import assert from "node:assert/strict";
import { readFile } from "node:fs/promises";
import test from "node:test";
import {
  gridShouldBeVisible,
  resolveGridMode,
  selectGridLod,
  snapGridCenter,
} from "../apps/catalog/src/mapGridPolicy.mjs";

const settings = {
  gridVisible: true,
  gridLodEnabled: true,
  gridLod1MaxHeightKm: 10,
  gridLod1StepKm: 1,
  gridLod1Mode: "3d",
  gridLod2MaxHeightKm: 50,
  gridLod2StepKm: 5,
  gridLod2Mode: "3d",
  gridLod3MaxHeightKm: 180,
  gridLod3StepKm: 25,
  gridLod3Mode: "3d",
  gridLod4MaxHeightKm: 700,
  gridLod4StepKm: 100,
  gridLod4Mode: "graticule",
  gridLod5StepKm: 500,
  gridLod5Mode: "graticule",
  grid3dEnabled: true,
  gridGraticuleEnabled: true,
  gridMax3dViewAngleDegrees: 30,
  gridAutoDisableHeightKm: 10_000,
  gridCenterMode: "camera",
  gridTileSizeKm: 10,
};

test("five grid LODs preserve the close 3D and distant graticule contract", () => {
  assert.deepEqual(
    [5, 40, 120, 500, 2_000].map((height) => {
      const band = selectGridLod(settings, height);
      return [band.id, band.stepKm, band.mode];
    }),
    [
      ["lod-1", 1, "3d"],
      ["lod-2", 5, "3d"],
      ["lod-3", 25, "3d"],
      ["lod-4", 100, "graticule"],
      ["lod-5", 500, "graticule"],
    ],
  );
});

test("LOD hysteresis holds the previous band around a threshold", () => {
  assert.equal(selectGridLod(settings, 10.5, 0).id, "lod-1");
  assert.equal(selectGridLod(settings, 10.9, 0).id, "lod-2");
  assert.equal(selectGridLod(settings, 9.5, 1).id, "lod-2");
  assert.equal(selectGridLod(settings, 9.1, 1).id, "lod-1");
});

test("oblique close view falls back to the graticule without dropping the grid", () => {
  assert.equal(resolveGridMode(settings, "3d", 12), "3d");
  assert.equal(resolveGridMode(settings, "3d", 48), "graticule");
  assert.equal(resolveGridMode({ ...settings, gridGraticuleEnabled: false }, "3d", 48), "hidden");
});

test("grid auto-disable and stable camera tile center are deterministic", () => {
  assert.equal(gridShouldBeVisible(settings, 9_999), true);
  assert.equal(gridShouldBeVisible(settings, 10_001), false);
  const first = snapGridCenter({ latitude: 55.7558, longitude: 37.6173 }, settings);
  const second = snapGridCenter({ latitude: 55.76, longitude: 37.62 }, settings);
  assert.deepEqual(first, second);
});

test("renderer swaps double-buffered data sources and never clears the live grid first", async () => {
  const source = await readFile(new URL("../apps/catalog/src/CesiumMapRenderer.tsx", import.meta.url), "utf8");
  assert.match(source, /class GridLayerController/);
  assert.match(source, /dataSourceDisplay\.ready/);
  assert.doesNotMatch(source, /function rebuildElevatedGrid[\s\S]*?entities\.removeAll\(\)/);
});