// country_code.dart — 节点地区图标(国旗,未知码回退码块) + 信号条
import 'package:country_flags/country_flags.dart';
import 'package:flutter/material.dart';
import '../pangolin_theme.dart';

/// 节点地区图标：有效 2 字母地区码渲染国旗(SVG,填满裁切,全平台含 Windows 都显示);
/// 未知码(AUTO / ·· / 空等)回退为原 2 字母码块。选中态加 accent 边框环。
class CountryCode extends StatelessWidget {
  const CountryCode({super.key, required this.code, this.active = false, this.size = 38});
  final String code;
  final bool active;
  final double size;

  @override
  Widget build(BuildContext context) {
    final c = context.pangolin;
    final radius = BorderRadius.circular(PangolinRadius.md);
    final hasFlag = FlagCode.fromCountryCode(code.toUpperCase()) != null;

    if (!hasFlag) {
      // 回退：原码块样式(AUTO / 占位 / 非地区码)。
      return Container(
        width: size,
        height: size,
        alignment: Alignment.center,
        decoration: BoxDecoration(
          color: active ? c.accent : c.bgSubtle,
          borderRadius: radius,
        ),
        child: Text(
          code,
          style: PangolinText.mono.copyWith(
            fontSize: size * 0.31,
            fontWeight: FontWeight.w600,
            color: active ? PangolinColors.white : c.fg2,
          ),
        ),
      );
    }

    // 国旗：外层 Container 控圆角 + 选中边框，内层 CountryFlag 以 BoxFit.cover 填满裁切。
    return Container(
      width: size,
      height: size,
      clipBehavior: Clip.antiAlias,
      decoration: BoxDecoration(
        borderRadius: radius,
        border: active ? Border.all(color: c.accent, width: 2) : null,
      ),
      child: CountryFlag.fromCountryCode(
        code.toUpperCase(),
        width: size,
        height: size,
      ),
    );
  }
}

/// 三格信号条,依据延迟 ping 显示强度。
class SignalBars extends StatelessWidget {
  const SignalBars({super.key, required this.ping});
  final int ping;

  @override
  Widget build(BuildContext context) {
    final c = context.pangolin;
    final level = ping < 40 ? 3 : ping < 90 ? 2 : 1;
    const heights = [4.0, 8.0, 13.0];
    return Row(
      mainAxisSize: MainAxisSize.min,
      crossAxisAlignment: CrossAxisAlignment.end,
      children: List.generate(3, (i) {
        return Container(
          width: 3,
          height: heights[i],
          margin: EdgeInsets.only(left: i == 0 ? 0 : 2),
          decoration: BoxDecoration(
            color: i < level ? c.success : c.borderStrong,
            borderRadius: BorderRadius.circular(1),
          ),
        );
      }),
    );
  }
}