import test from 'node:test';
import assert from 'node:assert/strict';

import {
  ENVIRONMENT_ISLANDS,
  environmentWindAt,
  routeWeatherAt,
  semiRandomWindPattern,
  stormFrontAt,
  velocityWithEnvironment,
} from '../src/environment-physics.js';

test('environment exposes collidable island geometry', () => {
  assert.equal(ENVIRONMENT_ISLANDS.length, 2);
  for (const island of ENVIRONMENT_ISLANDS) {
    assert.ok(island.radius > 0);
    assert.ok(island.turbulenceRadius > island.radius);
  }
});

test('semi-random wind varies strength and direction across weather windows', () => {
  const samples = [0, 16000, 32000, 48000, 64000]
    .map((timeMs) => semiRandomWindPattern(timeMs));

  const roundedStrengths = new Set(samples.map(({ strength }) => Math.round(strength * 10)));
  const roundedHeadings = new Set(samples.map(({ angle }) => Math.round(angle * 10)));

  assert.ok(roundedStrengths.size >= 3);
  assert.ok(roundedHeadings.size >= 3);
  for (const sample of samples) {
    assert.ok(sample.strength >= 4 && sample.strength < 28);
  }
});

test('semi-random wind changes smoothly instead of jumping each frame', () => {
  const before = semiRandomWindPattern(15950);
  const after = semiRandomWindPattern(16050);
  const vector = ({ angle, strength }) => ({
    x: Math.cos(angle) * strength,
    y: Math.sin(angle) * strength,
  });
  const a = vector(before);
  const b = vector(after);

  assert.ok(Math.hypot(b.x - a.x, b.y - a.y) < 2.5);
});

test('ambient wind changes over time and remains bounded', () => {
  const first = environmentWindAt({ x: 1200, y: 1200, timeMs: 0 });
  const later = environmentWindAt({ x: 1200, y: 1200, timeMs: 24000 });

  assert.ok(first.strength > 3 && first.strength < 55);
  assert.ok(later.strength > 3 && later.strength < 55);
  assert.notDeepEqual(
    [Math.round(first.x * 100), Math.round(first.y * 100)],
    [Math.round(later.x * 100), Math.round(later.y * 100)],
  );
});

test('islands produce a local turbulence contribution', () => {
  const island = ENVIRONMENT_ISLANDS[0];
  const near = environmentWindAt({
    x: island.x + island.radius + 20,
    y: island.y,
    timeMs: 6000,
  });
  const far = environmentWindAt({
    x: island.x + island.turbulenceRadius + 300,
    y: island.y,
    timeMs: 6000,
  });

  assert.notEqual(
    Math.round(near.strength * 100),
    Math.round(far.strength * 100),
  );
});

test('environment velocity adds wind according to exposure', () => {
  const result = velocityWithEnvironment(100, -20, { x: 12, y: 8 }, 0.5);

  assert.equal(result.x, 106);
  assert.equal(result.y, -16);
});


test('shipping lanes create calm cores with unstable edges and open sky beyond', () => {
  const routes = [{
    id: 'shipping-1',
    from: { x: 1000, y: 1200 },
    to: { x: 3600, y: 1200 },
    width: 220,
  }];
  const lane = routeWeatherAt({ x: 2200, y: 1200, routes });
  const edge = routeWeatherAt({ x: 2200, y: 1500, routes });
  const open = routeWeatherAt({ x: 2200, y: 2200, routes });

  assert.equal(lane.zone, 'shipping-lane');
  assert.ok(lane.routeInfluence > 0.9);
  assert.equal(edge.zone, 'route-edge');
  assert.ok(edge.routeEdge > lane.routeEdge);
  assert.equal(open.zone, 'open-sky');
  assert.ok(open.routeInfluence < 0.05);
});

test('moving storm fronts can cross the world independent of route corridors', () => {
  const timeMs = 110000 * 0.25;
  const intensity = stormFrontAt({
    x: 900,
    y: 5400 * 0.53,
    timeMs,
    worldWidth: 5400,
    worldHeight: 5400,
  });
  assert.ok(intensity > 0.75);
});

test('route-aware wind is calmer in a shipping lane than nearby open sky', () => {
  const routes = [{
    id: 'shipping-1',
    from: { x: 1000, y: 1000 },
    to: { x: 3600, y: 1000 },
    width: 220,
  }];
  const lane = environmentWindAt({
    x: 2200, y: 1000, timeMs: 0, routes, islands: [],
  });
  const open = environmentWindAt({
    x: 2200, y: 2200, timeMs: 0, routes, islands: [],
  });

  assert.equal(lane.zone, 'shipping-lane');
  assert.equal(open.zone, 'open-sky');
  assert.ok(lane.strength < open.strength);
});