"""FastAPI application entrypoint.

Opens a database connection on startup, runs Alembic migrations, registers
routers, locks CORS to the configured frontend origin(s), and attaches a
rate-limiter to the app (applied per-endpoint via decorators).
"""

from contextlib import asynccontextmanager
from collections.abc import AsyncIterator

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from slowapi import Limiter, _rate_limit_exceeded_handler
from slowapi.errors import RateLimitExceeded
from slowapi.util import get_remote_address

from app.config import settings
from app.db.connection import connect, run_migrations
from app.routers import vacation_days
from app.routers.analytics import router as analytics_router
from app.routers.auth import router as auth_router
from app.routers.fetch_data import router as fetch_data_router
from app.routers.fetch_data import scraper_router
from app.routers.planned_days import router as planned_days_router
from app.routers.settings import break_router, child_router, settings_child_router, tips_router
from app.routers.workspace import _inv_router as invitations_router
from app.routers.workspace import router as workspace_router

limiter = Limiter(key_func=get_remote_address)


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncIterator[None]:
    # Run pending migrations before accepting requests (dev convenience).
    # In production, run `alembic upgrade head` as a separate deploy step.
    if settings.database_type == "sqlite":
        try:
            run_migrations(f"sqlite:///{settings.sqlite_path}")
        except Exception:
            pass  # migrations may fail in test envs without alembic installed

    app.state.db_connection = await connect(settings.sqlite_path)
    try:
        yield
    finally:
        await app.state.db_connection.close()


def create_app() -> FastAPI:
    app = FastAPI(title="Föräldraledigplannerare API", lifespan=lifespan)

    app.state.limiter = limiter
    app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)

    app.add_middleware(
        CORSMiddleware,
        allow_origins=list(settings.cors_origins),
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    _register_routers(app)
    return app


def _register_routers(app: FastAPI) -> None:
    app.include_router(auth_router)
    app.include_router(workspace_router)
    app.include_router(invitations_router)
    app.include_router(fetch_data_router)
    app.include_router(scraper_router)
    app.include_router(analytics_router)
    app.include_router(tips_router)
    app.include_router(break_router)
    app.include_router(child_router)
    app.include_router(settings_child_router)
    app.include_router(planned_days_router)
    app.include_router(vacation_days.router)


app = create_app()


@app.get("/health", tags=["health"])
async def health() -> dict[str, str]:
    return {"status": "ok"}