/**
 * Generates an imgproxy URL for a given source image and options.
 *
 * Documentation: https://docs.imgproxy.net/usage/processing
 */

interface ImgproxyOptions {
  width?: number;
  height?: number;
  resizing_type?: 'fit' | 'fill' | 'fill-down' | 'force' | 'auto';
  gravity?: string;
  enlarge?: boolean;
  extension?: string;
}

/**
 * Encodes a string to Base64 (URL-safe)
 */
function encodeBase64(str: string): string {
  if (typeof Buffer !== 'undefined') {
    return Buffer.from(str)
      .toString('base64')
      .replace(/\+/g, '-')
      .replace(/\//g, '_')
      .replace(/=+$/, '');
  } else {
    // Fallback for browser environment if Buffer is not available
    return window.btoa(str).replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '');
  }
}

export function getImgproxyUrl(src: string, options: ImgproxyOptions = {}): string {
  const baseUrl = process.env.NEXT_PUBLIC_IMGPROXY_URL || 'https://img.infra.mintel.me';

  // If no imgproxy URL is configured, return the source as is
  if (!baseUrl) return src;

  // Handle local paths or relative URLs
  let absoluteSrc = src;
  if (src.startsWith('/')) {
    const baseUrlForSrc =
      process.env.NEXT_PUBLIC_BASE_URL ||
      (typeof window !== 'undefined' ? window.location.origin : 'https://klz-cables.com');
    if (baseUrlForSrc) {
      absoluteSrc = `${baseUrlForSrc.replace(/\/$/, '')}${src}`;
    }
  }

  // Development mapping: Map local domains to internal Docker hostnames
  // so imgproxy can fetch images without SSL issues or external routing
  if (process.env.NODE_ENV === 'development') {
    if (absoluteSrc.includes('klz.localhost')) {
      absoluteSrc = absoluteSrc.replace(/^https?:\/\/klz\.localhost/, 'http://klz-app:3000');
    } else if (absoluteSrc.includes('cms.klz.localhost')) {
      absoluteSrc = absoluteSrc.replace(/^https?:\/\/cms\.klz\.localhost/, 'http://klz-cms:8055');
    }
    // Also handle direct container names if needed
  }

  const {
    width = 0,
    height = 0,
    resizing_type = 'fit',
    gravity = 'sm', // Default to smart gravity
    enlarge = false,
    extension = '',
  } = options;

  // Processing options
  // Format: /rs:<type>:<width>:<height>:<enlarge>/g:<gravity>
  const processingOptions = [
    `rs:${resizing_type}:${width}:${height}:${enlarge ? 1 : 0}`,
    `g:${gravity}`,
  ].join('/');

  // Using /unsafe/ for now as we don't handle signatures yet
  // Format: <base_url>/unsafe/<options>/<base64_url>
  const suffix = extension ? `@${extension}` : '';
  const encodedSrc = encodeBase64(absoluteSrc + suffix);

  return `${baseUrl}/unsafe/${processingOptions}/${encodedSrc}`;
}