import { WASI } from "@wasmer/wasi";
import { lowerI64Imports } from "@wasmer/wasm-transformer"

import { WasmFs } from "@wasmer/wasmfs";

// Instantiate a new WASI Instance
const wasmFs = new WasmFs();
let wasi = new WASI({
  args: [],
  env: {},
  bindings: {
    // uses browser APIs in the browser, node APIs in node
    ...WASI.defaultBindings,
    fs: wasmFs.fs
  }
});

const startWasiTask = async () => {
  // Fetch our Wasm File
  const response = await fetch("./my-wasi-module.wasm");
  const responseArrayBuffer = await response.arrayBuffer();

  // Instantiate the WebAssembly file
  const wasm_bytes = new Uint8Array(responseArrayBuffer).buffer;
  const lowered_wasm = await lowerI64Imports(wasm_bytes);
  let module = await WebAssembly.compile(lowered_wasm);
  let instance = await WebAssembly.instantiate(module, {
    ...wasi.getImports(module)
  });

  // Start the WebAssembly WASI instance!
  wasi.start(instance);

  // Output what's inside of /dev/stdout!
  const stdout = await wasmFs.getStdOut();
  console.log(stdout);
};
startWasiTask();