from contextlib import asynccontextmanager
from pathlib import Path

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

from . import db, version
from .api import fs, imports, libraries, requests, search


@asynccontextmanager
async def lifespan(app: FastAPI):
    db.init_db()
    yield


app = FastAPI(title="wordarr", lifespan=lifespan)

app.include_router(libraries.router)
app.include_router(search.router)
app.include_router(requests.router)
app.include_router(imports.router)
app.include_router(fs.router)


@app.get("/api/version")
def read_version():
    return {"version": version.VERSION, "build": version.BUILD,
            "built_at": version.BUILT_AT}


class RevalidatingStatics(StaticFiles):
    """Without a Cache-Control header the browser caches heuristically and does
    not ask again, so a redeployed app.js kept rendering the old UI. no-cache
    still allows the cached copy, it just has to be revalidated first - one 304
    per file per load."""

    def file_response(self, *args, **kwargs):  # starlette passes these positionally
        resp = super().file_response(*args, **kwargs)
        resp.headers["Cache-Control"] = "no-cache"
        return resp


static_dir = Path(__file__).parent.parent / "static"
app.mount("/", RevalidatingStatics(directory=static_dir, html=True), name="static")