Pier_v1/src/core/rebar/column.ts

import { DEFAULT_MATERIAL, developmentLength, fyOf, hookLength, Material, NOMINAL_DIAMETER, spliceLength } from './common';
import { layers } from './footing';

/**
 * 기둥 철근 C4 (plan C4). Source: RAG/기둥철근 (1).md, 2026-10-22 최종 정리. Type-1 원형 중실 기둥.
 * Lengths in mm, heights in mm from the 확대기초 상면 (up +).
 */
export interface ColumnInput {
  /** 기둥 지름 D. */
  D: number;
  /** 기둥 높이 H_c (확대기초 상면 ~ 코핑 Level 하면). */
  Hc: number;
  /** 기둥 중심 위치의 코핑 높이 h_cop. */
  hcop: number;
  /** 기둥 면 ~ P1 중심 피복 c. */
  c: number;
  /** P1 위 끝의 코핑 상면 아래 깊이 e_P1. */
  eP1: number;
  /** 띠철근 구간 위 끝의 코핑 상면 아래 깊이 e_top. */
  eTop: number;
  /** 확대기초 깊이 H_f (for P4). */
  Hf: number;
  /** 주철근 원주 등분 수 n_div. */
  nDiv: number;
  /** 주철근 커플러 간격 (확대기초 상면부터). */
  ctcCoupler: number;
  /** P2 커플러를 P1보다 올리는 높이. */
  dzCp2: number;
  ctcP3: number;
  ctcP5: number;
  ctcP4: number;
  /** P4 구간 깊이 비율 r_P4. */
  rP4: number;
  ctcP6: number;
}

/** 예제 운곡교 P1 (기둥철근.md §1.2 기본값). */
export const COLUMN_P1: ColumnInput = {
  D: 2000,
  Hc: 12703,
  hcop: 2644,
  c: 125,
  eP1: 200,
  eTop: 1623,
  Hf: 2000,
  nDiv: 46,
  ctcCoupler: 3000,
  dzCp2: 150,
  ctcP3: 300,
  ctcP5: 120,
  ctcP4: 120,
  rP4: 0.5,
  ctcP6: 1800,
};

/** A bar in the 확대기초 top layer, height from the 확대기초 상면 (mm, negative = below). */
export interface TopBar {
  name: string;
  z: number;
  d: number;
}

/**
 * RB-C07 (기둥철근.md §6.1–6.2, 결정): a P4 that interferes with a 확대기초 top bar is deleted.
 * Interference: |z_P4 − z_bar| < (d_P4 + d_bar)/2. Only the top layer (B5, B1) is checked; the assembly bars
 * B11/B12 are not, by the 2026-10-22 decision (Q-C9 무시).
 */
export function deleteInterferingP4(p4: number[], topBars: TopBar[], dP4: number = NOMINAL_DIAMETER.H19): { kept: number[]; deleted: { z: number; bar: string }[] } {
  const kept: number[] = [];
  const deleted: { z: number; bar: string }[] = [];
  for (const z of p4) {
    const hit = topBars.find((b) => Math.abs(z - b.z) < (dP4 + b.d) / 2);
    if (hit) deleted.push({ z, bar: hit.name });
    else kept.push(z);
  }
  return { kept, deleted };
}

/** Top-layer bars of the footing as heights from its 상면 (B5 and B1, §4.2). */
export function footingTopBars(Hf: number): TopBar[] {
  const z = layers(Hf);
  return [
    { name: 'B5', z: z.B5 - Hf, d: NOMINAL_DIAMETER.S29 },
    { name: 'B1', z: z.B1 - Hf, d: NOMINAL_DIAMETER.S25 },
  ];
}

const dS32 = NOMINAL_DIAMETER.S32;
const dH19 = NOMINAL_DIAMETER.H19;
const dH16 = NOMINAL_DIAMETER.H16;
const round = (v: number, d = 1) => Math.round(v * 10 ** d) / 10 ** d;

export function columnRebar(x: ColumnInput = COLUMN_P1, m: Material = DEFAULT_MATERIAL) {
  // P1 and P2 main bars (기둥철근.md §3)
  const r1 = x.D / 2 - x.c;
  const r2 = r1 - dS32;
  const zTop1 = x.Hc + x.hcop - x.eP1;
  const lD2 = developmentLength(dS32, fyOf(m, 'S32'), m.fck);
  const zTop2 = x.Hc + lD2;
  // Bottom of P1 and P2: 확대기초 하면 2단 (B7) 위 + (d_B7 + d_P1)/2 (기둥철근.md §3.2, the same for both).
  const zBot = -x.Hf + layers(x.Hf).B7 + (NOMINAL_DIAMETER.S19 + dS32) / 2;
  const couplerLevels = Array.from({ length: Math.max(0, Math.floor(zTop1 / x.ctcCoupler) - 1) }, (_, i) => (i + 1) * x.ctcCoupler);
  // Pieces of each main bar between its couplers (기둥철근.md §3.2): the bottom piece carries the 90° hook (16.5·d = 525).
  const p1Hook = Math.round(hookLength('main90', dS32));
  const p1Points = [zBot, ...couplerLevels, zTop1];
  const p1Pieces = p1Points.slice(1).map((z, i) => round(z - p1Points[i] + (i === 0 ? p1Hook : 0)));
  const p2Points = [zBot, ...couplerLevels.map((z) => z + x.dzCp2), zTop2];
  const p2Pieces = p2Points.slice(1).map((z, i) => round(z - p2Points[i]));
  const couplersP1 = couplerLevels.length;
  const mainLines = x.nDiv;
  const mainP1 = mainLines * (couplersP1 + 1);
  const mainP2 = mainLines * (couplersP1 + 1);
  const couplers = couplersP1 * x.nDiv * 2;

  // Ties (기둥철근.md §4–§6)
  // Tie radius r_t = r_1 + (d_P1 + d_P3)/2 (기둥철근.md §4.1)
  const tieRadius = r1 + (dS32 + dH19) / 2;
  const zTopT = x.Hc + x.hcop - x.eTop;
  const lEmin = Math.max(x.D, zTopT / 6, 450);
  const n5 = Math.floor(lEmin / x.ctcP5);
  const lE = Math.max(lEmin, n5 * x.ctcP5 + x.ctcP5 / 2);
  const p3 = Array.from({ length: Math.floor((zTopT - lE) / x.ctcP3) + 1 }, (_, k) => lE + k * x.ctcP3);
  const n5all = Math.floor(lE / x.ctcP5);
  const p5 = Array.from({ length: n5all }, (_, j) => lE - (j + 1) * x.ctcP5);
  const z5last = lE - n5all * x.ctcP5;
  const m4 = Math.floor((z5last + x.rP4 * x.Hf) / x.ctcP4);
  const p4All = Array.from({ length: m4 }, (_, j) => z5last - (j + 1) * x.ctcP4);
  const p4Check = deleteInterferingP4(p4All, footingTopBars(x.Hf));
  const p4 = p4Check.kept;

  // P6 crossties (기둥철근.md §7): 4 bars per 단, from the first kept P4
  const z4first = p4.length ? p4[0] : z5last;
  const p6Levels: number[] = [];
  for (let z = z4first; z <= x.Hc; z += x.ctcP6) p6Levels.push(z);
  const p6Straight = 2 * tieRadius;
  const p6Hook = hookLength('tie90', dH16);
  const p6Length = p6Straight + 2 * Math.round(p6Hook); // 135 mm per hook, as in the document

  // P3 lap: Q-C6 is open; recommended = 1.3·l_d of H19 with the material inputs.
  const lapP3 = spliceLength(dH19, fyOf(m, 'H19'), m.fck);
  const p3Length = 2 * Math.PI * tieRadius + lapP3;
  const p5Length = 2 * Math.PI * tieRadius;

  return {
    p3Length: round(p3Length, 1),
    p5Length: round(p5Length, 1),
    lapP3: round(lapP3, 1),
    r1: round(r1),
    r2: round(r2),
    angleStepDeg: 360 / x.nDiv,
    zTop1: round(zTop1),
    zTop2: round(zTop2),
    zBot: round(zBot, 2),
    p1Hook,
    p1Pieces,
    p2Pieces,
    couplerP1: couplerLevels,
    couplerP2: couplerLevels.map((z) => z + x.dzCp2),
    mainP1,
    mainP2,
    couplers,
    tieRadius: round(tieRadius, 2),
    tieCircumference: round(2 * Math.PI * tieRadius, 1),
    zTopT: round(zTopT),
    lEmin: round(lEmin),
    lE: round(lE),
    p3,
    p5,
    p4,
    p6Levels,
    p6Count: p6Levels.length * 4,
    p6Length: round(p6Length, 1),
    p4SemicircleLength: round(Math.PI * tieRadius, 1),
    p3Count: p3.length,
    p5Count: p5.length,
    p4Count: p4.length,
    p4Deleted: p4Check.deleted,
  };
}