"""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).
"""

import asyncio
import logging
from contextlib import asynccontextmanager
from collections.abc import AsyncIterator

from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from slowapi import _rate_limit_exceeded_handler
from slowapi.errors import RateLimitExceeded

from app.config import settings
from app.db.connection import connect, run_migrations
from app.rate_limit import limiter
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.calendar import router as calendar_router
from app.routers.day_overrides import router as day_overrides_router
from app.routers.fetch_data import router as fetch_data_router
from app.routers.fetch_data import scraper_router
from app.routers.leave_wishes import router as leave_wishes_router
from app.routers.plan import router as plan_router
from app.routers.planned_days import router as planned_days_router
from app.routers.settings import 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

logger = logging.getLogger(__name__)


def _configure_logging() -> None:
    level = logging.getLevelName(settings.log_level.upper())

    handler = logging.StreamHandler()
    handler.setLevel(level)
    handler.setFormatter(logging.Formatter("%(levelname)s %(name)s %(message)s"))

    app_logger = logging.getLogger("app")
    app_logger.handlers.clear()
    app_logger.addHandler(handler)
    app_logger.setLevel(level)
    app_logger.propagate = False
    app_logger.disabled = False

    for name, log in logging.Logger.manager.loggerDict.items():
        if (name == "app" or name.startswith("app.")) and isinstance(log, logging.Logger):
            log.disabled = False


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncIterator[None]:
    _configure_logging()

    if settings.database_type == "sqlite":
        try:
            await asyncio.to_thread(run_migrations, f"sqlite:///{settings.sqlite_path}")
        except Exception as exc:
            logger.error("Migration failed — DB schema may be incomplete: %s", exc, exc_info=True)

    # Re-enable after migrations: alembic's env.py calls fileConfig() which may
    # still touch logger state even with disable_existing_loggers=False.
    for name, log in logging.Logger.manager.loggerDict.items():
        if (name == "app" or name.startswith("app.")) and isinstance(log, logging.Logger):
            log.disabled = False

    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.middleware("http")
    async def log_error_responses(request: Request, call_next):
        response = await call_next(request)
        if response.status_code >= 400:
            logger.warning("%s %s %d", request.method, request.url.path, response.status_code)
        return response

    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(leave_wishes_router)
    app.include_router(plan_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.include_router(day_overrides_router)
    app.include_router(calendar_router)


app = create_app()


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