import { describe, expect, it } from 'vitest';
import { readFileSync } from 'node:fs';
import { fileURLToPath } from 'node:url';
import * as XLSX from 'xlsx';
import { parseWorkbook } from '../src/core/parseWorkbook';
import { buildPier, DIM, defaultLevelWidthMm } from '../src/core/geometry';
import type { PierInput } from '../src/core/types';

// 산외교 P11 (샘플01) with the coping bent 8.767° at IP4 (2026-11-10 검토): back ⑥ g 11.64, ⑦ g 18.49, kink g 15.14.
const SAMPLE = fileURLToPath(new URL('../project_data/01_엑셀/샘플01_산외교_교각입력데이터.xlsx', import.meta.url));

function p11(): PierInput {
  const wb = XLSX.read(readFileSync(SAMPLE), { type: 'buffer' });
  wb.Sheets['IP']['F46'] = { t: 'n', v: 8.767 };
  const input = parseWorkbook(wb).piers.find((p) => p.name === 'P11')!;
  return { ...input, levelWidthMm: input.levelWidthMm ?? defaultLevelWidthMm(input.type, 2000) };
}

const kinkOf = (m: ReturnType<typeof buildPier>) => m.stretches[1].base;
const gOf = (m: ReturnType<typeof buildPier>, no: number) => m.bearings.find((b) => b.no === no)!.g;

describe('꺾임점 근처 계단 경계 (A, 2026-11-10)', () => {
  it('a back boundary 0.07 m from the kink moves onto the kink (⑥|⑦)', () => {
    const m = buildPier(p11());
    const kink = kinkOf(m);
    const own = (gOf(m, 6) + gOf(m, 7)) / 2;
    expect(Math.abs(own - kink)).toBeLessThan(0.1);
    expect(m.backSegments![2].s0).toBeCloseTo(kink, 9);
    expect(m.backSegments![1].s1).toBeCloseTo(kink, 9);
  });

  it('boundaries far from the kink stay midway between their bearings', () => {
    const m = buildPier(p11());
    expect(m.backSegments![1].s0).toBeCloseTo((gOf(m, 5) + gOf(m, 6)) / 2, 9);
    expect(m.backSegments![3].s0).toBeCloseTo((gOf(m, 7) + gOf(m, 8)) / 2, 9);
    m.segments.slice(1).forEach((seg) => expect(Math.abs(seg.s0 - kinkOf(m))).toBeGreaterThan(DIM.blockSize / 2));
  });

  it('no snap when a bearing would end up closer than half a block to the kink', () => {
    const input = p11();
    const base = buildPier(input);
    // ⑦ 0.4 m past the kink, ⑥ 0.6 m before it: midpoint 0.1 m before the kink, but ⑦ is within half a block.
    const u1 = base.stretches[1].u;
    const u0 = base.stretches[0].u;
    const kink = kinkOf(base);
    const d7 = kink + 0.4 - gOf(base, 7);
    const d6 = kink - 0.6 - gOf(base, 6);
    const bearings = input.bearings.map((b) =>
      b.no === 7 ? { ...b, x: b.x + d7 * u1.e, y: b.y + d7 * u1.n } : b.no === 6 ? { ...b, x: b.x + d6 * u0.e, y: b.y + d6 * u0.n } : b);
    const m = buildPier({ ...input, bearings });
    const own = (gOf(m, 6) + gOf(m, 7)) / 2;
    expect(kinkOf(m) - own).toBeCloseTo(0.1, 3);
    expect(m.backSegments![2].s0).toBeCloseTo(own, 9);
  });
});

describe('전·후열 나눔선 하나 (B, 2026-11-10)', () => {
  const split = (m: ReturnType<typeof buildPier>, k: number) => {
    const [front] = m.copingParts.filter((p) => p.k === k);
    return Math.abs(front.nFrom) < Math.abs(front.nTo) ? front.nFrom : front.nTo;
  };
  const meanN = (m: ReturnType<typeof buildPier>, row: string, k?: number) => {
    const rows = m.bearings.filter((b) => b.row === row && (k === undefined || b.k === k));
    return rows.reduce((s, b) => s + b.n, 0) / rows.length;
  };

  it('both stretches use the same line, the mean of the two rows over the whole pier (no jog at the kink)', () => {
    const m = buildPier(p11());
    expect(m.copingParts).toHaveLength(4);
    const nAll = (meanN(m, '전열') + meanN(m, '후열')) / 2;
    expect(split(m, 0)).toBeCloseTo(nAll, 9);
    expect(split(m, 1)).toBeCloseTo(nAll, 9);
    // Per stretch the lines would differ by about 0.16 m.
    const per = (k: number) => (meanN(m, '전열', k) + meanN(m, '후열', k)) / 2;
    expect(Math.abs(per(0) - per(1))).toBeGreaterThan(0.1);
  });

  it('falls back to a line per stretch when a bearing would be closer than half a block to the common line', () => {
    const input = p11();
    const base = buildPier(input);
    const nrm = base.stretches[1].nrm;
    // Move back ⑦ towards the axis (+n side here is the front), to n ≈ +0.1.
    const b7 = base.bearings.find((b) => b.no === 7)!;
    const d = 0.1 - b7.n;
    const bearings = input.bearings.map((b) => (b.no === 7 ? { ...b, x: b.x + d * nrm.e, y: b.y + d * nrm.n } : b));
    const m = buildPier({ ...input, bearings });
    const nAll = (meanN(m, '전열') + meanN(m, '후열')) / 2;
    expect(m.bearings.some((b) => Math.abs(b.n - nAll) < DIM.blockSize / 2)).toBe(true);
    for (const k of [0, 1]) expect(split(m, k)).toBeCloseTo((meanN(m, '전열', k) + meanN(m, '후열', k)) / 2, 9);
  });
});