/**
 * Baseline A: WmlComparer via Docxodus WASM.
 *
 * Uses the Docxodus npm package's WASM-based comparison in Node.js.
 *
 * Note: WASM support in Node.js requires additional setup:
 * 1. WASM files must be served or loaded from the filesystem
 * 2. May need polyfills for browser APIs used by Blazor WASM
 *
 * This implementation is a placeholder - full WASM integration requires
 * building Docxodus and hosting the WASM files.
 */

import type { CompareResult } from '../../index.js';

export interface WasmOptions {
  /** Author name for revisions. Default: "Comparison" */
  author?: string;
  /** Detail threshold (0.0-1.0, lower = more detailed). Default: 0.15 */
  detailThreshold?: number;
  /** Case-insensitive comparison. Default: false */
  caseInsensitive?: boolean;
  /** Path to WASM files directory. */
  wasmPath?: string;
}

/** Whether WASM runtime has been initialized */
let wasmInitialized = false;

/**
 * Initialize the WASM runtime.
 *
 * Must be called before using compareWithWasm().
 *
 * @param wasmPath - Path to the directory containing WASM files
 */
export async function initializeWasm(wasmPath: string): Promise<void> {
  // TODO: Implement WASM initialization
  // This requires:
  // 1. Loading the Docxodus WASM module
  // 2. Initializing the .NET runtime
  // 3. Setting up any required polyfills for Node.js

  throw new Error(
    `WASM initialization not yet implemented. ` +
      `WASM path: ${wasmPath}. ` +
      `For now, use compareWithDotnet() as a fallback.`
  );
}

/**
 * Check if WASM runtime is initialized.
 */
export function isWasmInitialized(): boolean {
  return wasmInitialized;
}

/**
 * Compare two DOCX documents using WASM.
 *
 * @param original - Original document as Buffer
 * @param revised - Revised document as Buffer
 * @param options - WASM options
 * @returns Comparison result with track changes
 */
export async function compareWithWasm(
  original: Buffer,
  revised: Buffer,
  options: WasmOptions = {}
): Promise<CompareResult> {
  if (!wasmInitialized) {
    throw new Error(
      'WASM runtime not initialized. Call initializeWasm() first, ' +
        'or use compareWithDotnet() as a fallback.'
    );
  }

  const {
    author = 'Comparison',
    detailThreshold = 0.15,
    caseInsensitive = false,
  } = options;

  // TODO: Implement WASM-based comparison
  // This would call into the Docxodus WASM module:
  //
  // const docxodus = await import('docxodus');
  // const result = await docxodus.compareDocuments(
  //   new Uint8Array(original),
  //   new Uint8Array(revised),
  //   { authorName: author, detailThreshold, caseInsensitive }
  // );

  throw new Error(
    `WASM comparison not yet implemented. ` +
      `Options: author=${author}, detailThreshold=${detailThreshold}, caseInsensitive=${caseInsensitive}. ` +
      `Original size: ${original.length}, Revised size: ${revised.length}. ` +
      `Use compareWithDotnet() as a fallback.`
  );
}

/**
 * Check if WASM is available and can be used in this environment.
 *
 * Note: WASM in Node.js has limitations compared to browser environments.
 */
export async function isWasmAvailable(): Promise<boolean> {
  // Check for WebAssembly support
  // WebAssembly is available in Node.js since v8
  try {
    // Simple check that WebAssembly is available
    const testModule = new WebAssembly.Module(
      new Uint8Array([0x00, 0x61, 0x73, 0x6d, 0x01, 0x00, 0x00, 0x00])
    );
    return testModule !== null;
  } catch {
    return false;
  }
}
