// TypeScript wrapper for SVGit4Me: VTracer (color) and Potrace (B/W)
// Assumes vtracer_webapp.js, vtracer_webapp_bg.wasm, and vtracer_webapp.d.ts are in '../wasm/'

// No static import of vtracer glue code!

// Temporary module declaration for esm-potrace-wasm types
// Remove this when upstream types are compatible with your tsconfig
// @ts-ignore
declare module 'esm-potrace-wasm';

// Utility to convert a File/Blob to ArrayBuffer
async function fileToArrayBuffer(file: File | Blob): Promise<ArrayBuffer> {
  return await file.arrayBuffer();
}

export type SVGit4MeOptions = {
  color?: boolean; // true = color (VTracer), false = B/W (Potrace)
  color_mode?: 'color' | 'bw'; // alternative to color
  wasmPath?: string; // custom path to vtracer_webapp_bg.wasm
  potraceOptions?: any; // options for Potrace
  // VTracer and Potrace options can be passed through
  [key: string]: any;
};

/**
 * Convert PNG/JPG to SVG using VTracer (color) or Potrace (B/W)
 * @param image File, Blob, or ArrayBuffer
 * @param options SVGit4MeOptions (use 'wasmPath' to customize WASM location for VTracer)
 * @returns SVG string
 */
export async function convertToSVG(
  image: File | Blob | ArrayBuffer,
  options: SVGit4MeOptions = {}
): Promise<string> {
  // Decide which engine to use
  const useColor = options.color === true || options.color_mode === 'color';
  const useBW = options.color === false || options.color_mode === 'bw';

  // Convert input to ArrayBuffer if needed
  const buffer =
    image instanceof ArrayBuffer ? image : await fileToArrayBuffer(image);

  if (useBW) {
    // Use esm-potrace-wasm for B/W tracing
    // Dynamically import to ensure ESM compatibility
    const { trace } = await import('esm-potrace-wasm');
    // Potrace expects Uint8Array (image data)
    const uint8 = new Uint8Array(buffer);
    // Pass options.potraceOptions or options directly
    const svgString = await trace(uint8, options.potraceOptions || options);
    return svgString;
  } else {
    // Use VTracer for color (default)
    let vtracerInit: any;
    let ColorImageConverter: any;
    if (typeof window !== 'undefined' && (window as any).ColorImageConverter) {
      // Loaded globally (e.g. via <Script src="/vtracer_webapp.js" /> in Next.js)
      vtracerInit = (window as any).default || (window as any).vtracerInit;
      ColorImageConverter = (window as any).ColorImageConverter;
    } else {
      // Try dynamic import (ESM)
      const glue = await import('../wasm/vtracer_webapp.js');
      vtracerInit = glue.default;
      ColorImageConverter = glue.ColorImageConverter;
    }
    if (options.wasmPath) {
      await vtracerInit(options.wasmPath);
    } else {
      await vtracerInit();
    }
    // Create a hidden SVG element in the DOM
    const svgId = options.svg_id || `svgit4me-svg-${Math.random().toString(36).slice(2)}`;
    let svgElem = document.getElementById(svgId) as SVGSVGElement | null;
    if (!svgElem) {
      svgElem = document.createElementNS('http://www.w3.org/2000/svg', 'svg') as SVGSVGElement;
      svgElem.setAttribute('id', svgId);
      (svgElem as SVGSVGElement).style.display = 'none';
      document.body.appendChild(svgElem);
    }
    // Add svg_id to options for WASM
    options.svg_id = svgId;
    const params = JSON.stringify(options);
    const converter = ColorImageConverter.new_with_string(params);
    converter.init();
    while (converter.tick()) {}
    // Get the SVG string from the DOM
    let svgString = '';
    if (svgElem) {
      svgString = svgElem.outerHTML;
      converter.free();
      // Optionally remove the SVG element
      svgElem.remove();
    }
    return svgString;
  }
}