package handlers

import (
	"fmt"
	"net/http"
	"strings"
	"time"
)

// RobotsTxt serves /robots.txt dynamically so the Sitemap URL reflects the
// configured base URL rather than a hard-coded placeholder.
func (a *App) RobotsTxt(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	w.Header().Set("Cache-Control", "public, max-age=86400")
	fmt.Fprintf(w, `User-agent: *
Allow: /

# Private routes — do not crawl
Disallow: /admin/
Disallow: /api/
Disallow: /app/
Disallow: /account/
Disallow: /d/*/f/*/download
Disallow: /d/*/zip
Disallow: /d/*/thumb/
Disallow: /d/*/scene/
Disallow: /d/*/archive/
Disallow: /d/*/og-image.jpg
Disallow: /d/*/unlock
Disallow: /d/*/manage/

Sitemap: %s/sitemap.xml
`, strings.TrimRight(siteBaseURL(r, a.cfg.BaseURL), "/"))
}

// SitemapXML serves a minimal /sitemap.xml containing only the public,
// indexable homepage. Box/file pages are noindex and deliberately excluded.
func (a *App) SitemapXML(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/xml; charset=utf-8")
	w.Header().Set("Cache-Control", "public, max-age=3600")
	baseURL := strings.TrimRight(siteBaseURL(r, a.cfg.BaseURL), "/")
	lastMod := time.Now().UTC().Format("2006-01-02")
	fmt.Fprintf(w, `<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>%s/</loc>
    <lastmod>%s</lastmod>
    <changefreq>weekly</changefreq>
    <priority>1.0</priority>
  </url>
</urlset>
`, baseURL, lastMod)
}

func siteBaseURL(r *http.Request, configured string) string {
	if configured != "" {
		return configured
	}
	return absoluteURL(r, "/")
}