/**
 * 코핑 배근 입력 (승인 2026-10-26, 제안 = RAG/코핑_입력범위_제안.md). The 12 numbers of the ③ 코핑 배근 입력 panel.
 * Defaults are the 코핑철근.md values; the ranges are the proposal's, pending the design-standard check.
 */
export interface CopingRebarSettings {
  /** 피복 (철근 중심, mm). */
  cover: number;
  /** 주철근 기본간격 (mm). */
  mainSpacing: number;
  /** 주철근 끝단 최소 여유 (mm). */
  mainEndGap: number;
  /** 상면 주철근 단 간격 · 세로 (mm). The horizontal step is fixed at d (H29, 28.6 mm). */
  mainLayerGap: number;
  /** 첫 전단철근 최소 여유 (피복 다음, mm). */
  firstShearGap: number;
  /** 전단철근 다리 수 (짝수). */
  shearLegs: number;
  /** 전단철근 간격 · 경사 (mm). */
  spacingS: number;
  /** 전단철근 간격 · Level (mm). */
  spacingL: number;
  /** 측면 수평 간격 (mm). */
  sideSpacing: number;
  /** 측면 위 끝 아래 최소 여유 (mm). */
  sideEndGap: number;
  /** C14 간격 위 2줄 (mm). */
  c14UpperSpacing: number;
  /** C14 간격 아래 줄 (mm). */
  c14LowerSpacing: number;
}

export const DEFAULT_COPING_REBAR: CopingRebarSettings = {
  cover: 100,
  mainSpacing: 125,
  mainEndGap: 80,
  mainLayerGap: 100,
  firstShearGap: 200,
  shearLegs: 6,
  spacingS: 250,
  spacingL: 300,
  sideSpacing: 250,
  sideEndGap: 400,
  c14UpperSpacing: 1000,
  c14LowerSpacing: 2000,
};

/** Allowed range per input (inclusive, mm). The shear legs are checked for evenness separately (CP02). */
export const COPING_REBAR_RANGES: Record<keyof CopingRebarSettings, [number, number]> = {
  cover: [80, 150],
  mainSpacing: [100, 150],
  mainEndGap: [60, 100],
  mainLayerGap: [80, 120],
  firstShearGap: [100, 300],
  shearLegs: [4, 8],
  spacingS: [200, 350],
  spacingL: [200, 350],
  sideSpacing: [200, 300],
  sideEndGap: [300, 500],
  c14UpperSpacing: [800, 1200],
  c14LowerSpacing: [1500, 2500],
};

/** 상면 주철근(C1–C6) 이음 (승인 2026-10-26): ignore = 이음 무시 (사양 기본), apply = 정척 초과 시 2조각 겹침. */
export type TopSpliceMode = 'ignore' | 'apply';
/** 이음 위치: center = 기둥 중심, end = 단부 (정척 안에서 가장 끝 쪽). */
export type TopSpliceAt = 'center' | 'end';

export interface TopSpliceSettings {
  mode: TopSpliceMode;
  at: TopSpliceAt;
}

export const DEFAULT_TOP_SPLICE: TopSpliceSettings = { mode: 'ignore', at: 'center' };

export interface CopingSettingsIssue {
  code: 'CP01' | 'CP02';
  key: keyof CopingRebarSettings;
  message: string;
}

/**
 * Checks the settings against the ranges. CP01: a value is not a finite number or is out of range (W).
 * CP02: the shear leg count is odd (the 폐합 bars come in pairs of legs).
 */
export function copingSettingsIssues(s: CopingRebarSettings): CopingSettingsIssue[] {
  const out: CopingSettingsIssue[] = [];
  for (const key of Object.keys(COPING_REBAR_RANGES) as (keyof CopingRebarSettings)[]) {
    const v = s[key];
    const [lo, hi] = COPING_REBAR_RANGES[key];
    if (!Number.isFinite(v) || v < lo || v > hi) {
      out.push({ code: 'CP01', key, message: `CP01 ${key} ${v} 범위 밖 (${lo}–${hi})` });
    }
  }
  if (Number.isFinite(s.shearLegs) && s.shearLegs % 2 !== 0) {
    out.push({ code: 'CP02', key: 'shearLegs', message: `CP02 전단철근 다리 수 ${s.shearLegs}는 홀수 (짝수만 허용)` });
  }
  return out;
}