import { useEffect, useState } from "react";
import { cn } from "@/lib/utils";

export type ConnectionStatus =
  | "live"
  | "connecting"
  | "reconnecting"
  | "closed"
  | "stalled"
  | "error";

const STATUS_TONE: Record<
  ConnectionStatus,
  { dot: string; ring: string; label: string }
> = {
  live: {
    dot: "bg-[hsl(var(--success))]",
    ring: "ring-[hsl(var(--success))]/40",
    label: "Live",
  },
  connecting: {
    dot: "bg-[hsl(var(--signal))]",
    ring: "ring-[hsl(var(--signal))]/40",
    label: "Connecting",
  },
  reconnecting: {
    dot: "bg-[hsl(var(--signal))]",
    ring: "ring-[hsl(var(--signal))]/40",
    label: "Reconnecting",
  },
  closed: {
    dot: "bg-muted-foreground",
    ring: "ring-muted-foreground/30",
    label: "Closed",
  },
  stalled: {
    dot: "bg-destructive",
    ring: "ring-destructive/40",
    label: "Stalled",
  },
  error: {
    dot: "bg-destructive",
    ring: "ring-destructive/40",
    label: "Error",
  },
};

/**
 * Refined status pill with an animated dot. The dot pulses for any
 * non-terminal status and stays solid for stable states. Sits inline
 * with other header chrome and reads as a one-word status, not a
 * multi-line status panel.
 */
export function StatusPill({
  status,
  label,
  className,
}: {
  status: ConnectionStatus;
  label?: string;
  className?: string;
}) {
  const tone = STATUS_TONE[status];
  const isPulsing =
    status === "live" ||
    status === "connecting" ||
    status === "reconnecting";

  return (
    <span
      className={cn(
        "inline-flex items-center gap-1.5 rounded-full border border-border/60 bg-card/60 px-2.5 py-1 mono text-[10.5px] uppercase tracking-[0.14em]",
        className
      )}
    >
      <span
        className={cn(
          "relative inline-flex h-1.5 w-1.5 rounded-full",
          tone.dot,
          "ring-4",
          tone.ring
        )}
      >
        {isPulsing ? (
          <span
            className={cn(
              "absolute inline-flex h-full w-full rounded-full opacity-60 animate-ping",
              tone.dot
            )}
          />
        ) : null}
      </span>
      <span className="text-foreground/80">{label ?? tone.label}</span>
    </span>
  );
}

/**
 * Re-tick every second so a "Last event: 12s ago" subtitle stays
 * current without a parent re-render. Mount-once interval.
 */
export function useTickingNow(intervalMs = 1000): number {
  const [now, setNow] = useState<number>(() => Date.now());
  useEffect(() => {
    const id = setInterval(() => setNow(Date.now()), intervalMs);
    return () => clearInterval(id);
  }, [intervalMs]);
  return now;
}

export function formatAge(seconds: number): string {
  if (seconds < 0) return "0s";
  if (seconds < 60) return `${seconds}s`;
  const m = Math.floor(seconds / 60);
  const s = seconds % 60;
  if (m < 60) return s === 0 ? `${m}m` : `${m}m ${s}s`;
  const h = Math.floor(m / 60);
  return `${h}h ${m % 60}m`;
}