import { NextResponse } from "next/server";

const GEOCODING_URL = "https://geocoding-api.open-meteo.com/v1/search";

interface RawLocation {
  id?: number;
  name?: string;
  latitude?: number;
  longitude?: number;
  admin1?: string;
  admin2?: string;
}

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const query = searchParams.get("query")?.trim() ?? "";
  const language = searchParams.get("language") === "en" ? "en" : "pl";
  if (query.length < 2 || query.length > 80) return NextResponse.json([]);

  const params = new URLSearchParams({
    name: query,
    count: "8",
    language,
    format: "json",
    countryCode: "PL",
  });
  try {
    const response = await fetch(`${GEOCODING_URL}?${params}`, { next: { revalidate: 86400 } });
    if (!response.ok) return NextResponse.json({ error: "Location search is unavailable." }, { status: 502 });
    const data = await response.json() as { results?: RawLocation[] };
    const results = (data.results ?? []).flatMap((location) => {
      if (!location.id || !location.name || !Number.isFinite(location.latitude) || !Number.isFinite(location.longitude)) return [];
      return [{
        id: location.id,
        name: location.name,
        latitude: location.latitude as number,
        longitude: location.longitude as number,
        province: location.admin1 ?? null,
        district: location.admin2 ?? null,
      }];
    });
    return NextResponse.json(results, { headers: { "Cache-Control": "public, s-maxage=86400, stale-while-revalidate=604800" } });
  } catch {
    return NextResponse.json({ error: "Location search is unavailable." }, { status: 502 });
  }
}