// src/app/sitemap.ts
// ─────────────────────────────────────────────────────────────────────────────
// Dynamic sitemap generated from Prisma data — emits one entry per locale per
// active page (home, applications, news articles, heritage, news hub).
//
// Auto-discoverable at /sitemap.xml, no Nginx config needed.
// Search engines re-crawl this on each visit; Next.js caches it for `revalidate`.
// ─────────────────────────────────────────────────────────────────────────────

import type { MetadataRoute } from "next";
import { prisma } from "@/lib/prisma";

const LOCALES = ["en", "it", "vec", "es", "de"] as const;

function baseUrl() {
  return (process.env.NEXT_PUBLIC_APP_URL || "https://rf-flux.com").replace(/\/$/, "");
}

export const revalidate = 3600; // Re-generate sitemap once per hour

export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
  const base = baseUrl();
  const now = new Date();

  const entries: MetadataRoute.Sitemap = [];

  // ── Static routes ─────────────────────────────────────────────
  const staticPaths = [
    { path: "", priority: 1.0, changeFrequency: "weekly" as const },
    { path: "/news", priority: 0.7, changeFrequency: "daily" as const },
    { path: "/heritage", priority: 0.6, changeFrequency: "monthly" as const },
    { path: "/team", priority: 0.6, changeFrequency: "monthly" as const },
    { path: "/privacy", priority: 0.3, changeFrequency: "yearly" as const },
  ];

  for (const locale of LOCALES) {
    for (const { path, priority, changeFrequency } of staticPaths) {
      entries.push({
        url: `${base}/${locale}${path}`,
        lastModified: now,
        changeFrequency,
        priority,
        alternates: {
          languages: Object.fromEntries(
            LOCALES.map((alt) => [alt, `${base}/${alt}${path}`])
          ),
        },
      });
    }
  }

  // ── Application pages ─────────────────────────────────────────
  try {
    const applications = await prisma.application.findMany({
      where: { isActive: true },
      select: { slug: true, updatedAt: true },
    });

    for (const app of applications) {
      for (const locale of LOCALES) {
        entries.push({
          url: `${base}/${locale}/applications/${app.slug}`,
          lastModified: app.updatedAt,
          changeFrequency: "weekly",
          priority: 0.9,
          alternates: {
            languages: Object.fromEntries(
              LOCALES.map((alt) => [alt, `${base}/${alt}/applications/${app.slug}`])
            ),
          },
        });
      }
    }
  } catch (error) {
    console.error("[sitemap] Failed to load applications:", error);
  }

  // ── News articles ─────────────────────────────────────────────
  try {
    const articles = await prisma.newsArticle.findMany({
      where: { isActive: true },
      select: { slug: true, updatedAt: true, publishedAt: true },
      orderBy: { publishedAt: "desc" },
    });

    for (const article of articles) {
      for (const locale of LOCALES) {
        entries.push({
          url: `${base}/${locale}/news/${article.slug}`,
          lastModified: article.updatedAt,
          changeFrequency: "monthly",
          priority: 0.7,
          alternates: {
            languages: Object.fromEntries(
              LOCALES.map((alt) => [alt, `${base}/${alt}/news/${article.slug}`])
            ),
          },
        });
      }
    }
  } catch (error) {
    console.error("[sitemap] Failed to load news articles:", error);
  }

  return entries;
}