"""T07-a 预审结果约束：把核查结果收敛成受约束的建议。

依据：docs/v2/01-requirements.md §5、03-detailed-design.md §5；
BR-05/06/07/12、E-02/06/07/08、AC-05/06/07/09/12/45。

本模块只做**确定性结论校验**，不调用任何模型、不算概率。四条不可让渡的规则：

1. **硬性阻断不可被覆盖**（BR-06）：已确认的 hard 规则命中即 `stop`，模型的高分
   或"建议推进"都不能翻盘。同时**保留模型原始结构化提案**供审计，并指出规则版本。
2. **未知不等于风险，也不等于通过**（BR-07）：关键核查不可完成时给
   `insufficient_information` 并列补件，**不得**据此评判企业高风险。
3. **单题不能代表综合意见**（BR-05）：专项判断只进 findings 与被引用，不能直接
   写入 recommendation。
4. **未校准就没有概率**（BR-12）：`probability` 恒为 None + `not_calibrated`，
   任何模型自报置信度都不改写它。
"""

from __future__ import annotations

RECOMMENDATIONS = ("advance", "supplement", "stop", "insufficient_information")

NOT_CALIBRATED = "not_calibrated"
NO_PROBABILITY_REASON = "尚未完成真实历史校准；不展示审批通过概率"

# 判定优先级（从上到下，先命中先返回）。顺序本身是业务口径，改动等于改结论。
PRECEDENCE = ("hard_block", "critical_incomplete", "open_findings", "clean")

INCOMPLETE_RESULTS = ("unknown", "error", "not_applicable")


def _codes(findings) -> set[str]:
    return {str(item.get("code")) for item in findings or () if item.get("code")}


def hard_blocks(findings, hard_rule_codes) -> list[dict]:
    """命中的硬性阻断项。`hard_rule_codes` 来自冻结方案里 effect=hard 且 on_match=block 的规则。"""
    wanted = set(hard_rule_codes or ())
    return [dict(item) for item in findings or () if item.get("code") in wanted]


def critical_incomplete(findings, critical_check_ids) -> list[str]:
    """关键核查项中未完成的那些编码（未知/执行失败/不适用）。"""
    critical = set(critical_check_ids or ())
    return sorted({
        str(item.get("code")) for item in findings or ()
        if item.get("code") in critical and item.get("result") in INCOMPLETE_RESULTS
    })


def open_findings(findings) -> list[dict]:
    """需要业务处理但未阻断的问题（issue / unknown）。"""
    return [dict(item) for item in findings or ()
            if item.get("result") in ("issue", "unknown")]


def probability() -> dict:
    """P0 恒为空。**不接受任何入参**——不给"顺手传个模型分数"留口子。"""
    return {"value": None, "reason": NOT_CALIBRATED, "message": NO_PROBABILITY_REASON}


def decide(findings, missing_inputs=(), degradations=(), judgments=(),
           critical_check_ids=(), hard_rule_codes=(), rule_versions=()) -> dict:
    """收敛结论。返回 recommendation 与支撑它的理由、降级与审计信息。"""
    blocks = hard_blocks(findings, hard_rule_codes)
    incomplete = critical_incomplete(findings, critical_check_ids)
    open_items = open_findings(findings)

    degradations = [dict(item) for item in degradations or ()]
    missing = sorted({str(item) for item in missing_inputs or ()})

    if blocks:
        # 命中硬阻断：即便专项模型给出正面单题判断，也不改变结论（BR-05 / BR-06）
        stage = "hard_block"
        recommendation = "stop"
        reason = "存在已确认的硬性阻断，暂不建议推进；" + "、".join(
            f'{item.get("code")}@{item.get("basis_version", "未标注版本")}' for item in blocks)
    elif incomplete:
        stage = "critical_incomplete"
        recommendation = "insufficient_information"
        reason = ("关键核查未能完成，无法形成结论，请补充材料后重新发起；"
                  "不得据此判定企业高风险。未完成项：" + "、".join(incomplete))
        missing = sorted(set(missing) | set(incomplete))
    elif open_items:
        stage = "open_findings"
        recommendation = "supplement"
        reason = f"存在 {len(open_items)} 项待处理事项，建议补充材料或说明后重新核查"
    else:
        stage = "clean"
        recommendation = "advance"
        reason = "已完成方案内的确定性核查，未发现阻断项；正式审批仍由业务流程决定"

    return {
        "recommendation": recommendation,
        "recommendation_reason": reason,
        "stage": stage,
        "findings": [dict(item) for item in findings or ()],
        "open_findings": open_items,
        "hard_blocks": blocks,
        "critical_incomplete": incomplete,
        "missing_inputs": missing,
        "degradations": degradations,
        # 专项判断只作为依据入档，**不参与** recommendation 的判定
        "judgments": [dict(item) for item in judgments or ()],
        "judgment_can_override": False,
        "rule_versions": [dict(item) for item in rule_versions or ()],
        "probability": probability(),
        # AC-45：stop 只是"暂不建议推进"，系统不得自动关闭项目或执行正式审批
        "formal_approval_touched": False,
    }


def assert_no_probability_leak(result: dict) -> None:
    """任何路径都不得产出未校准概率（BR-12 / AC-12）。"""
    value = (result.get("probability") or {}).get("value")
    if value is not None:
        raise ValueError("未校准的数据集不得产出审批通过概率")
    for item in result.get("judgments", ()):
        for metric in item.get("native_metrics", ()) or ():
            if str(metric.get("name", "")).lower() in ("probability", "approval_probability"):
                raise ValueError("专项模型的原生指标不得被当作审批概率")


def budget_exhausted(reason: str = "RUN_BUDGET_EXCEEDED") -> dict:
    """预算耗尽（E-08）：停止并列出未完成项，不伪造完成。"""
    return {"code": reason, "message": "本次核查已达到执行上限，请复核未完成项",
            "retryable": False}