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

const fixtures = process.argv.slice(2);
const fixtureNames = fixtures.length > 0 ? fixtures : [
  "empty.blend",
  "basic_scene.blend",
  "rigged_shape_scene.blend",
];

function readFixture(name) {
  if (name.includes("/")) return fs.readFileSync(name);
  return fs.readFileSync(new URL(`../../tests/files/web/${name}`, import.meta.url));
}

function openBlend(engine, handle, bytes) {
  const pointer = engine._malloc(bytes.byteLength);
  try {
    engine.HEAPU8.set(bytes, pointer);
    return engine._web_engine_open_blend(handle, pointer, bytes.byteLength);
  }
  finally {
    engine._free(pointer);
  }
}

function evaluate(engine, handle) {
  const dataOut = engine._malloc(4);
  const lengthOut = engine._malloc(4);
  try {
    const result = engine._web_engine_evaluate_depsgraph(handle, dataOut, lengthOut);
    const messagePointer = engine._web_engine_last_error_message();
    const message = messagePointer ? engine.UTF8ToString(messagePointer) : "";
    if (result !== 0) return { result, message };
    const pointer = engine.HEAPU32[dataOut >>> 2];
    const length = engine.HEAPU32[lengthOut >>> 2];
    return { result, report: JSON.parse(new TextDecoder().decode(engine.HEAPU8.slice(pointer, pointer + length))) };
  }
  finally {
    engine._free(dataOut);
    engine._free(lengthOut);
  }
}

function snapshot(engine, handle) {
  const dataOut = engine._malloc(4);
  const lengthOut = engine._malloc(4);
  try {
    if (engine._web_engine_get_scene_snapshot(handle, dataOut, lengthOut) !== 0) return null;
    const pointer = engine.HEAPU32[dataOut >>> 2];
    const length = engine.HEAPU32[lengthOut >>> 2];
    return JSON.parse(new TextDecoder().decode(engine.HEAPU8.slice(pointer, pointer + length)));
  }
  finally {
    engine._free(dataOut);
    engine._free(lengthOut);
  }
}

for (const fixtureName of fixtureNames) {
  process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} stage=create\n`);
  try {
    const engine = await factory({ wasmBinary: fs.readFileSync(new URL("../../web/app/src/vendor/blender/web_engine.wasm", import.meta.url)) });
    const handle = engine._web_engine_create();
    process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} stage=open\n`);
    const openResult = openBlend(engine, handle, readFixture(fixtureName));
    if (openResult !== 0) {
      process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} open=${openResult} message=${engine.UTF8ToString(engine._web_engine_last_error_message())}\n`);
      engine._web_engine_destroy(handle);
      continue;
    }
    if (process.env.DIAGNOSE_SNAPSHOT === "1") {
      const scene = snapshot(engine, handle);
      process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} snapshot=${JSON.stringify(scene?.meshes?.map((mesh) => ({ id: mesh.id, modifiers: mesh.modifierStack })) ?? [])}\n`);
    }
    process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} stage=evaluate\n`);
    const evaluation = evaluate(engine, handle);
    process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} result=${JSON.stringify(evaluation)}\n`);
    engine._web_engine_destroy(handle);
  }
  catch (error) {
    const message = error instanceof Error ? error.message : String(error);
    process.stdout.write(`depsgraph-diagnostic fixture=${fixtureName} exception=${message}\n`);
    if (error instanceof Error && error.stack) {
      const wasmFrames = error.stack.split("\n")
        .filter((line) => line.includes("wasm-function") || line.trimStart().startsWith("at "))
        .filter((line) => !line.includes("web_engine.js:9"))
        .slice(0, 16);
      for (const frame of wasmFrames) process.stdout.write(`depsgraph-diagnostic stack=${frame.trim()}\n`);
    }
  }
}