import { prisma } from "@/lib/prisma";
import { locales } from "@/i18n/locales";
import { getBaseUrl } from "@/lib/seo";

export type SitemapEntry = {
  url: string;
  lastModified: string;
  changefreq?: "daily" | "weekly" | "monthly" | "yearly";
  priority?: number;
};

export function generateSitemapXml(entries: SitemapEntry[]): string {
  const xmlHeader = '<?xml version="1.0" encoding="UTF-8"?>';
  const urlsetOpen = '<urlset xmlns="https://www.sitemaps.org/schemas/sitemap/0.9">';
  const urlsetClose = "</urlset>";

  const urlEntries = entries
    .map((e) => {
      const changefreq = e.changefreq ?? "monthly";
      const priority = typeof e.priority === "number" ? e.priority : 0.8;
      return `
    <url>
      <loc>${e.url}</loc>
      <lastmod>${e.lastModified}</lastmod>
      <changefreq>${changefreq}</changefreq>
      <priority>${priority.toFixed(1)}</priority>
    </url>`;
    })
    .join("");

  return `${xmlHeader}${urlsetOpen}${urlEntries}${urlsetClose}`;
}

export async function getSitemapEntries(): Promise<SitemapEntry[]> {
  const baseUrl = getBaseUrl();
  const nowIso = new Date().toISOString();

  const staticPaths = ["", "/projects", "/legal-notice", "/privacy-policy"];
  const staticEntries: SitemapEntry[] = locales.flatMap((locale) =>
    staticPaths.map((p) => {
      const path = p === "" ? `/${locale}` : `/${locale}${p}`;
      return {
        url: `${baseUrl}${path}`,
        lastModified: nowIso,
        changefreq: p === "" ? "weekly" : p === "/projects" ? "weekly" : "yearly",
        priority: p === "" ? 1.0 : p === "/projects" ? 0.8 : 0.5,
      };
    }),
  );

  // Projects: for each project slug we publish per locale (same slug)
  const projects = await prisma.project.findMany({
    where: { published: true },
    select: { slug: true, updatedAt: true },
    orderBy: { updatedAt: "desc" },
  });

  const projectEntries: SitemapEntry[] = projects.flatMap((p) => {
    const lastModified = (p.updatedAt ?? new Date()).toISOString();
    return locales.map((locale) => ({
      url: `${baseUrl}/${locale}/projects/${p.slug}`,
      lastModified,
      changefreq: "monthly",
      priority: 0.7,
    }));
  });

  return [...staticEntries, ...projectEntries];
}