import 'dart:async';
import 'package:flutter/material.dart';

class ActivityCountdownView extends StatefulWidget {
  final Duration duration;
  final TextStyle? textStyle;
  final BoxDecoration? timeBgBoxDecoration;
  final double? timeItemWidth;
  final double? timeItemHeight;
  final BoxFit bgFit;
  final EdgeInsetsGeometry contentPadding;
  final Widget? separator;
  final VoidCallback? onFinish;

  const ActivityCountdownView({
    super.key,
    required this.duration,
    this.timeBgBoxDecoration,
    this.textStyle,
    this.timeItemWidth,
    this.timeItemHeight,
    this.bgFit = BoxFit.contain,
    this.contentPadding = const EdgeInsets.all(4),
    this.separator,
    this.onFinish,
  });

  @override
  State<ActivityCountdownView> createState() => _ActivityCountdownViewState();
}

class _ActivityCountdownViewState extends State<ActivityCountdownView> {
  late Duration _remaining;
  Timer? _timer;

  @override
  void initState() {
    super.initState();
    _remaining = widget.duration;
    _startTimer();
  }

  void _startTimer() {
    _timer = Timer.periodic(const Duration(seconds: 1), (_) {
      if (_remaining.inSeconds <= 1) {
        _timer?.cancel();
        widget.onFinish?.call();
        setState(() {
          _remaining = const Duration(seconds: 0);
        });
      } else {
        setState(() {
          _remaining -= const Duration(seconds: 1);
        });
      }
    });
  }

  String _twoDigits(int n) => n.toString().padLeft(2, '0');

  @override
  Widget build(BuildContext context) {
    final hours = _twoDigits(_remaining.inHours);
    final minutes = _twoDigits(_remaining.inMinutes.remainder(60));
    final seconds = _twoDigits(_remaining.inSeconds.remainder(60));

    return Row(
      mainAxisSize: MainAxisSize.min,
      children: [
        _buildTimeBox(hours),
        _buildSeparator(),
        _buildTimeBox(minutes),
        _buildSeparator(),
        _buildTimeBox(seconds),
      ],
    );
  }

  /// 自定义时间数字块，2位合并显示
  Widget _buildTimeBox(String text) {
    return Container(
      width: widget.timeItemWidth,
      height: widget.timeItemHeight,
      alignment: Alignment.center,
      padding: widget.contentPadding,
      decoration: widget.timeBgBoxDecoration,
      child: Text(
        text,
        maxLines: 1,
        style: widget.textStyle ??
            const TextStyle(
                fontSize: 20, fontWeight: FontWeight.bold, color: Colors.white),
      ),
    );
  }

  /// 自定义分隔符（冒号），如果未设置就给默认间距
  Widget _buildSeparator() {
    return widget.separator ??
        const SizedBox(
          width: 4,
        );
  }

  @override
  void dispose() {
    _timer?.cancel();
    super.dispose();
  }
}