""" necroptimade landing page, rendered as a Jinja2 template. """

from pathlib import Path

from starlette.routing import Router, Route
from fastapi import Request
from fastapi.templating import Jinja2Templates

from optimade import __api_version__
from optimade.server.routers import ENTRY_COLLECTIONS
from optimade.server.routers.utils import meta_values, get_base_url
from optimade.server.config import CONFIG

template_dir = Path(__file__).parent.resolve()
TEMPLATES = Jinja2Templates(directory=[template_dir])


async def landing(request: Request):
    """Show a human-readable landing page when the base URL is accessed."""

    meta = meta_values(request.url, 1, 1, more_data_available=False)
    major_version = __api_version__.split(".")[0]
    versioned_url = f"{get_base_url(request.url)}/v{major_version}/"

    context = {
        "request": request,
        "request_url": request.url,
        "api_version": __api_version__,
        "implementation": meta.implementation,
        "versioned_url": versioned_url,
        "provider": meta.provider,
        "index_base_url": CONFIG.index_base_url,
        "endpoints": list(ENTRY_COLLECTIONS.keys()) + ["info"],
    }

    return TEMPLATES.TemplateResponse("landing_page.html", context)


router = Router(routes=[Route("/", endpoint=landing)])
