"""Sitemap & robots.txt generation: tenant-aware SEO content.

Because this is a white-label app where each tenant has its own domain
(set via KMTN_WEBSITE_URL), the sitemap and robots.txt are generated
at runtime — no static files are needed.  The FastAPI /api/sitemap/*
endpoints call these functions; Nginx proxies /sitemap.xml and
/robots.txt to those endpoints so search-engine crawlers hit the right
content at the root URL.
"""

# Public routes included in the sitemap with their change frequency and priority.
SEOMAP_ROUTES = [
    {"path": "/", "changefreq": "daily", "priority": 1.0},
    {"path": "/about", "changefreq": "weekly", "priority": 0.8},
    {"path": "/schedule", "changefreq": "weekly", "priority": 0.8},
    {"path": "/events", "changefreq": "daily", "priority": 0.8},
    {"path": "/contact", "changefreq": "monthly", "priority": 0.5},
]


def build_sitemap_xml(base_url: str) -> str:
    """Build a valid sitemap.xml string for the given base URL."""
    url = base_url.rstrip("/")
    entries = []
    for route in SEOMAP_ROUTES:
        entries.append(
            f"  <url>\n"
            f"    <loc>{url}{route['path']}</loc>\n"
            f"    <changefreq>{route['changefreq']}</changefreq>\n"
            f"    <priority>{route['priority']}</priority>\n"
            f"  </url>"
        )
    return (
        '<?xml version="1.0" encoding="UTF-8"?>\n'
        '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n'
        + "\n".join(entries) + "\n"
        "</urlset>\n"
    )


def build_robots_txt(base_url: str) -> str:
    """Build a robots.txt string that references the correct sitemap URL."""
    sitemap = base_url.rstrip("/") + "/sitemap.xml"
    return (
        "User-agent: *\n"
        "Allow: /\n"
        "\n"
        "Disallow: /admin\n"
        "Disallow: /login\n"
        "\n"
        f"Sitemap: {sitemap}\n"
    )