"""
ABOS AI Worker – FastAPI Application Entry Point
==================================================
Constructs and configures the FastAPI application:
  - Registers the CORS middleware (frontend-facing endpoints need this).
  - Mounts the API router.
  - Starts a periodic background task to evict expired documents.
  - Exposes /health and /info meta-endpoints.
"""

from __future__ import annotations

import asyncio
import logging
import logging.config

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

from app.config import settings
from app.routes import router
from app.email_analyzer import email_router
from app.meeting_analyzer import meeting_router
from app.project_ai import project_ai_router
from app.project_plan import project_plan_router
from app.store import document_store



# ---------------------------------------------------------------------------
# Logging setup
# ---------------------------------------------------------------------------
logging.basicConfig(
    level=logging.DEBUG if settings.debug else logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s – %(message)s",
    datefmt="%Y-%m-%dT%H:%M:%S",
)
logger = logging.getLogger(__name__)


# ---------------------------------------------------------------------------
# Periodic store cleanup
# ---------------------------------------------------------------------------

async def _periodic_store_cleanup(interval_seconds: int = 300) -> None:
    """Background coroutine that purges expired documents every *interval_seconds*."""
    while True:
        await asyncio.sleep(interval_seconds)
        try:
            purged = await document_store.purge_expired()
            if purged:
                logger.info("Store cleanup: purged %d expired document(s).", purged)
        except Exception as exc:  # noqa: BLE001
            logger.error("Store cleanup failed: %s", exc)


# ---------------------------------------------------------------------------
# Lifespan (replaces deprecated @app.on_event)
# ---------------------------------------------------------------------------

from contextlib import asynccontextmanager  # noqa: E402 (after stdlib imports)


@asynccontextmanager
async def lifespan(app: FastAPI):  # type: ignore[type-arg]
    """Start background cleanup task on startup; cancel it on shutdown."""
    cleanup_task = asyncio.create_task(_periodic_store_cleanup(interval_seconds=300))
    logger.info(
        "🚀  %s v%s starting up…", settings.app_name, settings.app_version
    )
    try:
        yield
    finally:
        cleanup_task.cancel()
        try:
            await cleanup_task
        except asyncio.CancelledError:
            pass
        logger.info("🛑  %s shut down cleanly.", settings.app_name)


# ---------------------------------------------------------------------------
# Application factory
# ---------------------------------------------------------------------------

app = FastAPI(
    title=settings.app_name,
    version=settings.app_version,
    description=(
        "Stateless AI Worker microservice for the ABOS Micro ERP platform. "
        "Handles PDF ingestion, LLM-based data extraction via OpenRouter, "
        "Human-in-the-Loop verification, and outbound webhook delivery to "
        "the Spring Boot backend."
    ),
    docs_url="/docs",
    redoc_url="/redoc",
    lifespan=lifespan,
)

# ---------------------------------------------------------------------------
# CORS Middleware
# ---------------------------------------------------------------------------
# Allow the React frontend to call the frontend-facing endpoints.
# In production, replace cors_origins in config.py / .env with the
# exact origin of your deployed React app.
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origins,
    allow_credentials=True,
    allow_methods=["GET", "POST", "OPTIONS"],
    allow_headers=["*"],
)

# ---------------------------------------------------------------------------
# Mount API routers
# ---------------------------------------------------------------------------
app.include_router(router, prefix="")
app.include_router(email_router, prefix="")
app.include_router(meeting_router, prefix="")
app.include_router(project_ai_router, prefix="")
app.include_router(project_plan_router, prefix="")