// Node.js
import wasm_image_loader from '@saschazar/wasm-image-loader'

// Web Worker - see: https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope/importScripts
importScripts('wasm_image_loader.js')

// -------- Browser/Web Worker/Node.js code below --------

// Load an image into a buffer using the Fetch API
const buffer = fetch('some JPEG or PNG').then((res) => res.buffer())

// Initialize the WebAssembly Module
const imageLoaderModule = new Promise((resolve) => {
  const wasm = wasm_image_loader({
    onRuntimeInitialized() {
      // remove the 'then' property from wasm_image_loader,
      // otherwise Promise runs into an endless loop.
      const { then, ...other } = wasm
      // let Promise resolve with 'other' properties.
      resolve(other)
    }
  })
})

async function loadImage() {
  // store image buffer in Uint8Array
  const array = new Uint8Array(await buffer())
  const channels = 3 // 3 if RGB, 4 if Alpha channel is present (e.g. PNG)

  // let imageLoaderModule Promise resolve
  const { decode, dimensions, free, resize } = await imageLoaderModule

  const decoded = decode(array, array.length, channels)
  const { channels, height, width } = dimensions()
  const resized = resize(decoded, width, height, channels, 800, 600)
  console.log(resized) // logs the uncompressed 800x600 RGB Uint8Array

  // clean up memory, when loader is not needed anymore
  free()
}