import assert from "node:assert/strict";
import fs from "node:fs";
import factory from "../../web/app/src/vendor/blender/web_engine.js";

const root = new URL("../../", import.meta.url);
const wasmBinary = fs.readFileSync(new URL("web/app/src/vendor/blender/web_engine.wasm", root));
const fixture = fs.readFileSync(new URL("tests/files/web/modifier_grease_pencil_scene.blend", root));

function open(engine, handle, bytes) {
  const pointer = engine._malloc(bytes.byteLength);
  try {
    engine.HEAPU8.set(bytes, pointer);
    assert.equal(engine._web_engine_open_blend(handle, pointer, bytes.byteLength), 0,
      engine.UTF8ToString(engine._web_engine_last_error_message()));
  }
  finally { engine._free(pointer); }
}

function output(engine, handle, fn, owned = false) {
  const dataOut = engine._malloc(4);
  const lengthOut = engine._malloc(4);
  try {
    assert.equal(fn(handle, dataOut, lengthOut), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
    const pointer = engine.HEAPU32[dataOut >>> 2];
    const length = engine.HEAPU32[lengthOut >>> 2];
    const bytes = engine.HEAPU8.slice(pointer, pointer + length);
    if (owned) engine._web_engine_free_buffer(pointer);
    return bytes;
  }
  finally {
    engine._free(dataOut);
    engine._free(lengthOut);
  }
}

function snapshot(engine, handle) {
  return JSON.parse(new TextDecoder().decode(output(engine, handle, engine._web_engine_get_scene_snapshot)));
}

function command(engine, handle, payload) {
  const bytes = new TextEncoder().encode(JSON.stringify(payload));
  const pointer = engine._malloc(bytes.byteLength);
  try {
    engine.HEAPU8.set(bytes, pointer);
    assert.equal(engine._web_engine_apply_command(handle, pointer, bytes.byteLength), 0,
      `${payload.type}: ${engine.UTF8ToString(engine._web_engine_last_error_message())}`);
  }
  finally { engine._free(pointer); }
}

function close(actual, expected, label) {
  assert.ok(Math.abs(actual - expected) <= 1e-6, `${label}: ${actual} != ${expected}`);
}

function assertFixture(scene) {
  const node = scene.nodes.find((candidate) => candidate.name === "GreasePencilObject");
  const data = scene.greasePencils?.find((candidate) => candidate.name === "GreasePencilData");
  assert.equal(node?.type, "GREASE_PENCIL");
  assert.equal(node?.dataId, data?.id);
  assert.equal(data?.geometryStatus, "available");
  assert.equal(data?.layerCount, 1);
  assert.equal(data?.frameCount, 1);
  assert.equal(data?.strokeCount, 1);
  assert.equal(data?.pointCount, 4);
  const layer = data.layers[0];
  const stroke = layer.frames[0].drawing.strokes[0];
  assert.equal(data.activeLayerId, layer.id);
  assert.equal(layer.name, "Lines");
  assert.equal(layer.visible, true);
  assert.equal(layer.locked, false);
  assert.equal(stroke.cyclic, false);
  assert.equal(stroke.materialIndex, 0);
  assert.equal(stroke.id, "grease-pencil-stroke:GreasePencilData:0:0");
  assert.deepEqual(stroke.points.map((point) => point.id), [
    "grease-pencil-point:GreasePencilData:0:0:0",
    "grease-pencil-point:GreasePencilData:0:0:1",
    "grease-pencil-point:GreasePencilData:0:0:2",
    "grease-pencil-point:GreasePencilData:0:0:3",
  ]);
  assert.deepEqual(stroke.points[0].position, [-1.5, 0, 0]);
  close(stroke.points[0].radius, 0.05, "radius");
  close(stroke.points[0].opacity, 0.9, "opacity");
  assert.equal(data.attributes.length, 6);
}

const engine = await factory({ wasmBinary: wasmBinary.slice() });
const handle = engine._web_engine_create();
open(engine, handle, fixture);
assertFixture(snapshot(engine, handle));
const original = snapshot(engine, handle).greasePencils[0];
const dataId = original.id;
command(engine, handle, { type: "createGreasePencilLayer", dataId, name: "Web Drafts" });
let edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.layerCount, 2);
const layerId = edited.layers.find((layer) => layer.name === "Web Drafts").id;
command(engine, handle, { type: "moveGreasePencilLayer", dataId, layerId, direction: "BOTTOM", baseRevision: edited.revision });
edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.layers[0].id, layerId);
assert.equal(engine._web_engine_undo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].layers[1].id, layerId);
assert.equal(engine._web_engine_redo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].layers[0].id, layerId);
command(engine, handle, { type: "insertGreasePencilFrame", dataId, layerId, frame: 10, duration: 4 });
const webStrokes = [{
  cyclic: true,
  materialIndex: 0,
  points: [
    { position: [0, 0, 0], radius: 0.1, opacity: 0.7, vertexColor: [1, 0, 0, 1] },
    { position: [1, 1, 0], radius: 0.2, opacity: 0.8, vertexColor: [0, 1, 0, 1] },
    { position: [2, 0, 0], radius: 0.3, opacity: 0.9, vertexColor: [0, 0, 1, 1] },
  ],
}];
command(engine, handle, { type: "setGreasePencilStrokes", dataId, layerId, frame: 10, strokes: webStrokes });
edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.frameCount, 2);
assert.equal(edited.strokeCount, 2);
assert.equal(edited.pointCount, 7);
assert.equal(edited.layers.find((layer) => layer.id === layerId).frames[0].drawing.strokes[0].cyclic, true);
assert.equal(engine._web_engine_undo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].strokeCount, 1);
assert.equal(engine._web_engine_redo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.pointCount, 7);
const sourceFrame = edited.layers.find((layer) => layer.id === layerId).frames[0];
command(engine, handle, { type: "moveGreasePencilFrame", dataId, layerId, frame: 10, targetFrame: 12, drawingId: sourceFrame.drawing.id, baseRevision: snapshot(engine, handle).revision });
edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.layers.find((layer) => layer.id === layerId).frames[0].frame, 12);
assert.equal(edited.layers.find((layer) => layer.id === layerId).frames[0].drawing.id, sourceFrame.drawing.id);
assert.equal(engine._web_engine_undo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].layers.find((layer) => layer.id === layerId).frames[0].frame, 10);
assert.equal(engine._web_engine_redo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].layers.find((layer) => layer.id === layerId).frames[0].frame, 12);
command(engine, handle, { type: "removeGreasePencilFrame", dataId, layerId, frame: 12 });
assert.equal(snapshot(engine, handle).greasePencils[0].frameCount, 1);
assert.equal(engine._web_engine_undo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
assert.equal(snapshot(engine, handle).greasePencils[0].frameCount, 2);
command(engine, handle, { type: "removeGreasePencilLayer", dataId, layerId });
assert.equal(snapshot(engine, handle).greasePencils[0].layerCount, 1);
assert.equal(engine._web_engine_undo(handle), 0, engine.UTF8ToString(engine._web_engine_last_error_message()));
edited = snapshot(engine, handle).greasePencils[0];
assert.equal(edited.layerCount, 2);
assert.equal(edited.pointCount, 7);
const saved = output(engine, handle, engine._web_engine_save_blend, true);
engine._web_engine_destroy(handle);

const reopened = engine._web_engine_create();
open(engine, reopened, saved);
const reopenedScene = snapshot(engine, reopened);
const reopenedData = reopenedScene.greasePencils[0];
assert.equal(reopenedData.layerCount, 2);
assert.equal(reopenedData.frameCount, 2);
assert.equal(reopenedData.strokeCount, 2);
assert.equal(reopenedData.pointCount, 7);
const reopenedStroke = reopenedData.layers.find((layer) => layer.name === "Web Drafts").frames[0].drawing.strokes[0];
assert.deepEqual(reopenedData.layers.map((layer) => layer.name), ["Web Drafts", "Lines"]);
assert.equal(reopenedData.layers.find((layer) => layer.name === "Web Drafts").frames[0].frame, 12);
assert.equal(reopenedData.layers.find((layer) => layer.name === "Web Drafts").frames[0].drawing.id, sourceFrame.drawing.id);
assert.equal(reopenedStroke.cyclic, true);
assert.deepEqual(reopenedStroke.points[2].position, [2, 0, 0]);
close(reopenedStroke.points[2].radius, 0.3, "reopened radius");
assert.deepEqual(
  reopenedData.layers.find((layer) => layer.name === "Lines").frames[0].drawing.strokes[0].points.map((point) => point.id),
  original.layers[0].frames[0].drawing.strokes[0].points.map((point) => point.id),
);
engine._web_engine_destroy(reopened);
process.stdout.write("grease-pencil-roundtrip-ok layer-frame-stroke=passed undo-redo=passed save-reopen=passed\n");