"""temper_overview — the Temper-Linie live-overview page-module for the SPRO gateway.

This repository is a **gateway page-module**, not a standalone server. It is
mounted into the SPRO Universal Gateway as a git submodule at
``<gateway>/modules/temper_overview/`` and discovered automatically by the kernel
module loader (``app.core.modules.load_modules``), which imports this package and
calls ``register(app)`` after the core routers are mounted.

It does two things:

* mounts the built Vue SPA (``dist/``) as static files under ``/module/temper_overview``;
* exposes a small **read-only, no-auth** JSON API under ``/module/temper_overview/api``
  for the page to call (same origin → no CORS, no token).

The data is non-sensitive shop-floor data, so — like the kernel's ``/health`` and
``/heartbeat`` — the page API is deliberately unauthenticated. This is a per-page,
purpose-built read surface: never expose the generic ``POST /query/mariadb`` proxy
to the browser.

See ``agent_docs/vue-page-modules.md`` in the gateway repo for the full runbook,
and this repo's ``README.md`` for the design + build/deploy notes.
"""
from __future__ import annotations

from pathlib import Path

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

MODULE_NAME = "temper_overview"
# MUST match vite.config.ts `base` (with a trailing slash on the Vite side).
MODULE_PREFIX = "/module/temper_overview"

# CORS opt-in (read by the kernel loader, app.core.modules). This login-free board
# is embedded cross-origin in a Grafana text panel, which renders it inside a
# SANDBOXED iframe → the document gets an opaque origin (Origin: null). Vite tags the
# SPA's own JS/CSS `crossorigin`, so those assets are fetched in CORS mode and the
# browser blocks them (blank page) unless the gateway allows the read. "*" is safe:
# this is no-auth, read-only shop-floor data, and only "*" satisfies Origin: null.
CORS_ALLOW_ORIGINS = ["*"]


def register(app: FastAPI) -> None:
    """Mount the data API and the SPA onto the gateway app.

    Called once by the kernel loader during app construction. Order matters: a
    ``StaticFiles`` mount captures every path under its prefix, so the ``/api``
    routes are registered FIRST or the mount would shadow them.
    """
    # 1) Data API first (imported lazily so package import stays cheap).
    from .api import routes

    app.include_router(routes.router)

    # 2) Then the SPA. html=True serves dist/index.html at the prefix root.
    #    dist/ MUST exist (it is committed) — if it is missing this raises and the
    #    loader logs-and-skips the module (the kernel stays up but the page 404s).
    dist = Path(__file__).resolve().parent / "dist"
    app.mount(MODULE_PREFIX, StaticFiles(directory=dist, html=True), name=MODULE_NAME)