divination/interpret.py

"""排盘到文字解读的胶水层。"""
from __future__ import annotations

from dataclasses import dataclass, asdict
from typing import Any

from .coin import Cast
from .hexagram import Hexagram, TRIGRAM_ELEMENT
from bazi.five_elements import describe_relation

RELATION_TO_LIUQIN = {
    "同类": "兄弟",
    "我生": "子孙",
    "生我": "父母",
    "我克": "妻财",
    "克我": "官鬼",
}

LIU_SHEN_ORDER = ("青龙", "朱雀", "勾陈", "螣蛇", "白虎", "玄武")

GAN_TO_LIU_SHEN_START = {
    "甲": 0, "乙": 0,
    "丙": 1, "丁": 1,
    "戊": 2, "己": 2,
    "庚": 3, "辛": 3,
    "壬": 4, "癸": 4,
}

LINE_TITLE = {1: "初", 2: "二", 3: "三", 4: "四", 5: "五", 6: "上"}


class LineReading:
    index: int
    title: str
    kind: str
    is_yang: bool
    is_changing: bool
    element: str
    liu_qin: str
    liu_shen: str
    bian: str

    def __init__(self, **kw):
        for k, v in kw.items():
            setattr(self, k, v)

    def to_dict(self):
        return self.__dict__


class CastReading:
    cast: Cast
    ben: Hexagram
    bian: Hexagram
    changing_indices: list
    lines: list
    element: str
    day_gan: str
    summary: str

    def __init__(self, **kw):
        for k, v in kw.items():
            setattr(self, k, v)

    def to_dict(self):
        """递归把 namedtuple / LineReading 全部转为 dict, 方便模板层使用。"""
        ben = self.ben
        bian = self.bian
        return {
            "cast": self.cast.to_dict() if hasattr(self.cast, "to_dict") else None,
            "ben": ben._asdict() if isinstance(ben, tuple) and hasattr(ben, "_asdict") else ben,
            "bian": bian._asdict() if isinstance(bian, tuple) and hasattr(bian, "_asdict") else bian,
            "changing_indices": list(self.changing_indices or []),
            "lines": [ln.to_dict() if hasattr(ln, "to_dict") else ln for ln in (self.lines or [])],
            "element": self.element,
            "day_gan": self.day_gan,
            "question": getattr(self, "question", "") or "",
            "summary": getattr(self, "summary", "") or "",
        }


def _line_element(line_idx: int, hexagram: Hexagram) -> str:
    if line_idx <= 3:
        return TRIGRAM_ELEMENT[hexagram.lower]
    return TRIGRAM_ELEMENT[hexagram.upper]


def _liu_qin(hex_el: str, line_el: str) -> str:
    return RELATION_TO_LIUQIN.get(describe_relation(hex_el, line_el), "—")


def _liu_shen(day_gan: str, line_idx: int) -> str:
    start = GAN_TO_LIU_SHEN_START.get(day_gan, 0)
    return LIU_SHEN_ORDER[(start + line_idx - 1) % 6]


def build_reading(cast: Cast, day_gan: str = "甲") -> CastReading:
    hex_el = cast.ben_hex.element
    lines = []
    for ln in cast.lines:
        el = _line_element(ln.index, cast.ben_hex)
        bian_kind = ""
        if ln.is_changing:
            bian_kind = "变为阳" if not ln.is_yang else "变为阴"
        lines.append(LineReading(
            index=ln.index,
            title=LINE_TITLE[ln.index],
            kind=ln.kind,
            is_yang=ln.is_yang,
            is_changing=ln.is_changing,
            element=el,
            liu_qin=_liu_qin(hex_el, el),
            liu_shen=_liu_shen(day_gan, ln.index),
            bian=bian_kind,
        ))
    return CastReading(
        cast=cast,
        ben=cast.ben_hex,
        bian=cast.bian_hex,
        changing_indices=cast.changing_indices,
        lines=lines,
        element=hex_el,
        day_gan=day_gan,
        question=getattr(cast, "question", ""),
    )