// Budget (readme §5): an op + collider regeneration must stay under 2 ms on the server.
// Each iteration also steps the world, as the server does every tick: planck only
// flushes its broadphase move buffer during step(), and skipping it makes body
// destruction quadratic, which never happens in game.
import { World } from 'planck';
import { bench, describe } from 'vitest';
import { loadMap } from '../src/server/assets';
import { TerrainColliders } from '../src/server/physics/terrainColliders';
import { Rng } from '../src/shared/rng';
import { DetachFinder } from '../src/shared/terrain/detach';
import { extractContours } from '../src/shared/terrain/marchingSquares';
import { applyTerrainEvent } from '../src/shared/terrain/events';
import { applyOp } from '../src/shared/terrain/ops';
import { rleEncode } from '../src/shared/terrain/rle';
import { simplifyContour } from '../src/shared/terrain/simplify';
import { ASSETS, realMaterials } from './helpers';

const materials = realMaterials();
const { terrain } = loadMap(ASSETS, 'gateau-etages', materials);
const world = new World();
const colliders = new TerrainColliders(world, terrain);
colliders.rebuildDirty();
const rng = new Rng(7);
const finder = new DetachFinder(terrain);

// A copy of the map whose top tier has just been cut loose (search only, the bitmap is never modified).
const cut = loadMap(ASSETS, 'gateau-etages', materials).terrain;
for (let x = 760; x <= 1290; x += 12) applyOp(cut, { kind: 'carve', x, y: 462, r: 14, power: 99 }, materials);
const cutFinder = new DetachFinder(cut);

/** Removes detached components like the server does, so they are not found again. */
function removeDetached(region: { x0: number; y0: number; x1: number; y1: number }): void {
  for (const c of finder.find(region)) {
    const { x0, y0, x1, y1 } = c.bounds;
    applyTerrainEvent(terrain, { kind: 'detach', id: 0, x: x0, y: y0, w: x1 - x0, h: y1 - y0, mask: rleEncode(c.mask), debris: true }, materials);
  }
}

describe('terrain', () => {
  bench('carve r=40 + detach search + collider rebuild', () => {
    const { changed } = applyOp(terrain, { kind: 'carve', x: rng.int(300, 1700), y: rng.int(300, 900), r: 40, power: 99 }, materials);
    if (changed) removeDetached(changed);
    colliders.rebuildDirty();
    world.step(1 / 60);
  });

  bench('fill r=30 + detach search + collider rebuild', () => {
    const { changed } = applyOp(terrain, { kind: 'fill', x: rng.int(300, 1700), y: rng.int(300, 900), r: 30, material: 1 }, materials);
    if (changed) removeDetached(changed);
    colliders.rebuildDirty();
    world.step(1 / 60);
  });

  bench('marching squares + simplify, one 64 px chunk', () => {
    for (const c of extractContours(terrain, 1024, 704, 1088, 768)) simplifyContour(c, 0.8);
  });

  bench('detach search: a whole tier comes loose (~90k px)', () => {
    if (cutFinder.find({ x0: 746, y0: 448, x1: 1305, y1: 477 }).length === 0) throw new Error('expected a detached tier');
  });

  bench('full map collider build (map load)', () => {
    const w = new World();
    terrain.markDirty({ x0: 0, y0: 0, x1: terrain.width, y1: terrain.height });
    new TerrainColliders(w, terrain).rebuildDirty();
  });
});