def _first_non_empty(data: dict[str, Any], keys: tuple[str, ...]) -> Any:
    for key in keys:
        if key not in data:
            continue
        value = data.get(key)
        if value is None:
            continue
        if isinstance(value, str) and not value.strip():
            continue
        return value
    return None


def _utc_now() -> datetime:
    return now_cn_aware()


def _compact_text(value: Any, max_len: int = 160) -> str:
    text = str(value or "").strip()
    if len(text) <= max_len:
        return text
    return f"{text[: max_len - 3]}..."


def _safe_dict(value: Any) -> dict[str, Any]:
    if isinstance(value, dict):
        return value
    if isinstance(value, str):
        return _safe_json_object(value)
    return {}


def _build_undo_deadline(value: Optional[datetime], *, minutes: int = 10) -> Optional[datetime]:
    if value is None:
        return None
    if value.tzinfo is not None:
        value = value.astimezone(CN_TZ).replace(tzinfo=None)
    return value + timedelta(minutes=minutes)