/**
 * What the four progress islands share besides the data: the not-ready body
 * (a skeleton while /api/stats loads, one muted line if it fails) and the
 * hover tooltip for the two charts drawn as plain SVG (the heatmap calendar
 * and the topic bubbles — Recharts has neither layout). The tooltip wears the
 * exact classes of shadcn's ChartTooltipContent, so all four cards' tooltips
 * look like one component.
 */
import { type PointerEvent, type ReactNode, useRef, useState } from "react";
import { cn } from "../../lib/utils";
import type { Load } from "../../lib/stats";
import { Skeleton } from "../ui/skeleton";

export function StatsPending({ load, className }: { load: Exclude<Load, { phase: "ready" }>; className: string }) {
  if (load.phase === "loading") return <Skeleton className={className} />;
  return (
    <p className="my-0! text-muted-foreground text-sm">
      Stats unavailable — they are served live from the SRS Worker, and it did not respond.
    </p>
  );
}

interface Tip {
  x: number;
  y: number;
  content: ReactNode;
}

/**
 * A pointer-following tooltip for SVG marks. Put `ref` on a `relative`
 * wrapper, call `show` from a mark's pointer events, render `tip` inside the
 * wrapper. Positions are relative to the wrapper, so page scroll never skews it.
 */
export function useHoverTip<T extends HTMLElement>() {
  const ref = useRef<T>(null);
  const [tip, setTip] = useState<Tip | null>(null);
  const show = (event: PointerEvent, content: ReactNode) => {
    const box = ref.current?.getBoundingClientRect();
    if (box) setTip({ x: event.clientX - box.left, y: event.clientY - box.top, content });
  };
  const hide = () => setTip(null);
  const node = tip && (
    <div
      className={cn(
        "pointer-events-none absolute z-10 grid min-w-[8rem] -translate-x-1/2 -translate-y-[calc(100%+0.75rem)] items-start gap-1.5",
        "rounded-lg border border-border/50 bg-background px-2.5 py-1.5 text-xs shadow-xl",
      )}
      style={{ left: tip.x, top: tip.y }}
    >
      {tip.content}
    </div>
  );
  return { ref, show, hide, node };
}

/** One tooltip row, the shape ChartTooltipContent draws: colour dot, label, mono value. */
export function TipRow({ color, label, value }: { color: string; label: ReactNode; value: ReactNode }) {
  return (
    <div className="flex w-full items-center gap-2">
      <div className="size-2.5 shrink-0 rounded-[2px]" style={{ background: color }} />
      <div className="flex flex-1 items-center justify-between gap-4 leading-none">
        <span className="text-muted-foreground">{label}</span>
        <span className="font-medium font-mono text-foreground tabular-nums">{value}</span>
      </div>
    </div>
  );
}