"use client";

import { useEffect, useState, type ReactNode } from "react";
import { onDocumentVisible } from "@/lib/visibilityReconcile";

/** 事件类型中文标签 */
export function kindLabel(kind: string): string {
  switch (kind) {
    case "pageview":
      return "浏览";
    case "bot":
      return "爬虫";
    case "probe":
      return "探测";
    default:
      return kind || "-";
  }
}

/** 来源类别中文标签 */
export function refKindLabel(kind: string): string {
  switch (kind) {
    case "direct":
      return "直接访问";
    case "internal":
      return "站内";
    case "search":
      return "搜索引擎";
    case "social":
      return "社交";
    case "external":
      return "外部链接";
    default:
      return kind || "-";
  }
}

export function deviceLabel(d: string): string {
  switch (d) {
    case "computer":
      return "电脑";
    case "mobile":
      return "手机";
    case "tablet":
      return "平板";
    default:
      return d || "未知";
  }
}

export function formatBytes(n: number): string {
  if (!Number.isFinite(n) || n <= 0) return "0 B";
  const units = ["B", "KB", "MB", "GB", "TB"];
  let v = n;
  let i = 0;
  while (v >= 1024 && i < units.length - 1) {
    v /= 1024;
    i++;
  }
  return `${v >= 100 ? Math.round(v) : v.toFixed(1)} ${units[i]}`;
}

export function formatInt(n: number): string {
  return new Intl.NumberFormat("zh-CN").format(n);
}

/** 简单加载/错误占位（居中卡片内文本） */
export function StatsState({ loading, error }: { loading?: boolean; error?: string }) {
  if (loading) {
    return (
      <div className="panel p-10 text-center text-[13px]" style={{ color: "var(--ink-3)" }}>
        正在加载…
      </div>
    );
  }
  if (error) {
    return (
      <div className="panel p-10 text-center text-[13px]" style={{ color: "var(--danger)" }}>
        {error}
      </div>
    );
  }
  return null;
}

export function TableEmpty({ text = "暂无数据" }: { text?: string }) {
  return (
    <p className="py-8 text-center text-[13px]" style={{ color: "var(--ink-3)" }}>
      {text}
    </p>
  );
}

/** 15 秒轮询 + 回前台即拉；返回手动 reload */
export function usePolling(load: () => void, intervalMs = 15_000) {
  const [, setTick] = useState(0);
  useEffect(() => {
    load();
    const timer = setInterval(load, intervalMs);
    const off = onDocumentVisible(load);
    return () => {
      clearInterval(timer);
      off();
    };
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [intervalMs]);
  return () => setTick((t) => t + 1);
}

/** 7/30 日区间切换段控件（各 Tab 复用） */
export function RangeSegmented({
  value,
  onChange,
}: {
  value: "7d" | "30d";
  onChange: (v: "7d" | "30d") => void;
}) {
  return (
    <div className="flex items-center gap-1.5" role="tablist" aria-label="统计区间">
      {(
        [
          { key: "7d", label: "近 7 日" },
          { key: "30d", label: "近 30 日" },
        ] as const
      ).map((o) => (
        <button
          key={o.key}
          type="button"
          role="tab"
          aria-selected={value === o.key}
          onClick={() => value !== o.key && onChange(o.key)}
          className="admin-seg"
        >
          {o.label}
        </button>
      ))}
    </div>
  );
}

export function CardShell({
  title,
  hint,
  actions,
  children,
}: {
  title: string;
  hint?: string;
  actions?: ReactNode;
  children: ReactNode;
}) {
  return (
    <div className="panel p-4 sm:p-5">
      <div className="flex items-start justify-between gap-2 mb-3">
        <div className="min-w-0">
          <h3 className="text-[14.5px] font-semibold" style={{ color: "var(--ink)" }}>
            {title}
          </h3>
          {hint ? <p className="meta text-[11.5px] mt-0.5">{hint}</p> : null}
        </div>
        {actions}
      </div>
      {children}
    </div>
  );
}