lunisolar/src/plugins/theGods/gods/by12Gods.ts

专业农历库，支持公历阴历互转，支持各类黄历数据查询，如八字四柱、阴历、神煞宜忌、时辰吉凶、建除十二神、胎神占方、五行纳音等。支持自定义插件。

/*
by12Gods (black & yellow 12 gods)

黄黑12神

道远几时通达，路遥何日还乡。
```
青龙明堂与天刑，朱雀金匮天德神；
白虎玉堂天牢黑，玄武司命惊勾陈。
```

*/

import { getBranchValue } from '../../../utils'
import { getCheckGodFunc } from '../utils'

export const by12GodNames = [
  '青龍',
  '明堂',
  '天刑',
  '朱雀',
  '金匱',
  '天德', //index = 5 當為時神時，名寶光
  '白虎',
  '玉堂',
  '天牢',
  '玄武',
  '司命',
  '勾陳',
  '寶光'
] as const

type By12Gods = { [key in (typeof by12GodNames)[number]]: GodDictItem }

/**
 ```
 青龍 明堂 金匱 寶光 玉堂 司命 與吉神并則從所宜，與凶神并， 則從所忌
 ```
 */
const by12GodData: {
  [key in (typeof by12GodNames)[number]]: [string[] | null, string[] | null, number]
} = {
  青龍: [null, null, 1],
  明堂: [null, null, 1],
  天刑: [null, null, -1],
  朱雀: [null, null, -1],
  金匱: [null, null, 1],
  天德: [null, null, 1],
  白虎: [null, null, -1],
  玉堂: [null, null, 1],
  天牢: [null, null, -1],
  玄武: [null, null, -1],
  司命: [null, null, 1],
  勾陳: [null, null, -1],
  寶光: [null, null, 1]
}

/**
 * 
 ```
 子午青龙起在申，卯酉之日又在寅。
  寅申须从子上起，巳亥在午不须论。
  唯有辰戌归辰位，丑未原从戌上寻。
 ```
 */
const dragonStart = [8, 10, 0, 2, 4, 6] // 申戌子寅辰午

export function theBy12Gods(offset: number, defaultYmdh: YMDH = 'month'): GodDictItem {
  const order = dragonStart // 申戌子寅辰午
  const godKey = by12GodNames[offset]
  return [
    getCheckGodFunc(
      (lsr: lunisolar.Lunisolar, ymdh: YMDH = defaultYmdh) =>
        (order[getBranchValue(lsr, ymdh) % 6] + offset) % 12,
      getBranchValue
    ),
    by12GodData[godKey][0],
    by12GodData[godKey][1],
    4
  ]
}

export const getBy12GodKeyByIdx = (idx: number, toYmdh: YMDH) => {
  return idx === 5 && toYmdh === 'hour' ? '寶光' : by12GodNames[idx]
}

export const createBy12Gods = (defaultYmdh: YMDH = 'month'): By12Gods => {
  const by12Gods: By12Gods = {} as By12Gods
  for (let idx = 0; idx < 12; idx++) {
    const item = getBy12GodKeyByIdx(idx, defaultYmdh === 'day' ? 'hour' : 'day')
    by12Gods[item] = theBy12Gods(Number(idx), defaultYmdh)
  }
  return by12Gods
}

export const getBy12GodIdx = (
  fromBv: number,
  toBv: number,
  toYmdh: YMDH = 'day'
): [number, string] => {
  const offset = 12 - dragonStart[fromBv % 6]
  const godIdx = (toBv + offset) % 12
  const godKey = getBy12GodKeyByIdx(godIdx, toYmdh)
  return [godIdx, godKey]
}

export const getBy12GodDataByKey = (key: string) => {
  return by12GodData.hasOwnProperty(key) ? by12GodData[key as (typeof by12GodNames)[number]] : null
}

/**
 * @param lsr The instance of Lunisolar
 * @returns [黃黑12神索引, 名稱，宜[], 忌[]]
 */
export function getBy12God(
  lsr: lunisolar.Lunisolar,
  fromYmdh: YMDH,
  toYmdh: YMDH
): [number, string, string[] | null, string[] | null, number] {
  const fromBv = getBranchValue(lsr, fromYmdh)
  const toBv = getBranchValue(lsr, toYmdh)
  const offset = 12 - dragonStart[fromBv % 6]
  const godIdx = (toBv + offset) % 12
  const godKey = getBy12GodKeyByIdx(godIdx, toYmdh)
  const [good, bad, luckLevel] = by12GodData[godKey]
  return [godIdx, godKey, good, bad, luckLevel]
}