import { Metadata } from 'next';
import { SUPPORTED_LOCALES } from './locales';

const baseUrl = process.env.NEXT_PUBLIC_SITE_URL || 'http://localhost:3000';

type SeoMetadataProps = {
  title: string;
  description: string;
  path: string; // e.g. '/shop', '/category/1', or ''
  lang: string;
  openGraph?: Metadata['openGraph'];
};

export function generateSeoMetadata({
  title,
  description,
  path,
  lang,
  openGraph,
}: SeoMetadataProps): Metadata {
  const cleanPath = path.startsWith('/') ? path : `/${path}`;
  const pathPart = cleanPath === '/' ? '' : cleanPath;
  
  const languages: Record<string, string> = {};
  SUPPORTED_LOCALES.forEach((locale) => {
    languages[locale] = `${baseUrl}/${locale}${pathPart}`;
  });

  return {
    title,
    description,
    alternates: {
      canonical: `${baseUrl}/${lang}${pathPart}`,
      languages,
    },
    openGraph,
  };
}