import {
  composeShareImage,
  copyText,
  detectShareCapability,
  downloadShareImage,
  openShareSheet,
  shareFile,
  type ShareMetadata,
} from '../share';

export type ShareOutcome = 'shared' | 'downloaded' | 'copied' | 'dismissed' | 'failed';

export interface ShareRequest {
  image: string;
  filename: string;
  title: string;
  url?: string;
  merchantName?: string;
  productImage?: string;
}

export function tryOnFilename(productTitle?: string, at: number = Date.now()): string {
  const slug = productTitle
    ? productTitle.trim().toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-|-$/g, '')
    : '';
  return `virtual-tryon-${slug || 'result'}-${at}.png`;
}

function absoluteUrl(url: string): string {
  try { return new URL(url, window.location.href).href; } catch { return url; }
}

/** Gallery exports use the same branded compositor; the stored raw render is never handed off. */
export async function shareTryOn({ image, title, url, merchantName, productImage }: ShareRequest): Promise<ShareOutcome> {
  const productUrl = url ? absoluteUrl(url) : null;
  const metadata: ShareMetadata = { itemName: title, productUrl, brandName: merchantName, productImage };
  let blob: Blob;
  try {
    blob = await composeShareImage(image, metadata);
  } catch {
    return 'failed';
  }

  const file = shareFile(blob);
  const capability = detectShareCapability(file, navigator, metadata);
  if (capability === 'file_share') {
    const copyPromise = productUrl ? copyText(productUrl) : Promise.resolve(false);
    const resultPromise = openShareSheet(file, metadata);
    const [, result] = await Promise.all([copyPromise, resultPromise]);
    if (result.outcome === 'share_sheet_closed') return 'shared';
    if (result.outcome === 'cancelled') return 'dismissed';
  }

  try {
    downloadShareImage(blob);
    if (productUrl) void copyText(productUrl);
    return 'downloaded';
  } catch {
    if (productUrl && await copyText(productUrl)) return 'copied';
    return 'failed';
  }
}