export type Kind = "idle" | "working" | "verify" | "done" | "attention";

// Worker Job.state -> a literal, legible label + severity kind, collapsed to three
// honest phases: Searching -> Downloading -> Finishing. The record-label metaphor
// stays in the chrome; these labels never obscure what's happening.
const STATE_MAP: Record<string, { label: string; kind: Kind }> = {
  requested: { label: "Queued", kind: "idle" },
  matching: { label: "Searching", kind: "working" },
  matched: { label: "Searching", kind: "working" },
  downloading: { label: "Downloading", kind: "working" },
  tagging: { label: "Finishing", kind: "verify" },
  imported: { label: "Pressed", kind: "done" },
  needs_attention: { label: "Needs attention", kind: "attention" },
};

/** Compact elapsed label from an ISO/Date string to `now` (ms since epoch). */
export function timeAgo(value: string | Date | null | undefined, now: number): string {
  if (!value) return "";
  const t = new Date(value).getTime();
  if (Number.isNaN(t)) return "";
  const s = Math.max(0, Math.floor((now - t) / 1000));
  if (s < 60) return "just now";
  const m = Math.floor(s / 60);
  if (m < 60) return `${m}m`;
  const h = Math.floor(m / 60);
  if (h < 24) return `${h}h`;
  return `${Math.floor(h / 24)}d`;
}

/** Compact download ETA like "~4m left", "~45s left", "~1h 5m left". Null/≤0 → no label. */
export function etaLabel(seconds: number | null | undefined): string | null {
  if (seconds == null || seconds <= 0) return null;
  if (seconds < 60) return `~${seconds}s left`;
  const m = Math.round(seconds / 60);
  if (m < 60) return `~${m}m left`;
  const h = Math.floor(m / 60);
  return `~${h}h ${m % 60}m left`;
}

export function describeJob(state: string, stage: string): { label: string; kind: Kind } {
  void stage; // stage no longer drives the label; kept for call-site compatibility
  return (
    STATE_MAP[state] ?? {
      label: state ? state[0].toUpperCase() + state.slice(1) : "Unknown",
      kind: "idle",
    }
  );
}