import type { Language } from "@/lib/i18n";
import type { Province } from "@/types/province";
import type { DistanceUnit, PrecipitationUnit, PressureUnit, TemperatureUnit, WindSpeedUnit } from "@/types/units";
import type { WeatherRegion } from "@/types/weather-region";

interface VapidKeyResponse {
  configured: boolean;
  publicKey: string | null;
}

export async function fetchVapidPublicKey(signal?: AbortSignal) {
  const response = await fetch("/api/notifications/vapid-key", { signal });
  if (!response.ok) throw new Error("Unable to load Web Push configuration.");
  return response.json() as Promise<VapidKeyResponse>;
}

interface SavePushSubscriptionOptions {
  region?: WeatherRegion;
  officialWarningsEnabled?: boolean;
  morningBriefEnabled?: boolean;
  tomorrowBriefEnabled?: boolean;
  latitude?: number | null;
  longitude?: number | null;
  locationName?: string | null;
  timezone?: string | null;
  countyTeryt?: string | null;
  temperatureUnit?: TemperatureUnit;
  windSpeedUnit?: WindSpeedUnit;
  precipitationUnit?: PrecipitationUnit;
  pressureUnit?: PressureUnit;
  distanceUnit?: DistanceUnit;
}

export async function savePushSubscription(
  subscription: PushSubscription,
  province: Province | null,
  language: Language,
  options: SavePushSubscriptionOptions = {},
) {
  const response = await fetch("/api/notifications/subscriptions", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({
      subscription: subscription.toJSON(),
      province,
      language,
      region: options.region ?? "PL",
      enabled: options.officialWarningsEnabled ?? true,
      morningBriefEnabled: options.morningBriefEnabled === true,
      tomorrowBriefEnabled: options.tomorrowBriefEnabled === true,
      latitude: options.latitude ?? null,
      longitude: options.longitude ?? null,
      locationName: options.locationName ?? null,
      timezone: options.timezone ?? null,
      countyTeryt: options.countyTeryt ?? null,
      temperatureUnit: options.temperatureUnit,
      windSpeedUnit: options.windSpeedUnit,
      precipitationUnit: options.precipitationUnit,
      pressureUnit: options.pressureUnit,
      distanceUnit: options.distanceUnit,
    }),
  });
  if (!response.ok) throw new Error("Unable to save push subscription.");
}

export async function deletePushSubscription(endpoint: string) {
  const response = await fetch("/api/notifications/subscriptions", {
    method: "DELETE",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ endpoint }),
  });
  if (!response.ok) throw new Error("Unable to delete push subscription.");
}

export async function sendTestPushNotification(endpoint: string) {
  const response = await fetch("/api/notifications/test", {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ endpoint }),
  });
  if (!response.ok) throw new Error("Unable to send test notification.");
}

export function decodeBase64UrlKey(value: string) {
  const padding = "=".repeat((4 - (value.length % 4)) % 4);
  const base64 = `${value}${padding}`.replace(/-/g, "+").replace(/_/g, "/");
  const raw = window.atob(base64);
  return Uint8Array.from(raw, (character) => character.charCodeAt(0));
}