// Status utilities for TimeToLeave
import type { ServerStatus, Event, Journey } from "./types";

export class StatusUtils {
  static async checkServerStatus(url: string): Promise<ServerStatus> {
    try {
      const res = await fetch(url, {
        method: "HEAD",
        signal: AbortSignal.timeout(5000),
      });
      return res.ok;
    } catch {
      return false;
    }
  }
}

/**
 * Derive a human-readable leave-by status from an event and its journeys.
 * Returns early / on-time / delayed / unknown based on the best journey's
 * real departure time relative to now.
 */
export function getLeaveStatus(event: Event, journeys: Journey[]): string {
  if (journeys.length === 0) {
    return "No journey data";
  }

  // Pick the earliest non-cancelled journey
  const best = journeys
    .filter((j) => !j.cancelled)
    .sort((a, b) => a.rD.getTime() - b.rD.getTime())[0];

  if (!best) {
    return "All journeys cancelled";
  }

  const diffMin = (best.rD.getTime() - Date.now()) / 60_000;

  if (diffMin < 0) {
    return "Departure missed";
  }
  if (best.delay > 10) {
    return `Delayed +${best.delay} min`;
  }
  if (diffMin <= 15) {
    return "Leave now";
  }
  return "On time";
}