import { NextResponse } from "next/server";
import { fetchServerCurrentWeather } from "@/lib/server-current-weather";
import type { WeatherRegion } from "@/types/weather-region";

function parseCoordinate(value: string | null, min: number, max: number) {
  if (!value?.trim()) return null;
  const coordinate = Number(value);
  return Number.isFinite(coordinate) && coordinate >= min && coordinate <= max ? coordinate : null;
}

function parseRegion(value: string | null): WeatherRegion {
  return value === "GLOBAL" ? "GLOBAL" : "PL";
}

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const latitude = parseCoordinate(searchParams.get("latitude"), -90, 90);
  const longitude = parseCoordinate(searchParams.get("longitude"), -180, 180);
  const region = parseRegion(searchParams.get("region"));
  if (latitude === null || longitude === null) {
    return NextResponse.json({ error: "Invalid coordinates." }, { status: 400 });
  }

  try {
    return NextResponse.json(await fetchServerCurrentWeather(latitude, longitude, region), {
      headers: { "Cache-Control": "public, s-maxage=120, stale-while-revalidate=300" },
    });
  } catch {
    return NextResponse.json({ error: region === "PL" ? "IMGW Hybrid service is unavailable." : "Open-Meteo current conditions are unavailable." }, { status: 502 });
  }
}