const VALHALLA_BASE = process.env.VALHALLA_URL ?? "http://valhalla:8002";

export type ValhallaCosting = "pedestrian" | "bicycle" | "auto";

const COSTING_MAP: Record<string, ValhallaCosting> = {
  walking: "pedestrian",
  cycling: "bicycle",
  driving: "auto",
};

export interface IsochroneOpts {
  lng: number;
  lat: number;
  travelMode: string;
  contourMinutes: number[];
  polygons?: boolean;
}

export async function fetchIsochrone(opts: IsochroneOpts): Promise<object> {
  const costing = COSTING_MAP[opts.travelMode] ?? "pedestrian";
  const body = {
    locations: [{ lon: opts.lng, lat: opts.lat }],
    costing,
    contours: opts.contourMinutes.map((time) => ({ time })),
    polygons: opts.polygons ?? true,
    show_locations: false,
  };

  const res = await fetch(`${VALHALLA_BASE}/isochrone`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify(body),
    signal: AbortSignal.timeout(30_000),
  });

  if (!res.ok) {
    const text = await res.text();
    throw new Error(`Valhalla error ${res.status}: ${text}`);
  }

  return res.json();
}

export async function checkValhalla(): Promise<boolean> {
  try {
    const res = await fetch(`${VALHALLA_BASE}/status`, {
      signal: AbortSignal.timeout(3000),
    });
    return res.ok;
  } catch {
    return false;
  }
}