import { test } from 'node:test';
import assert from 'node:assert/strict';
import {
  adjustGeometry,
  distanceMeters,
  distanceToGeometry,
  overlayAnchor,
  IDENTITY_OVERLAY,
  type AreaGeometry,
  type LonLat,
} from '../src/features/citymap/geo';
import bundled from '../src/features/citymap/parkingAreas.json';

/**
 * The city-map geometry, checked against the real bundled area set.
 *
 * This is the maths that decides which street you are tracking time on, so it is
 * tested against the actual 49 areas rather than toy shapes — the awkward cases
 * (an L-shaped run down two streets, a crescent-shaped beach lot) only exist in
 * the real data.
 *
 * Run with: npm test --workspace app
 */

interface Area {
  id: string;
  shape: 'line' | 'polygon';
  geometry: AreaGeometry;
}

const areas: Area[] = (bundled as any).features.map((f: any) => ({
  ...f.properties,
  geometry: f.geometry,
}));
const geoms: AreaGeometry[] = areas.map((a) => a.geometry);

/**
 * Points that genuinely lie on an area: edge midpoints. A centroid is no good —
 * an L-shaped run's lands mid-block and the crescent City Beach lot's lands in
 * the water.
 */
function onGeometry(g: AreaGeometry): LonLat[] {
  const rings = g.type === 'Polygon' ? g.coordinates : [g.coordinates];
  const out: LonLat[] = [];
  for (const r of rings) {
    for (let i = 1; i < r.length; i++) {
      out.push([(r[i - 1][0] + r[i][0]) / 2, (r[i - 1][1] + r[i][1]) / 2]);
    }
  }
  return out;
}

function nearest(p: LonLat): { area: Area; dist: number } {
  let best = areas[0];
  let bd = Infinity;
  for (const a of areas) {
    const d = distanceToGeometry(p, a.geometry);
    if (d < bd) {
      best = a;
      bd = d;
    }
  }
  return { area: best, dist: bd };
}

test('the bundled map has the expected shape', () => {
  assert.equal(areas.length, 49);
  assert.ok(areas.some((a) => a.shape === 'polygon'), 'city lots should be polygons');
  assert.ok(areas.some((a) => a.shape === 'line'), 'on-street runs should be lines');
});

test('a point on an area measures zero distance to it', () => {
  for (const a of areas) {
    for (const p of onGeometry(a.geometry)) {
      const d = distanceToGeometry(p, a.geometry);
      assert.ok(d < 0.01, `${a.id}: a point on it measured ${d.toFixed(3)} m away`);
    }
  }
});

test('hit-testing resolves each area from points on it', () => {
  for (const a of areas) {
    for (const p of onGeometry(a.geometry)) {
      const hit = nearest(p);
      if (hit.area.id === a.id) continue;
      // Categories meet at intersections, so an exact tie is acceptable; silently
      // resolving to something FURTHER away is the bug this guards against.
      assert.ok(
        hit.dist < 0.01,
        `${a.id}: a point on it resolved to ${hit.area.id} at ${hit.dist.toFixed(2)} m`,
      );
    }
  }
});

test('a point off the map does not snap to an area', () => {
  // East of the highway, across Sand Creek — no mapped parking anywhere near.
  assert.ok(nearest([-116.5445, 48.2705]).dist > 40);
});

test('the identity overlay is a no-op', () => {
  const anchor = overlayAnchor(geoms);
  for (const g of geoms) assert.deepEqual(adjustGeometry(g, IDENTITY_OVERLAY, anchor), g);
});

test('a shift moves every vertex by exactly that distance', () => {
  const anchor = overlayAnchor(geoms);
  for (const g of geoms) {
    const moved = adjustGeometry(g, { ...IDENTITY_OVERLAY, dxMeters: 10 }, anchor);
    const a = g.type === 'Polygon' ? g.coordinates[0] : g.coordinates;
    const b = moved.type === 'Polygon' ? moved.coordinates[0] : moved.coordinates;
    for (let i = 0; i < a.length; i++) {
      assert.ok(Math.abs(distanceMeters(a[i], b[i]) - 10) < 0.05, 'shift distance');
      assert.ok(b[i][0] > a[i][0], 'positive dxMeters must move east');
    }
  }
});

test('rotation is rigid about the anchor and 360° returns home', () => {
  const anchor = overlayAnchor(geoms);
  const g = geoms.find((x) => x.type === 'LineString') as Extract<
    AreaGeometry,
    { type: 'LineString' }
  >;

  const spun = adjustGeometry(g, { ...IDENTITY_OVERLAY, rotationDeg: 360 }, anchor) as typeof g;
  for (let i = 0; i < g.coordinates.length; i++) {
    assert.ok(distanceMeters(g.coordinates[i], spun.coordinates[i]) < 0.01, '360° round trip');
  }

  const rot = adjustGeometry(g, { ...IDENTITY_OVERLAY, rotationDeg: 5 }, anchor) as typeof g;
  for (let i = 0; i < g.coordinates.length; i++) {
    const r0 = distanceMeters(anchor, g.coordinates[i]);
    const r1 = distanceMeters(anchor, rot.coordinates[i]);
    assert.ok(Math.abs(r0 - r1) < 0.5, `rotation changed radius ${r0.toFixed(1)} -> ${r1.toFixed(1)}`);
  }
});

test('scale is anchored and proportional', () => {
  const anchor = overlayAnchor(geoms);
  const far = (geoms.find((x) => x.type === 'LineString') as any).coordinates[0] as LonLat;
  const scaled = adjustGeometry(
    { type: 'LineString', coordinates: [anchor, far] },
    { ...IDENTITY_OVERLAY, scale: 2 },
    anchor,
  ) as Extract<AreaGeometry, { type: 'LineString' }>;

  assert.ok(distanceMeters(scaled.coordinates[0], anchor) < 0.01, 'the anchor must not move');
  const before = distanceMeters(anchor, far);
  const after = distanceMeters(anchor, scaled.coordinates[1]);
  assert.ok(Math.abs(after - 2 * before) < 0.5, `×2: ${before.toFixed(1)} -> ${after.toFixed(1)}`);
});