from threading import Lock

from fastapi import FastAPI, HTTPException, Query
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles

from .config import get_settings
from .schemas import ObjectSearchRequest, TrailRequest
from .services import AfterimageService


settings = get_settings()
_service_lock = Lock()
_service_instance: AfterimageService | None = None
app = FastAPI(title="Afterimage API", version="0.1.0")
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.cors_origin_list,
    allow_credentials=False,
    allow_methods=["*"],
    allow_headers=["*"],
)
app.mount("/assets", StaticFiles(directory=settings.resolved_asset_root), name="assets")


def service() -> AfterimageService:
    global _service_instance
    if _service_instance is None:
        with _service_lock:
            if _service_instance is None:
                _service_instance = AfterimageService(settings)
    return _service_instance


def bad_request(exc: Exception) -> HTTPException:
    return HTTPException(status_code=400, detail=str(exc))


@app.get("/api/health")
def health():
    try:
        return service().health()
    except Exception as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.get("/api/scenarios")
def scenarios():
    try:
        return service().scenarios()
    except Exception as exc:
        raise HTTPException(status_code=503, detail=str(exc)) from exc


@app.get("/api/memories")
def memories(
    scenario: str = Query(default="vault", max_length=60),
    zone: str | None = Query(default=None),
    region_id: str | None = Query(default=None),
    is_baseline: bool | None = Query(default=None),
):
    try:
        return service().memories(scenario=scenario, zone=zone, region_id=region_id, is_baseline=is_baseline)
    except ValueError as exc:
        raise bad_request(exc) from exc


@app.post("/api/anomaly/scan")
def anomaly_scan(scenario: str = Query(default="vault", max_length=60)):
    try:
        return service().scan_anomalies(scenario=scenario)
    except (FileNotFoundError, ValueError) as exc:
        raise bad_request(exc) from exc


@app.post("/api/object/search")
def object_search(request: ObjectSearchRequest):
    try:
        return service().object_search(
            scenario=request.scenario,
            asset_id=request.asset_id or request.crop_id,
            image_ref=request.image_ref,
            filters=request.filters,
            limit=request.limit,
        )
    except (FileNotFoundError, ValueError) as exc:
        raise bad_request(exc) from exc


@app.post("/api/trail")
def trail(request: TrailRequest):
    try:
        return service().trail(
            scenario=request.scenario,
            asset_id=request.asset_id or request.crop_id,
            image_ref=request.image_ref,
            score_cutoff=request.score_cutoff,
        )
    except (FileNotFoundError, ValueError) as exc:
        raise bad_request(exc) from exc


@app.get("/api/outliers")
def outliers(scenario: str = Query(default="vault", max_length=60)):
    try:
        return service().outliers(scenario=scenario)
    except ValueError as exc:
        raise bad_request(exc) from exc


@app.get("/api/matrix")
def matrix(scenario: str = Query(default="vault", max_length=60), sample: int = Query(default=24, ge=1, le=100)):
    try:
        return service().matrix(scenario=scenario, sample=sample)
    except ValueError as exc:
        raise bad_request(exc) from exc


@app.get("/api/text_search")
def text_search(q: str = Query(..., max_length=120), scenario: str | None = Query(default=None, max_length=60)):
    try:
        return service().text_search(query=q, scenario=scenario)
    except (FileNotFoundError, ValueError) as exc:
        raise bad_request(exc) from exc