"""FastAPI application factory."""

import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI

from gps_denied import __version__
from gps_denied.api.routers import flights
from gps_denied.config import RuntimeConfig
from gps_denied.pipeline import build_pipeline

logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Initialise core pipeline components on startup via build_pipeline."""
    cfg = RuntimeConfig()
    processor = build_pipeline(env=cfg.env, config=cfg)

    # Retrieve MAVLink bridge from processor internals for lifecycle management
    mavlink = processor._mavlink

    app.state.processor = processor
    app.state.config = cfg
    # Keep backwards-compat key so any code reading pipeline_components still works
    app.state.pipeline_components = {
        "vo": processor._vo,
        "gpr": processor._gpr,
        "metric": processor._metric,
        "graph": processor._graph,
        "recovery": processor._recovery,
        "chunk_mgr": processor._chunk_mgr,
        "rotation": processor._rotation,
        "coord": processor._coord,
        "satellite": processor._satellite,
        "mavlink": mavlink,
    }
    app.state.eskf_config = processor._eskf_config

    logger.info(
        "Pipeline ready — env=%s, MAVLink: %s, tiles: %s",
        cfg.env, cfg.mavlink.connection, cfg.satellite.tile_dir,
    )
    yield

    # Cleanup MAVLink on shutdown
    if mavlink is not None:
        try:
            await mavlink.stop()
        except Exception:
            pass
    app.state.pipeline_components = None


def create_app() -> FastAPI:
    """Factory function to create and configure the FastAPI application."""
    app = FastAPI(
        title="GPS-Denied Onboard API",
        description="REST API for UAV Flight Processing in GPS-denied environments.",
        version=__version__,
        lifespan=lifespan,
    )

    app.include_router(flights.router)

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

    return app


app = create_app()