"""Reader-only applicability notes; never changes dasha calculations or periods."""

BOUNDARY = "第二时间轴，仅供交叉核对，不单独生成应期"
MISSING = "缺少本次计算的结构化适用性证据，无法确认各辅助时间轴是否适用；不补算、不补写日期。"


REASON_LABELS = {
    "patyayini_dasha_missing": "本次计算未提供帕特雅伊尼年运周期，暂不能用于时间核对。",
    "The Shodashottari hora-plus-paksha applicability gate is not met.": "未满足该大运对时辰分区与月相组合的适用条件。",
    "This profile requires Navamsa Lagna in Taurus or Libra.": "该大运要求九分盘上升落在金牛座或天秤座，本次未满足。",
    "Dwisaptatisama requires Lagna lord in the 1st or 7th house.": "该大运要求上升主星位于第一宫或第七宫，本次未满足。",
    "Panchottari requires a Cancer Ascendant that is also Cancer in Dwadasamsa.": "该大运要求本命及十二分盘上升均为巨蟹座，本次未满足。",
    "Satabdika requires a vargottama Ascendant (same Rasi and Navamsa sign).": "该大运要求本命及九分盘上升同星座，本次未满足。",
    "Chaturshitisama requires the 10th lord to occupy the 10th house.": "该大运要求第十宫主星位于第十宫，本次未满足。",
    "Shastihayani requires Sun in the Lagna sign.": "该大运要求太阳位于上升星座，本次未满足。",
}


def _reader_reason(value):
    if value in REASON_LABELS:
        return REASON_LABELS[value]
    if value.startswith("Moon Nakshatra '") and "does not qualify for Ashtottari Dasha under " in value:
        return "月宿与月相组合未满足该大运的适用条件，不绕过判定。"
    return "计算返回了限制原因，但暂无可核对的详细说明；不据此补写适用条件或日期。"


def _has_periods(key, raw, source):
    fields = ("periods", "major") + (("mahadasha_sequence", "dense_boundaries") if key == "narayana" else ())
    return any(isinstance(data.get(field), (list, dict)) and bool(data[field]) for data in (raw, source) for field in fields)


def _cell(value):
    return str(value).replace("|", "／").replace("\r", " ").replace("\n", " ").replace("<", "＜").replace(">", "＞")


def render_dasha_applicability(packet):
    timing = packet.get("worksheets", {}).get("timing_and_predictive_systems", {})
    master = timing.get("dasha_master_pack", {})
    families = master.get("families", {})
    lines = ["", "## 辅助时间轴适用性（参数敏感）", ""]
    if not isinstance(families, dict) or not families:
        return "\n".join(lines + [MISSING, ""])
    families = dict(families)
    annual = timing.get("annual_tajika_pack", {})
    for key, value in annual.items():
        if key.endswith("_dasha"):
            families.setdefault(key.removesuffix("_dasha"), value)
    lines += ["| 大运族 | 是否适用 / 原因 | 使用边界 |", "| --- | --- | --- |"]
    for key in sorted(families):
        if key == "vimshottari":
            continue
        raw = families[key] if isinstance(families[key], dict) else {}
        source_key = "kalachakra_dasha" if key == "kala_chakra" else f"{key}_dasha"
        source = timing.get(source_key, {})
        source = source if isinstance(source, dict) else {}
        status = raw.get("status", raw.get("execution_status"))
        applicable = source.get("applicable", raw.get("applicable"))
        if applicable is False or status == "not_applicable":
            reason = "本次不适用，不绕过原适用条件，不补写日期。"
        elif status in {"blocked", "missing_in_local", "unavailable"}:
            reason = "本次不可用：本地计算尚未提供可用周期，不能据此判断时间。"
        elif _has_periods(key, raw, source):
            reason = "本次已返回周期，可作交叉核对；这不代表已完成多引擎验证。"
        else:
            reason = "本次适用性尚未核实，缺少可核对周期，不补写日期。"
        if applicable is True:
            reason += " 原适用性判定：适用。"
        reasons = list(dict.fromkeys(_reader_reason(str(value)) for value in (raw.get("reason"), source.get("reason")) if value))
        if reasons:
            reason += " 原因：" + "；".join(reasons)
        name = "Kala Chakra" if key == "kala_chakra" else key.replace("_", "-").title()
        lines.append(f"| {_cell(name)} | {_cell(reason)} | {BOUNDARY} |")
    return "\n".join(lines) + "\n"