import { getAllBlogs } from "@/content/blogs/blogs";
import { getSettings } from "@/content/settings/settings";
import type { APIRoute } from "astro";
import minifyXML from "minify-xml";

export const GET = (async () => {
    const settings = await getSettings();

    if (!settings.blog.enabled) {
        return new Response(null, {
            status: 204,
            statusText: "Not Found"
        });
    }

    const blogs = await getAllBlogs(settings);
    const blogCount = blogs.length;
    const perPage = settings.sitemap.perPage;
    const pages = Math.ceil(blogCount / perPage);

    let sitemaps: SitemapIndex[] = [];

    for (let i = 0; i < pages; i++) {
        const selectedBlogs = blogs.slice(
            ((Number(i + 1) - 1) * settings.sitemap.perPage),
            Number(i + 1) * settings.sitemap.perPage - 1
        );

        let dates = [
            settings.sitemap.lastModified,
            settings.blog.lastModified,
            settings.website.lastModified
        ];

        selectedBlogs.forEach((blog) => {
            dates.push(blog.lastModified);
        });

        const lastModified = dates.sort((a: Date, b: Date) => {
            return b.getTime() - a.getTime();
        });

        sitemaps.push({
            url: `/sitemap/blogs-${i + 1}.xml`,
            lastModified: lastModified[0]
        });
    }

    let sitemapContent = `
    <?xml version="1.0" encoding="UTF-8"?>
    <sitemapindex xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    ${sitemaps.map((item) => `
        <sitemap>
            <loc>${settings.website.domainName}${item.url}</loc>
            <lastmod>${item.lastModified.toISOString()}</lastmod>
        </sitemap>
    `).join('')}
    </sitemapindex>
    `;

    return new Response(minifyXML(sitemapContent), {
        status: 200,
        statusText: "OK",
        headers: {
            "Content-Type": "application/xml"
        }
    });
}) satisfies APIRoute;