houseplan-card/test/wall-thickness.test.mjs

// Wall thickness pure geometry (docs/WALL-THICKNESS.md §10).
import test from 'node:test';
import assert from 'node:assert/strict';
import {
  wallKey, lookupWall, thicknessCmAt, degradeWalls, rekeyWallsAfterMove,
  setWallThickness, setWallThicknessForRoom, clampWallCm, cmToField, fieldToCm,
  wallCmToUnits, insetContour, inwardNormal, edgeKinds, wallEdgeBodies,
  paperRoomShapesWithWalls, WALL_MIN_CM, WALL_MAX_CM, MITRE_LIMIT,
} from '../test-build/wall-thickness.js';
import { polygonArea, paperRoomShapes } from '../test-build/logic.js';
import { GRID_PITCH } from '../test-build/space-geometry.js';

const closeTo = (got, want, tol = 1e-6) =>
  assert.ok(Math.abs(got - want) <= tol, `expected ${want}, got ${got}`);

const pitch = 1 / 240; // normalised grid step
const cellCm = 5;

// ------------------------------- key ----------------------------------------

test('wallKey is the same from either end of the wall', () => {
  const a = [0.1, 0.2], b = [0.4, 0.2];
  assert.equal(wallKey(a, b, pitch), wallKey(b, a, pitch));
});

test('wallKey changes when the wall moves by one grid step', () => {
  const a = [0.1, 0.2], b = [0.4, 0.2];
  const a2 = [0.1, 0.2 + pitch], b2 = [0.4, 0.2 + pitch];
  assert.notEqual(wallKey(a, b, pitch), wallKey(a2, b2, pitch));
});

test('lookupWall finds an entry and thicknessCmAt reads it', () => {
  const a = [0.1, 0.2], b = [0.4, 0.2];
  const walls = [{ key: wallKey(a, b, pitch), cm: 20 }];
  assert.equal(lookupWall(walls, a, b, pitch)?.cm, 20);
  assert.equal(lookupWall(walls, b, a, pitch)?.cm, 20);
  assert.equal(thicknessCmAt(walls, a, b, pitch), 20);
  assert.equal(thicknessCmAt(walls, [0, 0], [1, 1], pitch), 0);
});

// ------------------------------- units --------------------------------------

test('cm ↔ field: metric stays cm, imperial is inches', () => {
  assert.equal(cmToField(25.4, false), '25.4');
  assert.equal(cmToField(25.4, true), '10');
  assert.equal(fieldToCm('10', true), 25.4);
  assert.equal(fieldToCm('20', false), 20);
  assert.equal(fieldToCm('', false), null);
  assert.equal(fieldToCm('0', true), null);
  assert.equal(clampWallCm(0.5), WALL_MIN_CM);
  assert.equal(clampWallCm(999), WALL_MAX_CM);
});

test('wallCmToUnits goes through cell_cm like every other length', () => {
  // 5 cm at 5 cm/cell and pitch P → 1 cell = P units
  closeTo(wallCmToUnits(5, 5, GRID_PITCH), GRID_PITCH);
  closeTo(wallCmToUnits(10, 5, GRID_PITCH), 2 * GRID_PITCH);
});

// ------------------------------- degrade / rekey ----------------------------

test('degradeWalls drops a key with no matching room edge', () => {
  const rooms = [{ id: 'r1', poly: [[0, 0], [1, 0], [1, 1], [0, 1]] }];
  const live = wallKey([0, 0], [1, 0], pitch);
  const walls = [
    { key: live, cm: 15 },
    { key: '0.00,0.00@9.9999', cm: 10 },
  ];
  const kept = degradeWalls(walls, rooms, pitch);
  assert.equal(kept.length, 1);
  assert.equal(kept[0].key, live);
});

test('rekeyWallsAfterMove rewrites the key when a span shifts by one cell', () => {
  const oldA = [0.1, 0.2], oldB = [0.4, 0.2];
  const newA = [0.1, 0.2 + pitch], newB = [0.4, 0.2 + pitch];
  const walls = [{ key: wallKey(oldA, oldB, pitch), cm: 18 }];
  const next = rekeyWallsAfterMove(walls, [[oldA, oldB]], [[newA, newB]], pitch);
  assert.equal(next.length, 1);
  assert.equal(next[0].key, wallKey(newA, newB, pitch));
  assert.equal(next[0].cm, 18);
});

test('setWallThickness upserts and removes', () => {
  const a = [0, 0], b = [1, 0];
  let walls = setWallThickness([], a, b, 12, pitch);
  assert.equal(walls.length, 1);
  walls = setWallThickness(walls, a, b, 30, pitch);
  assert.equal(walls[0].cm, 30);
  walls = setWallThickness(walls, a, b, null, pitch);
  assert.equal(walls.length, 0);
});

test('setWallThicknessForRoom skips open cuts', () => {
  const room = { id: 'r', poly: [[0, 0], [1, 0], [1, 1], [0, 1]] };
  const open = [[0, 0, 1, 0]];
  const walls = setWallThicknessForRoom([], room, 20, pitch, open);
  // three edges get thickness; the open bottom does not
  assert.equal(walls.length, 3);
  assert.equal(thicknessCmAt(walls, [0, 0], [1, 0], pitch), 0);
  assert.equal(thicknessCmAt(walls, [1, 0], [1, 1], pitch), 20);
});

// ------------------------------- inset --------------------------------------

test('insetContour: rectangle inset by half-thickness on every side', () => {
  const poly = [[0, 0], [10, 0], [10, 6], [0, 6]];
  const inset = insetContour(poly, [1, 1, 1, 1]);
  assert.ok(inset && inset.length >= 4);
  // area of a 10×6 rect inset by 1 → 8×4 = 32
  closeTo(polygonArea(inset), 32, 0.05);
});

test('insetContour: one thick edge among thin ones', () => {
  const poly = [[0, 0], [10, 0], [10, 6], [0, 6]];
  // only bottom edge (i=0) has offset 2
  const inset = insetContour(poly, [2, 0, 0, 0]);
  assert.ok(inset);
  // bottom moves up; area shrinks by roughly 2×10 = 20
  assert.ok(polygonArea(inset) < polygonArea(poly) - 15);
});

test('insetContour: L-shape stays a simple polygon', () => {
  const poly = [[0, 0], [6, 0], [6, 2], [2, 2], [2, 6], [0, 6]];
  const inset = insetContour(poly, [0.5, 0.5, 0.5, 0.5, 0.5, 0.5]);
  assert.ok(inset && inset.length >= 6);
  assert.ok(polygonArea(inset) < polygonArea(poly));
  assert.ok(polygonArea(inset) > 0);
});

test('insetContour: acute corner falls back to a bevel (no infinite spike)', () => {
  // very sharp tip at the origin
  const poly = [[0, 0], [10, 0.3], [10, 0], [0, 0]];
  // degenerate — use a proper acute triangle
  const sharp = [[0, 0], [10, 1], [10, -1]];
  const offsets = [1, 1, 1];
  const inset = insetContour(sharp, offsets);
  assert.ok(inset);
  for (const p of inset) {
    const dist = Math.hypot(p[0], p[1]);
    // no vertex may fly farther than MITRE_LIMIT × thickness from origin-ish
    assert.ok(dist < 10 + MITRE_LIMIT * 1 + 1, `spike at ${p}`);
  }
});

test('inwardNormal points into the rectangle', () => {
  const poly = [[0, 0], [10, 0], [10, 6], [0, 6]];
  const [nx, ny] = inwardNormal(poly, 0); // bottom edge → should point +y
  assert.ok(ny > 0.5, `expected +y inward, got ${nx},${ny}`);
});

// ------------------------------- bodies / paper -----------------------------

test('wallEdgeBodies: shared wall is one full-depth quad, outer is inward', () => {
  const rooms = [
    { id: 'a', poly: [[0, 0], [5, 0], [5, 4], [0, 4]] },
    { id: 'b', poly: [[5, 0], [10, 0], [10, 4], [5, 4]] },
  ];
  // shared vertical at x=5
  const sharedKey = wallKey([5, 0], [5, 4], pitch);
  const outerKey = wallKey([0, 0], [5, 0], pitch);
  const walls = [
    { key: sharedKey, cm: 20 },
    { key: outerKey, cm: 30 },
  ];
  const kindsA = edgeKinds(rooms, 'a', [], pitch);
  assert.ok(kindsA.includes('shared'));
  assert.ok(kindsA.includes('outer'));

  const bodies = wallEdgeBodies(rooms, walls, [], pitch, cellCm, pitch);
  const shared = bodies.find((b) => b.key === sharedKey);
  const outer = bodies.find((b) => b.key === outerKey);
  assert.ok(shared, 'shared body missing');
  assert.ok(outer, 'outer body missing');
  assert.equal(shared.kind, 'shared');
  assert.equal(outer.kind, 'outer');
  // only one body per key even though two rooms see the shared wall
  assert.equal(bodies.filter((b) => b.key === sharedKey).length, 1);
});

test('paper with walls covers shared centreline; without walls matches paperRoomShapes', () => {
  const rooms = [
    { id: 'a', poly: [[0, 0], [5, 0], [5, 4], [0, 4]] },
    { id: 'b', poly: [[5, 0], [10, 0], [10, 4], [5, 4]] },
  ];
  const plain = paperRoomShapes(rooms);
  const same = paperRoomShapesWithWalls(rooms, [], [], pitch, cellCm, pitch);
  assert.deepEqual(same, plain);

  const walls = [{ key: wallKey([5, 0], [5, 4], pitch), cm: 20 }];
  const grown = paperRoomShapesWithWalls(rooms, walls, [], pitch, cellCm, pitch);
  assert.equal(grown.length, 2);
  // grown polys are still present (strings)
  assert.ok('poly' in grown[0]);
});

test('area of the room polygon is unchanged by thickness helpers', () => {
  const poly = [[0, 0], [8, 0], [8, 5], [0, 5]];
  const before = polygonArea(poly);
  insetContour(poly, [0.5, 0.5, 0.5, 0.5]);
  assert.equal(polygonArea(poly), before);
});