/**
 * 철근재료표 (quantity table): bars grouped by 강종 (grade) and nominal diameter, with unit weights and totals.
 * Pure functions. Rows with no length yet are listed as missing and left out of the totals (no guessed lengths).
 */
import { fyOf, Material, NOMINAL_DIAMETER, type BarSize } from './common';
import type { RebarRow } from './summary';

/** Unit weight (kg/m) of a bar of nominal diameter d (mm): 0.00617 · d². H19 (19.1) → 2.25. */
export function unitWeight(dMm: number): number {
  return 0.00617 * dMm * dMm;
}

/** True for a 규격 that is a rebar size (H19, S32, D13 …), not a coupler label. */
export function isBarSize(size: string): size is BarSize {
  return size in NOMINAL_DIAMETER;
}

export interface QuantityLine {
  name: string;
  size: string;
  member: RebarRow['member'];
  /** 개수 as in the 철근표 row (bars; for P1 each bar is several pieces). */
  count: number;
  /** Pieces in the row: the sum of the piece counts (C9 108 = 18 positions × 6 pieces). */
  pieceCount: number;
  /** Length of one bar (mm), or null when the row has several lengths (see pieces). */
  length: number | null;
  pieces: { length: number; count: number }[];
  /** Total length (m) = count × length. */
  totalM: number;
  kgPerM: number;
  /** Total weight (kg) before the 할증. */
  kg: number;
  shape: string;
}

export interface QuantityDiameter {
  size: string;
  dMm: number;
  lines: QuantityLine[];
  totalM: number;
  kg: number;
}

export interface QuantityGroup {
  grade: number;
  diameters: QuantityDiameter[];
  kg: number;
}

export interface Quantity {
  groups: QuantityGroup[];
  couplers: { name: string; count: number }[];
  /** Bar names with no length yet; they are not in the totals. */
  missing: string[];
  kg: number;
  /** 할증 applied to the total, in percent (입력, 기본 0 가정). */
  wastePercent: number;
  kgWithWaste: number;
  ton: number;
}

export function buildQuantity(rows: RebarRow[], material: Material, incomplete: readonly string[] = []): Quantity {
  const byGrade = new Map<number, Map<string, QuantityDiameter>>();
  const couplers: { name: string; count: number }[] = [];
  const missing: string[] = [...incomplete];

  for (const r of rows) {
    if (r.name.includes('커플러')) {
      couplers.push({ name: r.name, count: r.count });
      continue;
    }
    if (!isBarSize(r.size) && r.diameterMm === undefined) continue;
    // A row with several lengths carries pieces; a row with one length is one piece (count bars of that length).
    const pieces = r.pieces ?? (r.length === null ? null : [{ length: r.length, count: r.count }]);
    if (!pieces) {
      missing.push(r.name);
      continue;
    }
    const grade = r.gradeMpa ?? fyOf(material, r.size as BarSize);
    const dMm = r.diameterMm ?? NOMINAL_DIAMETER[r.size as BarSize];
    const kgPerM = unitWeight(dMm);
    const pieceCount = pieces.reduce((s, p) => s + p.count, 0);
    const totalM = pieces.reduce((s, p) => s + (p.count * p.length) / 1000, 0);
    const line: QuantityLine = {
      name: r.name, size: r.size, member: r.member, count: r.count, pieceCount,
      length: pieces.length === 1 ? pieces[0].length : null, pieces, totalM, kgPerM, kg: totalM * kgPerM, shape: r.shape,
    };
    const diameters = byGrade.get(grade) ?? new Map<string, QuantityDiameter>();
    const sameDiameter = [...diameters.values()].find(d => Math.abs(d.dMm - dMm) < 1e-8);
    const d = sameDiameter ?? { size: r.size, dMm, lines: [], totalM: 0, kg: 0 };
    d.lines.push(line);
    d.totalM += totalM;
    d.kg += line.kg;
    diameters.set(d.size, d);
    byGrade.set(grade, diameters);
  }

  const groups: QuantityGroup[] = [...byGrade.entries()]
    .sort(([a], [b]) => a - b)
    .map(([grade, diameters]) => {
      const list = [...diameters.values()].sort((a, b) => a.dMm - b.dMm);
      return { grade, diameters: list, kg: list.reduce((s, d) => s + d.kg, 0) };
    });
  const kg = groups.reduce((s, g) => s + g.kg, 0);
  const wastePercent = material.waste;
  const kgWithWaste = kg * (1 + wastePercent / 100);
  return { groups, couplers, missing, kg, wastePercent, kgWithWaste, ton: kgWithWaste / 1000 };
}

/** The 철근재료표 as rows (for the Excel export): group and diameter headers, lines, subtotals, totals. */
export function quantityRows(q: Quantity): (string | number)[][] {
  const out: (string | number)[][] = [['강종', '번호', '형상', '규격', '원표 수량', '길이 (mm)', '총길이 (m)', '단위중량 (kg/m)', '총중량 (kg)', '가공 본수', '부재']];
  for (const g of q.groups) {
    for (const d of g.diameters) {
      for (const l of d.lines) {
        out.push([`SD${g.grade}`, l.name, l.shape, l.size, l.count, l.length === null ? '여러 길이' : round(l.length), round(l.totalM), round(l.kgPerM, 3), round(l.kg), l.pieceCount, l.member]);
      }
      out.push(['', `${d.size} 소계`, '', d.size, '', '', round(d.totalM), '', round(d.kg)]);
    }
    out.push([`SD${g.grade} 소계`, '', '', '', '', '', '', '', round(g.kg)]);
  }
  out.push([q.missing.length ? '계산된 부재 소계 · 전체 수량 미완료' : '합계', '', '', '', '', '', '', '', round(q.kg)]);
  out.push([`할증 ${q.wastePercent}% 포함`, '', '', '', '', '', '', '', round(q.kgWithWaste)]);
  out.push(['총중량 (ton)', '', '', '', '', '', '', '', round(q.ton, 3)]);
  for (const c of q.couplers) out.push(['커플러 (개수만)', c.name, '', '', c.count, '', '', '', '']);
  for (const name of q.missing) out.push(['미계산 · 합계 미완료', name]);
  return out;
}

function round(v: number, digits = 1): number {
  const f = 10 ** digits;
  return Math.round(v * f) / f;
}