feat: add interactive daily forecast details

lib/forecast-utils.ts

@@ -1,5 +1,6 @@
 import type { Language, TranslationKey } from "@/lib/i18n";
 import { translate } from "@/lib/i18n";
+import type { HourlyForecast } from "@/types/forecast";
 
 export function getForecastConditionKey(code: number | null): TranslationKey {
   if (code === 0) return "forecast.condition.clear";
@@ -26,3 +27,38 @@ export function formatForecastRainfall(value: number | null, language: Language)
   if (value === null) return "—";
   return `${new Intl.NumberFormat(language === "pl" ? "pl-PL" : "en-GB", { maximumFractionDigits: 1 }).format(value)} mm`;
 }
+
+export function formatForecastWind(value: number | null, language: Language) {
+  if (value === null) return "—";
+  return `${new Intl.NumberFormat(language === "pl" ? "pl-PL" : "en-GB", {
+    minimumFractionDigits: 1,
+    maximumFractionDigits: 1,
+  }).format(value)} m/s`;
+}
+
+function getWarsawForecastHour(date = new Date()) {
+  const parts = new Intl.DateTimeFormat("en-CA", {
+    timeZone: "Europe/Warsaw",
+    year: "numeric",
+    month: "2-digit",
+    day: "2-digit",
+    hour: "2-digit",
+    hourCycle: "h23",
+  }).formatToParts(date);
+  const getPart = (type: Intl.DateTimeFormatPartTypes) => parts.find((part) => part.type === type)?.value ?? "";
+
+  return `${getPart("year")}-${getPart("month")}-${getPart("day")}T${getPart("hour")}:00`;
+}
+
+export function getUpcomingHourlyForecast(hours: HourlyForecast[], limit = 24) {
+  const currentHour = getWarsawForecastHour();
+  return hours.filter((hour) => hour.time >= currentHour).slice(0, limit);
+}
+
+export function getHourlyForecastForDay(hours: HourlyForecast[], date: string) {
+  return hours.filter((hour) => hour.time.startsWith(`${date}T`));
+}
+
+export function isForecastHourPast(time: string) {
+  return time < getWarsawForecastHour();
+}