import assert from "node:assert/strict";
import { mkdir, readFile, writeFile } from "node:fs/promises";
import { gunzipSync } from "node:zlib";
import sharp from "sharp";
import { renderSnapshot } from "../renderer/render.mjs";
import { assertTerrainImage } from "../renderer/image-validation.mjs";

// Exercise the product's rendering worker without launching a Minecraft server
// or driving the website. A cached real export can also be supplied as argv[2].
const output = ".cache/renderer-regression";
const snapshot = {
  bounds: { minX: -24, minZ: -24, maxX: 24, maxZ: 24 },
  coverage: [],
  blocks: [],
};
for (let x = -24; x < 24; x++) {
  for (let z = -24; z < 24; z++) {
    snapshot.blocks.push([x, 63, z, "minecraft:dirt"]);
    snapshot.blocks.push([
      x,
      64,
      z,
      x > 12 && z < -12
        ? "minecraft:water[level=0]"
        : "minecraft:grass_block[snowy=false]",
    ]);
  }
}
for (let x = -4; x <= 4; x++) {
  for (let z = -4; z <= 4; z++) {
    for (let y = 65; y <= 71; y++) {
      if (Math.abs(x) === 4 || Math.abs(z) === 4 || y === 71) {
        snapshot.blocks.push([
          x,
          y,
          z,
          y === 71 ? "minecraft:oak_planks" : "minecraft:stone_bricks",
        ]);
      }
    }
  }
}
for (let y = 65; y <= 70; y++)
  snapshot.blocks.push([-16, y, 0, "minecraft:oak_log[axis=y]"]);
for (let x = -18; x <= -14; x++) {
  for (let z = -2; z <= 2; z++) {
    snapshot.blocks.push([
      x,
      71,
      z,
      "minecraft:oak_leaves[distance=1,persistent=true,waterlogged=false]",
    ]);
  }
}
snapshot.blocks.push([
  5,
  65,
  0,
  "minecraft:oak_stairs[facing=east,half=bottom,shape=straight,waterlogged=false]",
]);
let terrain = snapshot;
let points = [
  [-12.5, 12.5],
  [12.5, 12.5],
  [12.5, -12.5],
  [-12.5, -12.5],
  [0.5, 18.5],
].map(([x, z], i) => ({ id: `p${i}`, x, y: 66.62, z }));
let source = "grass, dirt, water, tree and building regression fixture";
if (process.argv[2]) {
  const directory = process.argv[2];
  const manifest = JSON.parse(
    await readFile(`${directory}/manifest.json`, "utf8"),
  );
  terrain = JSON.parse(
    gunzipSync(await readFile(`${directory}/terrain.json.gz`)).toString(),
  );
  points = manifest.viewpoints;
  source = "cached Paper export (no server started)";
}
await mkdir(output, { recursive: true });
const report = await renderSnapshot(terrain, points, output, { size: 256 });
assert.ok(report.meshes > 0, "terrain must produce meshes");
assert.ok(report.emittedFaces > 0, "terrain must produce faces");
assert.ok(report.hiddenFaces > 0, "interior terrain faces must be culled");
assert.ok(report.geometryBytes > 0, "geometry must reach the renderer");
assert.equal(
  report.unsupported.some((s) =>
    /minecraft:(stone|dirt|grass_block|water)(\[|$)/.test(s),
  ),
  false,
);
await assertTerrainImage(await readFile(`${output}/map.webp`), "Surface map");
for (const point of points) {
  for (const face of ["px", "nx", "py", "ny", "pz", "nz"]) {
    const metadata = await sharp(
      await readFile(`${output}/${point.id}/${face}.webp`),
    ).metadata();
    assert.equal(metadata.format, "webp");
    assert.equal(metadata.width, 256);
    assert.equal(metadata.height, 256);
  }
  await assertTerrainImage(
    await readFile(`${output}/${point.id}/ny.webp`),
    `Panorama ${point.id}, downward face`,
  );
}

// The earlier renderer silently accepted this case with zero meshes and faces.
const missingModel = {
  ...snapshot,
  blocks: [[0, 64, 0, "minecraft:minegeo_missing_model"]],
};
await assert.rejects(
  renderSnapshot(missingModel, [points[0]], `${output}/missing-model`, {
    size: 256,
  }),
  /No terrain models could be rendered/,
);
await writeFile(
  `${output}/verification.json`,
  JSON.stringify(
    {
      source,
      ...report,
      checks: [
        "nonempty terrain",
        "valid WebP cubemap faces",
        "surface visible below every viewpoint",
        "missing model rejected",
      ],
    },
    null,
    2,
  ),
);
console.log(
  "Renderer regression passed:",
  JSON.stringify({ source, ...report }),
);