"""FastAPI application — entry point for the API server."""

from __future__ import annotations

import logging
from contextlib import asynccontextmanager

import httpx
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from nsct.config import AppSettings

logger = logging.getLogger(__name__)


# ---------------------------------------------------------------------------
# Lifespan
# ---------------------------------------------------------------------------


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan — startup and shutdown hooks."""
    config: AppSettings = app.state.config

    logger.info("NSCT API starting up — version %s", app.state.version)

    # Pre-flight: validate LLM connectivity
    llm_base = config.llm.base_url if config and config.llm and config.llm.base_url else ""
    if llm_base:
        try:
            async with httpx.AsyncClient(timeout=5.0) as client:
                resp = await client.get(f"{llm_base}/models")
                if resp.status_code == 200:
                    logger.info("LLM provider reachable — model endpoint returned 200")
                else:
                    logger.warning("LLM provider returned %s", resp.status_code)
        except Exception as exc:
            logger.warning("LLM connectivity check failed: %s", exc)

    yield


# ---------------------------------------------------------------------------
# App factory
# ---------------------------------------------------------------------------


def create_app() -> FastAPI:
    """Create the FastAPI application with all routes and middleware."""
    config = AppSettings.from_env()

    app = FastAPI(
        title="NSCT API",
        description="Neutral Search Crawler Tool — API server",
        version="0.1.0",
        docs_url="/docs" if config.debug else None,
        redoc_url="/redoc" if config.debug else None,
        lifespan=lifespan,
    )
    app.state.config = config
    app.state.version = "0.1.0"

    # CORS — allow local development
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["http://localhost:3000", "http://localhost:5173", "http://127.0.0.1:3000"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # Mount health router
    from nsct.api.health import router as health_router
    app.include_router(health_router, tags=["system"])

    # Mount search router
    from nsct.api.search import router as search_router
    app.include_router(search_router, tags=["search"])

    # Mount crawler router
    from nsct.api.crawler import router as crawler_router
    app.include_router(crawler_router, tags=["crawler"])

    # Mount planner router
    from nsct.api.planner import router as planner_router
    app.include_router(planner_router, tags=["planner"])

    # Mount claim extraction router (Stage 5)
    from nsct.api.claims import router as claims_router
    app.include_router(claims_router, tags=["research"])

    # Mount claim clustering router (Stage 7)
    from nsct.api.stage7 import router as stage7_router
    app.include_router(stage7_router, tags=["research"])

    # Mount evidence scoring router (Stage 8)
    from nsct.api.stage8 import router as stage8_router
    app.include_router(stage8_router, tags=["research"])

    # Mount synthesis router (Stage 9)
    from nsct.api.synthesis import router as synthesis_router
    app.include_router(synthesis_router, tags=["research"])

    # Mount vision router (Stage 10)
    from nsct.api.vision import router as vision_router
    app.include_router(vision_router, tags=["vision"])

    # Mount audio router (Stage 11)
    from nsct.api.audio import router as audio_router
    app.include_router(audio_router, tags=["audio"])

    # Mount REST API router (Stage 14)
    from nsct.api.rest_research import router as rest_research_router
    app.include_router(rest_research_router, tags=["research"])

    return app


app = create_app()