export function fmtDur(ms: number): string {
  if (ms < 0) ms = 0;
  if (ms < 1000) return ms + "ms";
  const s = Math.floor(ms / 1000);
  if (s < 60) return s + "s";
  const m = Math.floor(s / 60), rs = s % 60;
  if (m < 60) return m + "m " + rs + "s";
  const h = Math.floor(m / 60), rm = m % 60;
  return h + "h " + rm + "m";
}

export function durClass(ms: number): string {
  if (ms > 10 * 60 * 1000) return "very-long";
  if (ms > 3 * 60 * 1000) return "long";
  return "";
}

export function fmtTime(ts: number | null): string {
  if (!ts) return "-";
  const d = new Date(ts), now = new Date();
  if (d.toDateString() === now.toDateString())
    return d.toLocaleTimeString("en-US", { hour: "2-digit", minute: "2-digit", second: "2-digit", hour12: false });
  return d.toLocaleDateString("en-US", { month: "short", day: "numeric" }) + " " +
    d.toLocaleTimeString("en-US", { hour: "2-digit", minute: "2-digit", hour12: false });
}

export function statusOf(t: { status: string }): "active" | "queued" | "completed" | "failed" {
  if (t.status === "processing") return "active";
  if (t.status === "queued") return "queued";
  if (t.status === "replied" || t.status === "no_reply" || t.status === "skipped") return "completed";
  return "failed";
}

export function typeClass(t: string): string {
  if (t.match(/^TOOL CALL/)) return "tool-call";
  if (t === "TOOL RESULT") return "tool-result";
  if (t === "TEXT") return "text";
  if (t.match(/^RESULT/)) return "result";
  if (t === "SESSION START") return "session";
  if (t === "USER") return "user";
  return "";
}

export function fmtSessTs(ts: string): string {
  const p = ts.match(/(\d{2}):(\d{2}):(\d{2})/);
  return p ? p[1] + ":" + p[2] + ":" + p[3] : ts;
}

export function formatTypeLabel(type: string): string {
  if (type.match(/^TOOL CALL/)) return "\u2192 " + type.replace(/^TOOL CALL:\s*/, "");
  if (type.match(/^RESULT/)) return "DONE";
  if (type === "SESSION START") return "START";
  return type;
}

export function truncate(s: string, max: number): string {
  return s.length > max ? s.slice(0, max - 3) + "..." : s;
}

const STALE_MS = 10 * 60 * 1000;

export function applyStale(t: { status: string; startedAt: number; processingAt?: number | null; detail: string }): void {
  const baseline = t.processingAt ?? t.startedAt;
  if (t.status === "processing" && (Date.now() - baseline) > STALE_MS) {
    t.status = "stalled";
    t.detail = t.detail || "no completion after " + fmtDur(Date.now() - baseline);
  }
}