nezha-dash-v1/src/components/ServerFlag.tsx

import { cn } from "@/lib/utils";
import getUnicodeFlagIcon from "country-flag-icons/unicode";
import { useEffect, useState } from "react";

export default function ServerFlag({
  country_code,
  className,
}: {
  country_code: string;
  className?: string;
}) {
  const [supportsEmojiFlags, setSupportsEmojiFlags] = useState(false);


  useEffect(() => {
    const checkEmojiSupport = () => {
      const canvas = document.createElement("canvas");
      const ctx = canvas.getContext("2d");
      const emojiFlag = "🇺🇸"; // 使用美国国旗作为测试
      if (!ctx) return;
      ctx.fillStyle = "#000";
      ctx.textBaseline = "top";
      ctx.font = "32px Arial";
      ctx.fillText(emojiFlag, 0, 0);

      const support = ctx.getImageData(16, 16, 1, 1).data[3] !== 0;
      setSupportsEmojiFlags(support);
    };

    checkEmojiSupport();
  }, []);

  if (!country_code) return null;

  if (supportsEmojiFlags && country_code.toLowerCase() === "tw") {
    country_code = "cn";
  }

  return (
    <span className={cn("text-[12px] text-muted-foreground", className)}>
      { !supportsEmojiFlags ? (
        <span className={`fi fi-${country_code}`} />
      ) : (
        getUnicodeFlagIcon(country_code)
      )}
    </span>
  );
}